Cel Kulasekaranhttp://cel.kulasekaran.net/feed.xml2023-12-11T15:16:16.914000ZWerkzeugHow to Predict the Future Performance of NBA Draft Prospectshttp://cel.kulasekaran.net/post/how-to-predict-the-future-performance-of-nba-draft-prospects2023-11-30T21:44:38.627000Z2023-09-08T20:21:30ZCel Kulasekaran<p>Working paper that describes a new mathematical system for predicting outcomes of NBA draft prospects.</p>
<p>Czasonis, Megan, Mark Kritzman, Cel Kulasekaran, and David Turkington, MIT Sloan Working Paper 6955-23, September 2023.</p>
<p>See <a href="https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4566449">https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4566449</a></p>Portfolio Construction When Regimes are Ambiguoushttp://cel.kulasekaran.net/post/portfolio-construction-when-regimes-are-ambiguous2023-11-02T13:15:03.517000Z2023-04-13T16:06:51ZCel Kulasekaran<p>Working paper for a new concept called relevance to estimate regime-specific expected returns, standard deviations, and correlations. This relevance-based approach to portfolio construction explicitly accounts for the importance of an observation to forming an estimate, and it seamlessly enables the inclusion of multiple regime indicators in a principled way.</p>
<p>See <a href="
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4422674
"><br />
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4422674<br />
</a></p>
<p>2023-11-01 update:<br />
Published in the Journal of Portfolio Management Volume 50, Number 1 (November 2023).<a href="
https://doi.org/10.3905/jpm.2023.1.538
"><br />
https://doi.org/10.3905/jpm.2023.1.538<br />
</a></p>
<p style="text-align:center">
<img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/d5ec111d-4f74-02a4-72d6-a44fd7782001/1f365ed9-a313-03e3-6a02-0062cb980e22.png" style="--en-naturalWidth:550; --en-naturalHeight:550;"/></p>The KN-001 Flying-V Electric Guitarhttp://cel.kulasekaran.net/post/the-kulasekaran-flying-v-kn-001-electric-guitar2023-12-11T15:15:08.416000Z2022-06-11T18:00:16ZCel Kulasekaran<p><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/43878fc2-4764-eea3-7c36-13ced643a6e6/451013ab-5a3e-8ca7-0de1-4d522110dba4.png" style="--en-naturalWidth:938; --en-naturalHeight:1456;"/><blockquote><p>Made by the Rock Hero of Kuala Lumpur for his heir and all the shred glory in the world.</p><br />
<p>Body: Alder, '67 V-shape, rear-routed<br />
Artwork: Nigel Kulasekaran<br />
Neck: Maple, 24-frets, compound radius, 25.5" scale, Tung-oil finish<br />
Pickups: DiMarzio Super Distortion (bridge), Seymour Duncan Hotrails (neck); direct mount<br />
Three-way toggle switch, 1 Volume, and 1 Tone<br />
Hardware: Gotoh Locking Tremolo and Machine Heads<br />
Ernie Ball Slinky Cobalt Strings</p></blockquote></p>
<p>Seven years in the making and finally ready to rock! A journey of exploration, anticipation, and pride. Inspired by interactions and consumption of George Lynch, Michael Schenker, and Steve Morrill's work. The body shape is based on Gibson's '67 model and is rear-routed for a humbucker-single combination, a configuration that I find the greatest utility for. The initial plan was to use Basswood similar to my other workhorse guitars, however, I went for Alder because it is a little harder and would be more robust given its radical body shape. The body artwork, hand-drawn by my son, was carefully sealed with several layers of semi-gloss clear coat. <br />
<img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/43878fc2-4764-eea3-7c36-13ced643a6e6/f894f96e-f724-a24a-ab81-861ae0256b2e.png" style="--en-viewAs:attachment;"/>The neck is atypical for a Flying-V, it has a scale length of 25.5" with 24 frets instead of a 24.75" scale with less frets. The neck is finished with Tung oil and plays fast.</p>
<p>In May, I was asked to join the teaching artists of the <a href="https://www.bostonmusicproject.org/">Boston Music Project</a> for an upcoming performance at their 10 year anniversary event. They wanted to have a surprise insert in their set list for the evening. This accelerated the drive for completion. </p>
<p>The pickups are direct mounted with a DiMarzio Super Distortion F-spaced in the bridge and an old Seymour Duncan Hotrails in the neck position. DiMarzio really came through on the custom color for the Super Distortion with very a timely turnaround. The bridge pickup is a 4-conductor Ceramic magnet humbucker with a resistance of 13.68 Kohms. The initial plan was to solder a coil-split option, but opted to keep the schematics simpler because I was rushing to finish the project for the BMP performance. The Hotrails in the neck is also a Ceramic magnet with a resistance of 10.9Kohms, it has been my favorite for decades.</p>
<p><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/43878fc2-4764-eea3-7c36-13ced643a6e6/1385f8b3-662c-d207-e27c-8234d29e516f.png" style="--en-viewAs:attachment;"/></p>
<p>Gotoh hardware for the locking tremolo, nut, and machine heads were challenging to source with the time-crunch. The locking tremolo studs and nut were also difficult to manage without the right industrial tools, but prevailed with the help of a trusted Dremel. I think that Gotoh makes really high quality hardware.</p>
<p><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/43878fc2-4764-eea3-7c36-13ced643a6e6/a300a832-cb4f-4763-f6ff-251f640a6a5d.png" style="--en-naturalWidth:1053; --en-naturalHeight:891;"/><blockquote><p>The current schematic of the wiring soldered for this guitar, June 2022</p></blockquote></p>
<p>This project took many years without a dedicated workshop space. Being opportunistic with tools in tow during family vacations across New England's country side was necessary to usher progress. I finished KN-001 on the eleventh hour of Boston Music Project's 10-year anniversary; I began with a shred-take on Bach and we jammed a semi-spontaneous rendition of Schenker's Coast to Coast (Em) with the non-profit's wonderful teaching artists. Fantastic time for a good cause.</p>
<p><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/43878fc2-4764-eea3-7c36-13ced643a6e6/39a0e659-ebb3-d756-e87a-74711ca739be.png" style="--en-viewAs:attachment;"/></p>
<blockquote><p>Jamming with Sébastien Ridoré (viola), Christopher Schroeder (drums), Chris Hernandez (bass), Scott Ziegler (bass synth), and Rafael Nocedo (keyboard)</p><p>Post Office Square, Boston, MA<br/>Photograph by Kevin Trimmer</p></blockquote>
<p>Big thanks to my wife, kids, and neighbors for supporting this awesome project. Special thanks to Chris Schroeder and the teaching artists of the Boston Music Project.</p>Excel Lab, a Quant Libraryhttp://cel.kulasekaran.net/post/excel-lab2023-09-07T20:18:06.101000Z2021-01-12T17:06:51ZCel Kulasekaran<p>One of the benefits of the COVID 19 quarantine for me is uninterrupted time for deep work. I've often found even with access to an array of technical tools such as WPA / Matlab / R / C++ / Microsoft Excel that it is sometimes convenient and valuable to prototype or build out ideas in a single platform if possible. </p>
<p>I can now retrieve data from Bloomberg or Datastream in Excel, use native Microsoft functions, and extend that with more complex quantitative models specific for asset allocation, portfolio construction, and risk management.</p>
<p>I hope this allows buy-side analysts and asset owners across the globe to improve their workflow in Microsoft Excel and mitigate errors from using disparate tools.</p>
<p>Watch this cool video on the tool:</p>
<div class="wistia_responsive_padding" style="padding:56.25% 0 0 0;position:relative;"><div class="wistia_responsive_wrapper" style="height:100%;left:0;position:absolute;top:0;width:100%;"><iframe src="
https://fast.wistia.net/embed/iframe/
gxhqhsfora
?videoFoam=true
" title="Scenario Lab Video" allow="autoplay; fullscreen" allowtransparency="true" frameborder="0" scrolling="no" class="wistia_embed" name="wistia_embed" allowfullscreen msallowfullscreen width="100%" height="100%"></iframe></div></div>
<script src="
https://fast.wistia.net/assets/external/E-v1.js
" async></script>Severe but Plausible - or Not?http://cel.kulasekaran.net/post/severe-but-plausible-or-not2023-09-07T20:18:06.979000Z2021-01-09T17:06:51ZCel Kulasekaran<p>Working paper on an application of statistical unusualness to assess the plausibility of the Federal Reserve's stress scenarios.</p>
<p>See <a href="
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3764123
">https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3764123</a></p>
<p>2022-02-21 update:<br />
Published in the Journal of Risk Volume 24, Number 3 (February 2022).<br />
<a href="
https://doi.org/10.21314/JOR.2021.026
">https://doi.org/10.21314/JOR.2021.026</a></p>
<p><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/1b962a21-783c-a13c-9e5c-10de25cfa436/04fe4590-52a0-6490-2a1e-306f08644772.jpg" style="--en-naturalWidth:800; --en-naturalHeight:811;" alt="No alternative text description for this image"/></p>Enhanced Scenario Analysishttp://cel.kulasekaran.net/post/enhanced-scenario-analysis2020-10-07T13:50:26.491000Z2020-10-06T16:06:51ZCel Kulasekaran<p>I've been keeping myself out of trouble this summer and spending what little quiet time earned during the pandemic engaging with the research and development team building very cool technology around some of our recent <a href="
https://www.statestreet.com/content/dam/statestreet/documents/ss_associates/JPM%20Enhanced%20Scenario%20Analysis.pdf
">research ideas</a> in asset allocation and risk management. Watch this cool video:</p>
<div class="wistia_responsive_padding" style="padding:56.25% 0 0 0;position:relative;"><div class="wistia_responsive_wrapper" style="height:100%;left:0;position:absolute;top:0;width:100%;"><iframe src="
https://fast.wistia.net/embed/iframe/xqihytsvlq?videoFoam=true
" title="Scenario Lab Video" allow="autoplay; fullscreen" allowtransparency="true" frameborder="0" scrolling="no" class="wistia_embed" name="wistia_embed" allowfullscreen msallowfullscreen width="100%" height="100%"></iframe></div></div>
<script src="
https://fast.wistia.net/assets/external/E-v1.js
" async></script>Beta Distribution (Pearson) Simulatorhttp://cel.kulasekaran.net/post/beta-distribution-pearson-simulator2023-11-02T13:14:19.014000Z2020-02-27T15:41:21ZCel Kulasekaran<p>Occasionally, after the family falls asleep, I sneak away into the kitchen to play around with some math and tech. I recently built a <a href="http://cel.kulasekaran.com/apps/pearson">micro-application</a> to simulate a four-parameter beta distribution using the <a href="https://en.wikipedia.org/wiki/Pearson_distribution">Pearson system</a>.</p>
<p style="text-align:center">
<img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/bc609205-930c-4e0a-97a1-d27c5fb0954a/a946702a-4e71-43ee-9a91-fe746d284c38.png" title="Tap to Download"/></p>
<p>The <a href="http://cel.kulasekaran.com/apps/pearson">Pearson Simulator web app</a> is available for use <br />
on my server weekdays between 14:00 - 15:00 GMT<br />
. Please note that this is experimental.</p>
<h2>Important Notes</h2>
<ul>
<li>Be mindful of combinations of moments. i.e. Kurtosis > Skewness² + 1.</li>
<li>Since this is a micro-server prototype, I have limited the application to a maximum of three instances. Be patient for recomputing / refresh rates. </li>
<li>Each instance has a five minute timeout, so if you are unable to access or use the app - you will have to wait a little while until a resource is free.k</li>
</ul>Rubik's Cube 3x3 Noteshttp://cel.kulasekaran.net/post/rubiks-cube-3x3-notes2022-08-04T17:20:52.675000Z2019-09-12T14:04:57ZCel Kulasekaran<div>Personal notes on solving 3x3 cube. </div>
<div><br /></div>
<div>Edit: Don't do this often enough, additional notes for the third layer </div>
<div><br /></div>
<div><b><u>Third Layer Surface Cross</u></b></div>
<div>third layer: <span style="--en-highlight:green;background-color: #b7f7d1;">F R U R' U' F'</span></div>
<div><br /></div>
<div>Repeat this three time if only yellow center is valid.</div>
<div>Repeat this twice if yellow layer is a small L away from front side.</div>
<div>Repeat this once if yellow is a horizontal line left-right.</div>
<div><br /></div>
<div>This should result in a yellow-cross on the top-surface only!</div>
<div><br /></div>
<div><b><u>Third Layer Surface Cross Walls</u></b></div>
<div>This rotates the three edges away from the front face counter-clockwise. Do until the wall edges aligns with the cross.</div>
<div><br /></div>
<div><span style="--en-highlight:green;background-color: #b7f7d1;">R U R' U R U U R'</span></div>
<div><br /></div>
<div><b><u>Third Layer Corner Pieces</u></b></div>
<div>The following rotates the corner pieces in the rear triangular surface. Rotate until the top corner pieces are aligned.</div>
<div><br /></div>
<div><span style="--en-highlight:green;background-color: #b7f7d1;">U R U' L' U R' U' L</span></div>
<div><br /></div>
<div><b><u>Final Step</u></b></div>
<div>Flip the corner pieces closest to you Front/Right (re-orient), do this and always keep the corner you want to solve F/R. rotate the top surface. Keep doing this until the cube is solved!</div>
<div><br /></div>
<div><span style="--en-highlight:green;background-color: #b7f7d1;">R' D' R D</span></div>
<div><br /></div>
<div><br /></div>
<div>My notes, third layer was an older algorithm, which now I don't really recall to follow anymore (at least not how to solve the yellow cross)</div><a href="https://cdn-files.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/6f1ade3d-0721-44b6-b9eb-d097c22a9227/c839d4fc-59b7-4a67-b982-1a2d082beaab_orig.pdf" target="_blank">Download PDF</a><div><br /></div>
Deciphering Fedspeak: The Information Content of FOMC Meetingshttp://cel.kulasekaran.net/post/deciphering-fedspeak-the-information-content-of-fomc-meetings2017-10-02T18:09:57.236000Z2017-09-26T04:54:19ZCel Kulasekaran<div>Discussant for <a href="https://michiganross.umich.edu/faculty-research/faculty/andrew-wu">Andrew Wu (University of Michigan)</a> at the Journal of Investment Conference, Fall 2017.</div>
<div><br/></div>
<div><b>Abstract:</b> Jegadeesh and Wu present a new approach to quantify the economic and policy content of the Federal Reserve communications by dissecting the Federal Open Market Committee (FOMC) meeting minutes into eight distinct economic topics. They examine the informativeness of the Fed's discussion of each of these topics for the stock market and for interest rates. The market finds the Fed's discussion of its policy stance, inflation and employment to be the most informative and its discussion of topics such as trade, consumption and investment are not informative.</div>
<div><br/></div>
<div>Jegadeesh and Wu's paper: <a href="https://cdn-files.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/949ad43d-d111-4d96-a8fd-377f843a5570/cfe3b6e6-d2d2-4ba2-9cd2-cc9ba11762cf_orig.pdf" target="_blank">Download PDF</a><br/></div>
<div>My slides: <a href="https://cdn-files.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/949ad43d-d111-4d96-a8fd-377f843a5570/4b380719-ebd1-45a1-837b-c849ac835989_orig.pdf" target="_blank">Download PDF</a><br/></div>
Investors Do Not Get Paid for Bearing Riskhttp://cel.kulasekaran.net/post/investors-do-not-get-paid-for-bearing-risk2017-10-16T19:23:55.983000Z2015-04-27T04:37:10ZCel Kulasekaran<div>Discussant for Harry Markowitz at the Journal of Investment Management Conference, Fall 2015.</div>
<div><br/></div>
<div><span style="font-weight: bold;">Abstract:</span> The relationship between the excess return of each security and its beta, where beta is defined as its regression against the return on the market portfolio, is linear in the Sharpe–Lintner (“S–L") Capital Asset Pricing Model (“CAPM"). This linear relationship is often interpreted to mean that CAPM investors are paid for bearing systematic risk. In this article, Markowitz will show that this is not a correct interpretation because two securities may have identical risk structures in terms of their covariances with other securities in the market, yet have different excess returns. In fact, if the parameters of the CAPM are generated in a natural way, then securities with the same risk structure almost surely will have different expected returns.</div>
<div><br/></div>
<div>My slides: <a href="https://cdn-files.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/e9408faa-0afe-4637-9fff-74eb08ee4317/5e2d0d20-e25e-488a-8e57-93a16b97313d_orig.pdf" target="_blank">Download PDF</a></div>
<div><br/></div>
<div>Markowitz's paper: <a href="http://hmarkowitz.com/wp-content/uploads/2015/02/Markowitz-2008-Article-CAPM-Investors-Do-Not-Get-Paid-for-Bearing-Risks.pdf">Working copy PDF</a>; <a href="https://doi.org/10.3905/jpm.2008.701620">Journal of Portfolio Management, Winter 2008</a></div>
<div><br/></div>
<div> </div>
<div><em>Markowitz also contributed this idea to Fabozzi's "The Theory and Practice of Investment Management", see Chapter 4 - which in hindsight, I think, does a comprehensive job of clearing up confusion with classical thoughts on CAPM.</em></div>
<div><br/></div>
<div><br/></div>
<div><br/></div>
Flipping an Edge on a 4x4 Rubik's Cubehttp://cel.kulasekaran.net/post/flipping-an-edge-on-a-4x4-rubiks-cube2022-08-04T17:22:50.886000Z2012-06-08T15:33:52ZCel Kulasekaran<div><div align="left"><font color="#010101" face="Calibri"><span style="font-size:11pt">r ² B ² U ² l U ² r ' U ² r U ² F ² r F ² l ' B ² r ²</span></font></div></div>
IFR with Bruce Dickinson, Flight BA666-0057http://cel.kulasekaran.net/post/ifr-with-bruce-dickinson2021-06-04T20:25:57.904000Z2011-12-17T17:05:49ZCel Kulasekaran<div>Got a lucky break and fulfilled one improbability. Spending some quality time with one of the most productive members of Iron Maiden, Bruce P. Dickinson, was a remarkable way to kick-off my 30s. We simulated nighttime flight-runs in Bruce's Boeing 737 on British Airways training grounds at Heathrow.</div>
<div><br /></div>
<div><table><tr></div>
<div><td></div><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/a1c63f15-2668-498d-9d1b-05ef538e29c4/94dbfef4-7ed0-466a-afd9-46d28e809315.jpg" style="--en-naturalWidth:640; --en-naturalHeight:426;" height="60px" width="300px"/><div></td></div>
<div><td></div><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/a1c63f15-2668-498d-9d1b-05ef538e29c4/ba5ac940-c058-4ee4-a3f5-5f4d1aaf94c8.jpg" style="--en-naturalWidth:640; --en-naturalHeight:426;" height="60px" width="300px"/><div></td></div>
<div></tr></table></div>
<div><br /></div>
<div>Bruce and I decided to fly IFR (night) around London and land at Heathrow. In retrospect, we should have picked day-time scenarios as I only had 13 hours of flight-time in smaller planes under my belt. I stared hard at the instruments without much time to enjoy the view between keeping the plane steady and Bruce’s passionate technical lectures.</div>
<div><br /></div><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/a1c63f15-2668-498d-9d1b-05ef538e29c4/3f9d4af0-4136-4c90-bad4-d06b9d4962b1.jpg" style="--en-naturalWidth:1024; --en-naturalHeight:768;" height="60px" width="300px"/><div><br /></div>
<div>I had the pleasure of having my friends Chirag and Kim (we've since married) along for the ride, they were patient passengers throughout Flight BA 666-0057.</div>
<div><br /></div>
<div><table><tr></div>
<div><td></div><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/a1c63f15-2668-498d-9d1b-05ef538e29c4/9c6bf9b2-d1f5-4395-b07f-aaa35c239084.jpg" style="--en-naturalWidth:640; --en-naturalHeight:426;" height="60px" width="300px"/><div></td></div>
<div><td></div><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/a1c63f15-2668-498d-9d1b-05ef538e29c4/b9b31c62-d11a-4016-91d3-dd60b4ec1943.jpg" style="--en-naturalWidth:640; --en-naturalHeight:427;" height="60px" width="300px"/><div></td></div>
<div></tr></table></div>
<div><br /></div>
<div><em>PS. We all got to ride in Bruce's WW2 land rover from the tube. What a riot.</em></div>
Cultivating Hemianthus Callitrichoides Emersedhttp://cel.kulasekaran.net/post/cultivating-hemianthus-callitrichoides-emersed2020-02-27T16:32:28.122000Z2011-02-16T18:50:39ZCel Kulasekaran<p style="text-align:center"><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/b2a35d4b-0496-414d-8e38-0b022c4a5469/e15baed5-1d57-4586-9755-a571bc048e11.jpg" title="Tap to Download"/>
<br/><strong>Iwagumi Padang</strong>, my planted tank, before kids.<br/>
Yes, that is a carbon dioxide canister pumping CO2 underwater!</p>
<blockquote>
<p>"Hemianthus callitrichoides, sometimes known as ‘dwarf baby tears’, or more commonly as ‘HC’, was discovered by Tropica founder Holger Windeløv during an expedition to a small rocky stream east of Havana, Cuba; it was described in aquaristic literature for the first time in 2003. Since its introduction into the hobby, HC has become increasingly popular and a foreground plant of choice, making this once rare plant moderately easy to obtain." - Aquatic Plant Central.</p>
</blockquote>
<p>I was first introduced to the world of aquascaping and Iwagumi through <a href="https://en.wikipedia.org/wiki/Takashi_Amano">Takashi Amano</a>. I find the field quite inspiring and complex. One of the first few aquatic plants I fell in love with were HC. As an initiate, I found that while there were a number of reading resources on HC available, they were not aggregated into a single coherent and comprehensive guide for these delicate beauties. This report is intended as a reference guide for anyone seeking to successfully replicate and cultivate a beautiful dense carpet of HC underwater.</p>
<h2>Emersed (Dry Start) or Submersed?</h2>
<p>I started cultivating HC emersed rather than submersed for the planted tank for three important reasons:</p>
<ul>
<li>
<p>Relatively quicker for HC to densely carpet my scape emersed;</p>
</li>
<li>
<p>Allowed roots to establish itself deeper into the soil. This prevented floaters when the tank was first flooded, which was extremely frustrating;</p>
</li>
<li>
<p>Algae threat is minimized to zero as it allows HC to establish its dominance prior to flooding;</p>
</li>
</ul>
<h2>Tank and Lighting</h2>
<p>The intended scape was housed in a tank and a good light source. I used a 20 liter (5.5 gallon) rimless tank with a 27W, 8000K power compact fluorescent bulb. This lighting arrangement works very well for a tank of this size and is sufficient for HC.</p>
<p style="text-align:center"><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/b2a35d4b-0496-414d-8e38-0b022c4a5469/2d51b750-98a1-4620-adc4-957be4fee201.jpg" title="Tap to Download"/></p>
<p>HC demands a substantial amount of light as it is a tropical plant, so I tried to replicate its natural habitat within an indoor setting for it to flourish (I am based in a continental climate zone). If you have to ask "do I have enough light?" - you probably don’t. At the very least, you should follow the two watts per gallon rule. It does not hurt to have more light. I used an 8000K lamp, which has the same spectrum as daylight.</p>
<h2>Substrate</h2>
<p>There are three layers to the substrate scape. First, I layered the bottom with ADA’s Powersand Special which is basically a fertilizer type substrate with additional nutrients and beneficial microorganisms.</p>
<p style="text-align: center"><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/b2a35d4b-0496-414d-8e38-0b022c4a5469/71f21dcf-648a-48e3-b396-917327b937ba.jpg" title="Tap to Download"/></p>
<p>Next, I add a layer (at least 4cm depth) of ADA Amazonia 1, Normal Type. This is the main substrate. I prefer this over Amazonia 2 (ADA has recently updated the composition) as it does not crumble easily once flooded and has a more desirable chemistry (less acidic) with my source of freshwater.</p>
<p style="text-align: center"><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/b2a35d4b-0496-414d-8e38-0b022c4a5469/ff766fc6-4915-4ccf-9852-b883ac0ad853.jpg" title="Tap to Download"/></p>
<p>Finally, I topped it off with Amazonia 1, Powder Type. The powder type has finer granularity which is much more suitable for HCs rooting.</p>
<p style="text-align: center"><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/b2a35d4b-0496-414d-8e38-0b022c4a5469/1ddd857d-6267-4766-af32-8d87dadf73d7.jpg" title="Tap to Download"/></p>
<h2>Hardscape</h2>
<p>I then added my hardscape. This included my choice of Seiryu stones. Once happy with the scape, I sprinkled a little more Amazonia Powder soil to cover any gaps and to make the hardscape seamless with the substrate (i.e. makes it look more natural).</p>
<h2>Planting</h2>
<p>This was the "fun" part. It will take time and patience to delicately plant your HC carpet. As with most gardening endeavors, it is easy to end up with a sore back.</p>
<h2>How many pots of HC do I need?</h2>
<p>I found that most aquatic plant suppliers will sell you HC in pots of rock wool. I started with about six or seven pots for a tank of this size. The more you have to start with, the faster it will carpet. I kept the pots in a humid Ziploc bag as I worked through planting.</p>
<h2>Do I need to remove rock wool or can I just plant HC with it?</h2>
<p>I removed it. It is a little extra work, but I found that as time goes by, I did not have to deal with excess dirt, rot, etc. and got better results.</p>
<p>I started by cutting off the excess rock wool at the very bottom with a sharp scissors. Next, I used tweezers to separate out the HC into smaller clumps or stems.</p>
<p>I wet the substrate so that it was uniformly moist as I found it easier to work with than a dry substrate. Using a mister and spray will help prevent flooding excess-watering.</p>
<p>Next, I individually planted these clumps/stems with a tweezer. Tweezers made it a lot easier, one’s fingers / hands are never small enough. When planting, I allowed about 5mm to 10mm of spacing between the clumps/stems. HC are no different than people as they need space to grow and flourish.</p>
<p style="text-align: center"><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/b2a35d4b-0496-414d-8e38-0b022c4a5469/f2277e7d-374a-43ed-8072-00de4479ac97.jpg" title="Tap to Download"/></p>
<h2>Humidity</h2>
<p>As the HC are from the tropics, they require high humidity when grown emersed. To control for this, I got a clear saran wrap and covered the top of the tank. This kept the humidity high and heat within bounds after a day’s worth of lighting. I was then done with the initial set up of the HC’s environment.</p>
<h2>Photoperiod</h2>
<p>I set my lights on a timer for 8-10 hours a day.</p>
<h2>The Daily Process</h2>
<p>I then followed this daily routine which requires under 10 minutes a day for the next month or two:</p>
<ul>
<li>
<p>Morning routine</p>
<ul>
<li>Morning wishes won't hurt your plant, probably relaxes you a little as well</li>
<li>then unwrap the saran wrap cover</li>
<li>then mist the whole terrain with water, including the hardscape</li>
<li>I then would cover the tank with saran wrap</li>
</ul>
</li>
<li>
<p>Evening routine</p>
<ul>
<li>I would inspect the tank without opening the saran wrap</li>
<li>If the hardscape appeared dry, it is an indication of insufficient humidity – I would mist more and check that the saran wrap is sealed is tight!</li>
<li>Get some rest</li>
</ul>
</li>
</ul>
<h2>How Long Before I Get My Carpet?</h2>
<p>Patience is key. The longer I waited, the more the HC established itself. It took about a month before I saw a dense carpet. I was not concerned that I did not notice any progress the first couple of weeks. I placed faith and trust in mother nature.</p>
<p style="text-align: center"><img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/b2a35d4b-0496-414d-8e38-0b022c4a5469/e15baed5-1d57-4586-9755-a571bc048e11.jpg" title="Tap to Download"/></p>
<h3>Important Notes</h3>
<ul>
<li>
<p>Misting excessively during the daily routine caused flooding in the soil. Flooding / excessive pools of water are not desirable as partially drowned HC will require CO2 supplements and will take longer to establish;</p>
</li>
<li>
<p>I kept the tank in a relatively warm place, avoiding cold droughts;</p>
</li>
<li>
<p>I avoided unwrapping the saran wrap at night as heat trapped from the photoperiod will dissipate. Heat is good, it encourages faster growth. So I confined all unwrapping / open air maintenance work on the tank to the mornings at the start of the photoperiod;</p>
</li>
<li>
<p>Every two or three days, the saran wrap will cumulate water from evaporation / humidity (dew). Replace the saran wrap so that layer of dew would not decrease light exposure;</p>
</li>
<li>
<p>The hardscape (stones) and glass walls of the tank are good humidity indicators. If they appeared dry, I would immediately mist more and ensure that the saran wrap is sealed tightly. I also considered increasing the misting dose every morning;</p>
</li>
<li>
<p>I refilled water in the mister with overnight tap-water. This reduced chlorine traces. I usually use water from my refrigerator’s filter. Alternatively, Brita-filtered tap-water is preferred to unfiltered tap-water.</p>
</li>
</ul>
<h3>Frequently Asked Questions, Concerns, and Fallacies</h3>
<p>HC will suffocate if I do not leave a small gap in the saran wrap seal.</p>
<blockquote>
<p>On the contrary, the HC did dry out over time and perished when I left a small gap in the saran wrap seal in one of my early experiments. The subsequent trials proved that the seal needed to be tight, air-flow is sufficient during the execution of daily misting in the mornings - sufficient to sustain growth and life until the next morning.</p>
</blockquote>
<p>Is it okay to miss a day of the daily routine? They are plants after all and plants have slow reaction times.</p>
<blockquote>
<p>I found that HC are quick to perish from neglect as they are extremely sensitive and delicate.</p>
</blockquote>
<p>The soil seems a little flooded.</p>
<blockquote>
<p>It took me awhile to practice a balanced level of daily misting. Excessive water will cause mold/algae to grow in the cumulated pools of water. This creates difficulty for HC growth in establishing roots and new stems. I used a syringe to extract excess cumulated water.</p>
</blockquote>
<h2>Other Resources</h2>
<p>External resources related to this article:</p>
<ol>
<li><a href="http://www.plantedtank.net">Planted Tank Forums</a></li>
<li><a href="https://www.plantedtank.net/forums/12-tank-journals/124525-janicks-ada-mini-m-cube-garden-iwagumi-padang.html#post1247307">My Planted Tank discussions of progress</a></li>
<li><a href="http://www.aquaticplantcentral.com/forumapc/plantfinder/details.php?id=51t">Hemianthus Callitrichoides on Aquatic Plant Central</a></li>
<li><a href="http://www.adana.co.jp/en/aquajournal/">Aqua Journal Online</a></li>
</ol>
<p><em>I thank Jordan Alexiev and Kimberly Phillips for assistance throughout my experiments. I have also learnt a lot from discussions with members of the PlantedTank forums. I am in no way affiliated with ADA.</em></p>The Windham Portfolio Advisorhttp://cel.kulasekaran.net/post/windham-portfolio-advisor2018-11-28T19:18:21.246000Z2010-12-23T16:02:51ZCel Kulasekaran<p>The genesis of Windham's technology arm, The Windham Portfolio Advisor, is an asset allocation and risk management software. I designed and co-engineered its technology with Tim Adler at Windham six years ago (2004) as a follow-up to the Chow-Kritzman Optimizer. The video below showcases version 2.5 which was developed in C++; the underlying quantitative library is compiled as a Matlab DLL.</p>
<p style="text-align:center"><div class="responsive-embed embed-16by9"><iframe width="480" height="360" src="https://www.youtube.com/embed/gNq4g7RGVwU?feature=oembed" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe></div></p>
<h3>Fast-forward to 2017</h3>
<p>The current version, 3.0, has an upgraded .NET 4.0 framework technology, updated user interface and additional modules. The latest revision uses a publisher-subscriber design pattern to persist objects and its business models (in mathematics, this is a special case of Bayesian networks with binary conditional joint probabilities of 1s or 0s). </p>
<p style="text-align:center"><div class="responsive-embed embed-16by9"><iframe width="640" height="360" src="https://www.youtube.com/embed/nJGcteg4pcc?feature=oembed" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe></div></p>
<p>The technology team continues to innovate and is working on new derivatives and a universal web platform. See <a href="https://www.windhamlabs.com">Windham Labs</a> for the wonderful work by the business development group and the R&D team.</p>Comparing the PAR-11 against the HiHo-9 Scoring for Squashhttp://cel.kulasekaran.net/post/comparing-the-par-11-against-the-hiho-9-scoring-for-squash2017-10-02T02:32:05.548000Z2009-08-31T17:57:00ZCel Kulasekaran<div>Monte-carlo simulation to observe statistics for contrasting the point-a-rally scoring system to the hand-in hand-out scoring system debate in 2009 by the MA Squash.</div>
<div><br/></div>
<div>The Matlab program assumes a simple parametric distribution when computing the probabilities of winning a rally. The script plays 5000 games between two players and varies the probability of winning a rally. </div>
<div><br/></div>
<div>Conclusion, unless your skill gap against your opponent is zero - you never want to choose Hi-Ho scoring.</div>
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<div><a href="https://cdn-files.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/8f86e79d-7532-4e98-9af1-186e705c6dd8/355c8049-0985-49ae-a446-747deb3bd8fe_orig.pdf" target="_blank">Download PDF</a><br/></div>
<div><br/></div>
<div><a href="https://github.com/ckulasekaran/PAR-11-vs-HiHo-9-Scoring-for-Squash">https://github.com/ckulasekaran/PAR-11-vs-HiHo-9-Scoring-for-Squash</a></div>
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Designing a Performance Roomhttp://cel.kulasekaran.net/post/designing-a-performance-room2023-12-11T15:16:16.914000Z2002-10-10T17:23:55ZCel Kulasekaran<p>This project involves finding and treating acoustical problems in a small studio space (WICN Public Radio 90.5FM) to improve its acoustic environment. The approach was to consult professionals and literature in acoustics, set up a computer model of the acoustic problems, and run acoustical tests. The project concludes the presence of modal problems and an irregularly distributed reverberation time, which needed to be addressed. Recommendations and analysis suggested the implementation of RPG Inc.'s Modex solutions complemented by a constructed performance stage.</p>
<p><a href="https://cdn-files.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/ec4c5ecd-b7de-4637-913b-9698a4ba9a3c/b65d3d54-3f6f-4642-82b0-cfd5824f3205_orig.pdf" target="_blank">Download PDF</a></p>
<p style="text-align:center">
<img src="https://cdn-images.postach.io/0511b6fa-0991-42eb-8a03-6aea32f5438b/ec4c5ecd-b7de-4637-913b-9698a4ba9a3c/688a560d-74b5-4cad-b0fc-067579d95222.png" height="60" width="300"/>
</p>
<p><em>[2013] It was a great privilege to work with the late <a href="https://www.wpi.edu/sites/default/files/docs/Offices/Alumni/2013_AW_Citations11-Rcampbell.pdf">Richard Campbell</a> of Bang-Campbell Associates. He was very generous in entertaining my curiosities and interests in audio engineering.</em></p>