A Common Choice: Hydroponic Drip SystemThere are different places where hydroponic system plans can be found, either for free (DIY) or for purchase at a retailer. There are companies that will sell hydroponic drip systems pre-made. These systems can be more simple than trying to follow a plan to build a drip system. Building a system from scratch, although fairly simple, still leaves the possibility of not doing something correctly which will make the system ineffective. Buying a pre-made system allows you to have a system that is up and running quickly and that is guaranteed to work for years to come.Wick versus DripThere are two systems that are most commonly made from scratch and those are the wick system and the drip hydroponic system. The wick system is very simply constructed. It uses a tray that holds the plants which sits on top of the reservoir that holds the water and nutrient solution. These two pieces are held together by a wick which allows the water solution to transmit these elements into the tray with the plants. The down side to this system is that there is not a way to regulate the amount of solution that is getting to the plants, which means that a small amount of plants can be grown at one time. This would make an ideal choice for someone wanting to grow a limited amount of plants or with very limited space.The drip hydroponic system is built in much the same way with the tray that sits on top of the reservoir. In this system, however, instead of using wicks to transmit the solution to the plants, there is a submerged pump system that transmits the solution to the plants at whatever rate the gardener sets on the meter. The solution goes into the tray a drip at a time so that there is a constant flow of nutrients without the plants becoming overly submerged like in other systems.There are benefits to using the drip hydroponic system, such as the fact that you do not have to monitor the system as often as other systems because the pump and timer handles everything automatically. Also, since the flow rate can be regulated, plants tend to grow larger, have a higher yield, and higher numbers of plants can be grown at one time in the system. One down side to using the drip hydroponic system is that it is more expensive than the wick system since the pump for the system has to be bought as well. However, this is a popular system, especially for use in greenhouses where larger numbers of plants are grown at a time.
Category Archives: Uncategorized
When to Turn Your Trading System Off and When to Turn It Back On
One of the most difficult decisions that every automated trader has to make is when to turn the system off because its performance is starting to be questionable and when to turn the system back on because it is getting back to profits. In this article, I will try to describe the way I see it.First of all, I need to say that this is one of the most difficult questions in automated trading. In the past, I made a lot of mistakes by turning the systems too early off or by turning them too early back on. To make things even more complicated, out of many ways that I have tried, there isn’t one rule that would stand out (negatively or positively) among others. Therefore, it is important to pick one and never break it.TURNING THE SYSTEM OFF1. Turn the system off when it exceeds 1.5 times of the drawdown of your backtesting equityI set this rule in my early beginnings. There are several important facts about it that I need to point out.First of all, this rule is good and bad at the same time. It depends on the backtest equity you use. In the past, I preferred to pick one optimization parameter set and apply it to the whole data history. More recently, I have started using regular reoptimization, when I combine several out of sample periods (each with different parameter set) and create one out of sample equity.Retrospectively, I must admit that in the case of one parameter set applied to the whole data history, this rule of 1.5 times of the drawdown wasn’t really the optimal solution. The equity of one parameter set was too “in-sample” – i.e. the backtested history was almost always better than live results (which is usual). Therefore I turned the systems off too early and experienced losses quite often – should I have the system turned on a little longer, the system would have, in most cases, recover.But you get completely different results when you use equity curve composed of several out of sample periods – as part of regular reoptimization. This equity is far more realistic in terms of what future results you should expect. So far it seems that this equity, composed of several out of sample intervals, is really realistic and the rule of 1.5 times the max. historical drawdown works very well in this case.2. To determine the moment when to turn it off, use Monte Carlo drawdownDespite the simplicity of the concept described above, I prefer the second method – using Monte Carlo analysis.Again, you need to consider if you work with equity that uses just a simple parameter set, or if you work with equity curve composed of several out of sample intervals.If we use a single parameter set for the whole history, then I find the Monte Carlo method better than the rule of 1.5 times the drawdown. When using Market System Analyzer for Monte Carlo calculation, you will get drawdown much bigger than 1.5x the drawdown and you don’t turn off the system too early. Moreover, what is really important here is that Monte Carlo really makes sense as the distribution of your future profits will be every time unique and different from the previous ones. So I consider Monte Carlo as a fundamental (and for me a primary) tool.Recently, I have started to incline more to using Monte Carlo, even on the equity composed of several out of sample periods. I agree that drawdowns that you will get using this method are not very nice. On the other side, the numbers will prepare you for the worst possible scenario, so that you can create your portfolio wisely and capitalize properly. This is the method I currently use. Though it is conservative, it matches my trading style.Most of the time I use equity curve composed of out of sample intervals, I run the Monte Carlo Analysis, note the 95% confidence level and the maximum drawdown that I get there is the point when I turn my system off – in case it is exceeded.This is the approach that makes the most sense to me.TURNING THE SYSTEM BACK ON1. Turn the system back on when the equity gets above the point when it was turned offWhen can I turn the system back on? It is even more difficult question then when to turn it off – at least for me. Many systems come back to life and start being profitable again. I have experienced this many times. One of the rules you can follow is to note the point when you have turned the system off and turn the system back on when the system gets above this point. Usually, the strategy continues in the drawdown for some time after you turn it off, but then it starts growing up again and quickly gets to the point when you turned it off. This approach I consider pretty aggressive, so let me get to the modification of this method that I prefer.2. Turn the system back on when it is “fully recovered”For a long time, I have used a rule to turn the system back on when it is fully recovered and makes new equity high. This rule works pretty well, even though the recovery sometimes can take up a year, or even longer. Still, I brought back several systems back to live trading using this rule and I consider it acceptable.What bothers me on this approach is that is too “binary” and also the fact that the recovery is sometimes so fast and so profitable that you miss some really nice profits. But on the other side, there is the previous method, which is really too aggressive for me.So, what I find to be the best approach is the combination of both.3. Combination of both using progressive position sizingThe rule is to turn the system back on as soon as it reaches the point when it was turned off (method #1), but start trading it with a minimum number of contracts. As the system recovers, we start adding some more contracts.Let’s say we have traded this system with three contracts. As soon as the system gets above the point when we have turned it off (or some acceptable level above this point), we start trading it with 1 contract. If the system recovers to the half of the drawdown, we add the second contract. And if the system gets fully recovered, we add the third contract as well.At the moment, I find this method to be the best one. Currently, it is my preferred way as it uses the best of both methods.THE RULE OF THUMBWhatever rule you decide to follow, the most important is to keep using just one rule. Be absolutely conscientious. I have a lot of students who lost a lot of money just because they didn’t turn the system off at the pre-defined point. They switched themselves to so-called “hope mode” and they started hoping that the strategy will turn up and start growing again. But this moment never came and their loss got bigger and bigger.You must be uncompromising in keeping of these rules and comply with them to 110%. It is painful to turn off the system, we have spent a lot of time on. But this is why we have a portfolio – we will always have systems that will fail, despite all our effort. We are not in a secure business, we are in the business with risks that we need rationally and professionally manage and control. The good news is that it is possible.Happy Trading!
Colleges and Education: Are Students Really Being Educated?
My associates in the financial service industry acknowledge that college graduates from United States universities are generally unprepared for entry-level professional positions. They have particularly noticed a drop in basic skills. Students who were once hired from accredited second-tier universities can no longer be relied upon to meet even minimal standards in many professional entry-level positions. (Note: I refer to top-tier as only one to two dozen colleges across the nation. These are Ivies and several select colleges such as MIT and Johns Hopkins.)A business executive may hire a graduate from what he believes is a top-performing business school that also boasts a nationally ranked football team into a marketing or customer service assignment. (Colleges that sport nationally ranked teams are characteristic of second-tier schools.) He must spend valuable time coaching and monitoring the new employee as the graduate lacks the most basic core skills. But executives today just do not have the time to do this in a time-stressed high-pressured corporate environment.Managers are shocked by poor writing and language skills of recent graduates.The situation is far worse than you might imagine. The results of my interviews with business people in many corporations conclude that students cannot function effectively in their chosen fields of study. Also, they often are severely deficient in written language and reasoning skills required to make incisive judgments and decisions. The standards have sunk so low that many students from second-tier universities cannot write a paragraph without making a major spelling or grammatical mistake.Yet the universities continue to accept the students in far greater numbers than in past decades, and offer little effective remedial help for students in need. And what is most distressing is that, as a result of grade inflation, almost every student can graduate from an accredited college today while receiving little or no help from their universities to rectify severe learning problems.Professors have little experience in their field and have no incentive to teach effectively.Full-time professors have their PhD but little real-life experience in their field of study. Consequently, at the end of four years, students have little acquired knowledge and cannot think critically in their chosen career field. Professors, especially those who have tenure and are almost impossible to relieve, show little concern with their own job performance and have relatively little incentive to instruct to high standards.It’s a fact!You don’t have to take my word alone for any of this. In one of the few honest and broad-based surveys of businesses conducted by an academic association, the Association of American Colleges and Universities in January of 2007 disclosed that two-thirds of the employers surveyed said that college graduates lack the skills to succeed in today’s economic environment. In fact, more than 70 percent said colleges just weren’t doing the job of emphasizing critical and analytical reasoning as well as creativity and innovation. These are just the things that colleges hang their hats on when trumpeting the value of a college education. Think of how really bad this is.If the education is so bad, who can we hire?So what can an executive do? She will hire only from top-tier schools that recruit their incoming freshmen from the very top of their high school classes. If her field is highly specialized, she may even go outside the country and recruit students from Asia, India or Argentina (hotbeds of Information Technology) where professors have experience in their fields. The students from these schools will have the knowledge, the tenacity, and, hopefully, the appetite to get the job done professionally.With few job prospects, most graduates are coming out of college with nothing to show for their four years. They don’t even receive an education.