## Dual Citizenship – Has there ever been a case of embassy asking for proof of the right to be in the current country when applying for a visa?

Aside from the countries where trapping dual citizens is not allowed, an essential part of applying for a visitor visa is that you are closely connected to your home and plan to return after your visit. If you are in a country where you are not a citizen in the long term, the consulate would like to make sure that your situation there is legal and stable and that you can return. If you are in country A without legal status, country B is unlikely to issue you a visa because they reasonably fear that you are likely to land in your country without legal status.

Britain is one such example. In your Evidence Guide: Visits to the UK, they're listed under "Other Documents You May Want to Provide – All Visitors":

Confirmation of legal residence if you are not a national of the country in which you are applying or if your right of residence is not included in your passport

Similarly, France notifies those who need short-term visas and are applying from the United States:

If you are not a US citizen, please submit your legal status (green card, visa and I94 or I20 for holders of an F1 visa or DS2019 for holders of a J1 visa. The signature "Travel Endorsment" is valid for one year and must be valid for one year not expire before the date of return to the U.S.).

France is not there to enforce the U.S. Immigration Law, but it wants to make sure that visitors are likely to leave France at the end of their stay.

## Java polymorphism case study

I know this is supposed to be a pretty sophisticated example to demonstrate the idea in the game. But I would say that as a rule of thumb, you want to exhaust all possible options before you rely on subtype polymorphism. Using composition is a better solution here, just based on the domain.

Marriage no longer defines a "type" of a person as race, wealth, interests, etc. The use of subtype polymorphism to model this case is therefore inappropriate. On a technical level, most languages ​​only support single inheritance. So if you had classes for `MarriedPerson`, `PacificIslanderPerson`, and `WealthyPerson`They would have no way of "composing" them together to describe a wealthy married Pacific Islander.

Instead, you would use a simple composition in yours `Person` Class.

``````public class Person {
public MarriageStatus marriageStatus;
public Race race;
public Wealth wealth;
}
``````

Here, `MarriageStatus`, `Race`, and `Wealth` everything can be individual responsibility and is probably fairly simple. An example of MarriageStatus could be.

``````public class MarriageStatus {
public Datetime anniversary;
public Person husband;
public Person wife;

// TODO: In the future the stakeholder would like to support polyamort
//  public List spouses;
}
``````

If you use a programming language such as Haskell or Rust with features (type classes in Haskell language use), you can automatically have the person behave like a married person from the point of view of the function. In a more traditional OOP language, your business logic would simply work `MarriageStatus`, `Race`, and `Wealth` Objects. You would only accept a `Person` when an interaction between these three compound properties is required.

In this way you have developed out of the recursive relationship and all the pitfalls.

I apologize if I have completely missed the point of your question. In particular you say

The person object would still exist, which is bad.

I don't think that's absolutely true. If you return a MarriedPerson object and there are no references to the original "person", the garbage collector simply comes over and removes the old "person" object. But I could misunderstand you.

## Pie Chart – Is There a Use Case for Date Pie Charts?

I don't like pie charts. They have many documented shortcomings. However, some of our customers still love them, so we support them.

The question is, is there a valid use case for a pie chart cut by date? Like every segment is a different date.

I cannot imagine why it would be beneficial to display the information in this format.

## Is it possible to know whether the motherboard fan is spinning or not without opening the CPU case?

I'm referring to a fan that cools the processor chip, not the SMPS fan.

Is it possible to know that this fan is rotating or not without opening the CPU case?

## 125A 4P molded case circuit breaker in stock

Zhejiang Safesave Electrical Technology Co., Ltd. was developed by Shanghai Shuen Electrical Technology Co., Ltd. invested and built. Safesave focuses on high and low voltage electrical devices, complete electrical devices and industrial automation devices. Our products have been used for several key national projects such as the Shanghai World Expo, the Beijing Olympic Stadium, the South-to-North Water Division Project and Pudong International Airport. In the meantime, the factory was referred to as high technology company, science and technology company, software company, advanced quality management company, etc.
Our company works with partners from outstanding university research units such as the Academy for Mechanical Engineering, Electrical Engineering and Automation at the University of Shanghai, the Information and Technology Academy at the University of Fudan. After the restructuring, the plant will continue to research and manufacture high-end industrial automation equipment based on previous successes in the soft starter and frequency converter fields.
Brief history of the company's development
In 2000 – The first soft starter for thyristor motors was developed with independent research. This makes our company one of the earliest manufacturers of soft starters in China.
2003 – The factory was moved to Shanghai
In 2005 – The second generation of the intelligent soft starter and the frequency converter were certified as new and high-tech transformation services in Shanghai.
2006 – Identified as a high-tech company in Shanghai;
2007 – A new generation of vector frequency converters was manufactured on a large scale.
Relocation to the Caohejing Economic and Technological Development Zone in Shanghai
In 2008, batch products were applied to the Beijing Olympic Swimming Center and Shooting Center.
In 2010 the production was applied at the Shanghai World Expo.
Establish a cooperation relationship with the optoelectronic department of the University of Fudan and organize the research laboratory for photovoltaic inverters.
2014 – regrouping and relocation to the Songjiang National Economic and Technological Development Zone in Shanghai;
Build a strategic collaboration with the Chint Group and Delix Group and become the only official supplier of the inverting core components of EPS energy products for the two groups.
In 2015, SY9000 devices were successfully developed and put to the test.
In the meantime, the professional research team consisting of servo motor and servo controller has been organized.
2016 – A new setting-free, fast-starting, compact, easy-to-use soft starter called SJR3-N was successfully developed and put into test production.
Safesaves culture
Mission:
Create a greener world with our safe and energy-saving technology.
Vision:
To be a happy company that benefits human society.
Values:
Gratitude: Gratitude for God's grace, teamwork and customer trust.
Credibility: fruitful promise and successful action.
Commitment: persistence in the search for professional perfection.
Teamwork: A nurturing spirit of sharing, appreciation, collaboration and positive interaction.
Responsibility: Courage to take responsibility for every result without apology.
Passion: Full of energy and will to fight.
Learning: Consistent learning of professional skills in order to acquire efficient working skills.
Innovation: a force to change the step backwards and lead the market.
Share: growth in what we share.
The R&D team
1. Structure of the R&D center
Zhejiang Saikong Electrical Technology's research and development center consists of three sections: electronic design (systematic analysis and electronic circuits), structural design (heat dissipation design, configuration design) and measurement and verification (simulation and analysis, test and verification).
The research and development center has an experienced research and development team that works closely with the scientific research departments of the Institute of Mechanical and Electrical Engineering and Automation at the University of Shanghai, the Institute of Science and Technology and the Department of Information Technology at the University of Fudan.
With years of effort, Saikong has developed more than 100 models from 10 product lines through our outstanding talents and technologies.
2. Business area & successes in recent years.
The design of the research and development center mainly covers two areas: power electronics – energy saving and emission reduction. The main products include medium-low voltage soft starters, medium-low voltage drives, AC servo drives, servo motors, etc.
From 2013 to 2016, the research and development center successfully developed the intelligent soft starter type SST with integrated bypass, the intelligent soft starter series SJR3 and the intelligent online soft starter type 5000 with integrated bypass, SN-100G, series, SY9000 series of open loop vector inverters, G5 series of closed loop vector inverters, SN-200G series of closed loop vector inverters, waterproof inverter type, uninterruptible EPS power supply, permanent magnet synchronous motor and much more more than 100 models from 10 product lines. In the meantime, we have completed the corresponding CAPP system for computer-aided process planning, solid product database and process documents etc. for each product line.
The center has now applied for over twenty technical patents, including 4 invention patents, 14 patents for new utility models, 6 structural patents and 3 software copyright patents. By the end of 2016, 3 of our new invention patents had been registered and must be approved.
In recent years, led by a trend towards miniaturization, intelligence, networking and a job in product development, a number of new high-tech products have been developed in succession, including the intelligent soft starter type SST and the intelligent online soft type 5000 starter, SN -200G series of closed-loop vector inverters that have significantly increased the popularity and reputation of our company in this field. In addition to the increasing use of our products in the areas of manufacture, elevator, lifting, machine tools, printing and packaging, textile and chemical fibers, construction, metallurgy, mining, subway, etc. Saikong makes an important contribution to automatic control and energy supply. Saving and reducing emissions for our country with our advanced and reliable products.
3. Investments in our R&D center.
In order to improve the competence in the business field and the creativity for the sustainable development of our company, Saikong attaches great importance to the scientific research capacity and continues to increase the investment and strength of research for new products. R&D investments make up over 30% of the total budget, and the R&D crew accounts for 24.6% of the total workforce.
4. Brief introduction of the most important employees in the R&D center
The research and development team is led by Professor Zhao, the chief engineer who has been active in the field of power electronics for many years and who is involved in the research and development of a new generation of frequency inverters, soft starters, servo drives and servo motors. A full set of solutions, including offer selection, structural design, hardware design, software design, testing, quality guarantee, is delivered by our key research staff with an average of over 8 years of industry experience.
The center now has 25 employees, most of whom studied at major universities specializing in telecommunications and electrical machines. Among them are two professors for advanced engineers, 8 senior engineers and 14 engineers. In the meantime, as consultants, we are also hiring industry-renowned experts for inverters / construction / technology.
Leading Core Engineers Position Letter Introduction
Zhao EngineerTechnical Director / Chief Engineer Born 1972, 45 years old, Eng. Zhao works with the Electric Machinery Institute at the University of Shanghai as a supervisor for bachelor, master, and doctor students. He has long been involved in the design and development of hardware and software that are relevant to electronic inversion technology in the performance area and are integrated into the skills of project management and systemic analysis and design, having worked in several large companies as successive technological leaders or chief engineer and has developed more than 100 new models from 10 product lines of inverters, soft starters, servo drives and solar inverters, Eng. Zhao now has a very good reputation in the industry.
Engineer LiProject Engineer / System Utility Engineer Born in 1961 at the age of 56 with a bachelor's degree in industrial automation. Closely. Li is a pioneer in developing low voltage soft starters in China. As the earliest developer of low voltage soft starters in China, he led the development of the first generation of soft starters in China and achieved success.
Engineer Wang Hardware Engineer Born in 1978 at the age of 38 with a master's degree in electronic information technology. Closely. Wang has been researching and developing frequency converters for many years and has insightful insights into SMPS and inverter drives.
Engineer YiSoftware Engineer Born in 1979 at the age of 37 with a master's degree. Eng has long been involved in compiling software. Yi is very familiar with all types of software coding tools and has good work skills and industrial experience.
Zhu Hardware Engineer Born 1981, 35, with a bachelor's degree, a degree from Hefei Industrial University with a focus on engineering automation. Expert in systemic adjustments, technical identification, Eng. Zhu has insightful views in the areas of electronic circuitry, data acquisition and fault analysis.
5. Decent experimental environment.
To ensure the reliability of the developed products, the center set up two well-equipped, high-standard laboratories on an area of ​​500 square meters. One is used to test regular features and performance. The other is used to perform performance tests under extreme circumstances.
Despite the high costs, we bought complete devices to enable the experimental process from the simulation of the spot environment through the acquisition of technical data to digitized, visualized and traceable data processing and technology analysis. Every sample product is no longer a sample, but a device with practical application, and every data is no longer laboratory data, but highly simulated point data. In this way, we generally guarantee the data accuracy on site and the full-time reliability of the products.
List of the most important experimental devices in the R&D center
NO.Equipment / InstrumentFunction
1Standard equipment and devices:
Voltage source (constant voltage, adjustable), current source (constant current, adjustable), signal source (adjustable), standard resistance, standard capacitance, standard inductance etc. To ensure the accuracy of all devices and test data.
2Test devices for regular data:
Voltage meter, ammeter, multimeter, clamp meter, megger, small signal RMS ammeter, DC generator, oscilloscope, LCR bridge, regular data for general voltage, current, resistance, capacitance, inductance and signal waveform tests
3A variety of test devices for special parameters:
Power analyzer, spectrum analyzer, power analyzer, heat zone imager, temperature management instrument, tachometer, flow meter, pressure gauge, compensation machine etc. For testing special parameter data and the data collected under certain circumstances, wind speed, flow, pressure, rotational speed, strength of the magnetic field, balance, coil rolls, wire diameter and Power factor analysis, frequency spectrum analysis.
4 A variety of special test devices:
NC high pressure machine, shock generator, pulse group generator etc. For testing data parameters for special projects such as high voltage protection, creepage distance, electrical play, EMC interference, lightning resistance etc.
5 A variety of devices that simulate the field work environment:
NC high temperature chamber （0-300 ° C）, NC low temperature chamber （0- minus 150 ° C）, automatic ON / OFF experiment system, dust test box, acid / salt spray test box, shaft for pulling the load system (0) -1000A, Alternating current), vibration test system (1-200 kg), drop test devices etc. For testing the performance and data of spare parts or complete devices that work under extreme circumstances. To ensure that the products work in all regions in high regions reliability.
6 Various reliability test devices:
Automatic ON / OFF aging room, impact devices for high and low temperature cycles, high temperature aging chamber with load, anti-interference test room etc. For testing the reliability, stability, consistency, life of the device and other parameters of the components or the entire machine.
6. R&D orientation in the future
In addition to the development of society, technical progress and the revolutionary changes in the areas of domestic industrial automation control, energy saving and emission reduction, our research and development center is constantly refreshing perception and optimizing the products. Based on the goal of achieving miniaturization, multifunction, digitization, networking, specialization and modularization, we believe that the new products introduced by our research and development center will dominate the industry in the near future.
7. Strict management system and practical working style
"Not the best, just better"
This is the attitude of work and the aspiration of our research and development center.
"Committed to basic work, down-to-earth to try the best of everything."
This is the basic requirement of our own R&D members.
In the R&D center, the design work is processed in modular, pluralistic and step-by-step procedures, and the management weighs up responsibility, data and performance. The center attaches great importance to coordination between departments and managers and emphasizes the work efficiency of the entire team.
The center has clear goals and ideas for every project. To complete the project, the center takes over quantitative management. The specific division of labor is distributed among each person and the knot time is determined daily, so that the entire team becomes a strong, cohesive and centripetal force that works like a sophisticated engine to achieve a common performance goal through all orderly, tense and intense parts achieve enthusiastic work.
FAQ
Q1: Are you a manufacturer or a trading company?
A1: We are a manufacturer.
Q2: Can I get some samples?
A2: Yes, a sample order is available for quality checks and market tests. After we receive the sample fee, the samples will be delivered within 7-15 days.
Q3: Can you do the design for us?
A3: Yes. We have a professional design team. Just tell us your ideas and we will help you implement your ideas. Send us high-resolution images, your logo and your text and tell us how you would like to arrange them. We will send you finished files for confirmation.
Q4: What about the delivery time?
A4: This depends on the quantity and the season in which you place the order. The production usually takes about 7-15 days.
Q5: What are your delivery terms?
A5: We accept EXW, FOB, CFR, CIF etc. You can choose the one that is the most convenient or cost effective for you.
Q6: What are your warranty terms?
A6: We offer 1 year warranty. 125A 4P molded case circuit breaker in stock
Website: http: //www.skpowertech.com/
website2: http: //www.iiinvert.com/

## Algorithms – What is the worst case big-o time complexity for this code?

I had a quiz in my class and didn't do it well. I want to find out if anyone can explain what I did wrong here – our professor is overwhelmed with office hours when we went online, so I thought I would post here.

``````def functionC(L):
for i in range(len(L)):
if L(i) == i:
v = L.pop(i)
L.insert(i, 2*v)
return
``````

I gave the following answer:

The above function is O (n) because the for loop grows with the size of
L. The pop and insert functions are both constant.

The word time is crossed out, but there is no other explanation for why I got 6/10 for the question. What did I do wrong and why?

Here is a picture of the question and my answer to prove that the quiz has already been rated and returned.

## Discrete Mathematics – Construct the best case study for quick sorting with n = 15

So the question is to create a best case example for Quick Sort with 15 elements n = 15. Hopefully someone can give me a second opinion on whether this is the best case for this quick sort implementation.

The way the algo works for this exercise is that the pivot is always the last element.

As you will see in the picture, we have a (j). (j) is first in the first place. If the value at this position is less than the pivot point, it is moved to the next element (what actually happens is that it changes with the element itself, but since the element is in the same position, nothing has happened). If the value at (j) is greater than pivot, (j) remains where it is waiting for the next element that is smaller than pivot, then (j) and this element changes.

Finally, the pivot point changes position with the j element.

You may be wondering why we are still thinking about when p (starting element) == q (last element), but this is exactly what this exercise is like: (G (1,1), G (3,3),. ..) In this case we still call the function, but do nothing.

Note teacher gave was: The best case has to do with the least number of exchanges in a partition compared to the Pivot M.

My idea was to construct it from the bottom up and make sure that both sides of the tree are always the same, to avoid a situation when the fulcrum does not go to the center but stays on the side (aka list is almost sorted and we have a tree that is distorted to one side)

Many thanks for your help!

## mysql – Which is faster in this context between PHP switch case or database query

I have an online PHP / MySQL based Bible search app. There are currently only 5 book versions.

I am now asked to add more than 130 Bible versions. I think if this will affect performance.

The options I am considering are as follows.

OPTION 1::
Encode the different book names and use the PHP Shift key to specify the book to display. This is my current setup and this works well for 5 languages ​​that are currently added in my app. I did it because the database I get has only one book number column and no book name.

If the selected language is African, the following code checks the book number and applies the name accordingly (66 Bible books).

``````case "101": \$book ="101"; \$bookword = ("GENESIS" . ' ' . strval(\$chapter_id) . ':' . strval(\$verse_id)); break;
case "102": \$book ="102"; \$bookword = ("EXODUS" . ' ' . strval(\$chapter_id) . ':' . strval(\$verse_id)); break;
case "103": \$book ="103"; \$bookword = ("LIVITIKUS" . ' ' . strval(\$chapter_id) . ':' . strval(\$verse_id)); break;
...
case "166": \$book ="166"; \$bookword = ("OPENBARING" . ' ' . strval(\$chapter_id) . ':' . strval(\$verse_id)); break;
``````

This is done every time the user changes the language selection via the pulldown menu

OPTION 2::
Add a column `bookname` In each table (each table is a Bible version), this means an additional 31,000 entries for each book. In this way, the book name is already included in the query result. in the Option 1After the query, only the book number is available. I need to use the PHP switch to add the book name.

Will there be a significant difference between the two in terms of performance?

## EH-conjecture (special case)

Is this special case of the Elliot-Halberstam conjecture known?
To the $$gcd (1, q) = 1$$.
$$displaystyle sum_ {q leq x ^ {1- epsilon}} left | pi (x; q, 1) – frac { pi (x)} { varphi (q)} right | leq frac {Cx} { log ^ A (x)}$$

## Wallet – Use case for multiple entries in a single transaction

Is there a way to determine if a pair or more Bitcoin addresses belong to the same wallet based on a pair of addresses being used as input for a single transaction?

No.

Assuming that all of the inputs to a transaction come from the same wallet, are often referred to as "common heuristics for having inputs". However, it is possible to create transactions with input from different wallets. Therefore, there is no way to use this heuristic with 100% accuracy. In many cases it can work, but in many cases it will fail.

Can I check whether the address pair input is not part of a larger transaction or fund draw transaction, for example from a blockchain explorer?

No, the transaction data that is sent to the network intentionally does not contain any information about which software / method was used to create the transaction. In some cases, "transaction fingerprint" can be used to make an assumption about this, but again, at best, this is a guess, false alarms can also be easily created.

In which case would multiple entries within a single transaction belong to different purses in addition to enhancement transaction and fundraw transaction?

Some examples:

• Coinjoin transactions (e.g. wasabi wallet, join market)
• Lightning network channels (2of2 multisig)
• Other multisig purses (many possible situations)
• Payjoin transactions (similar to coinjoins, but not many working implementations afaik)
• etc