• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.2
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• pp.127-135
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• 2020

The purpose of this paper is to classify individual startups by growth stage based on data-based quantitative criteria. This is to provide a basis for systematic support for government startups based on accurate statistics on the startup growth process. This startups were the TIPS (Tech Incubator Program for Startup) support company, which used a relatively reliable startup. We found seed money to complete MVP (Minimum Viable Product) within 1.5 years after establishment, verified PMF (Product-Market Fit) within 1 year, attracted Series A investment within 2.5 years after establishment, and successfully commercialized it. It attracted Series B investment for stable growth within 1.5 years (Series B investment within 4 years from start-up). The results of the study, the division of government programs that support stage-based startup commercialization, that is, within three years and within seven years of establishment, is significant to date. Three directions are suggested for future research. First, develop indicators for monitoring startup growth stages. Second, it continuously updates the annual changes and tracks the growth stages of individual startups. Third, we discover the successful growth law of technology-based startups by applying in-depth case analysis of successful startups to the model.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.6
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• pp.602-609
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• 2011

This paper proposes a simple initial rotor position estimation method to obtain a stable startup performance for back EMF-based sensorless control. The proposed estimation method is achieved at standstill by using the current response to difference between each of the stator winding inductance. This initial rotor position estimation method can be easily implemented to control algorithm without any other external devices. The proposed algorithm is also not affected by motor parameter. The validity of the proposed method is demonstrated by experimental result.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.6
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• pp.1-8
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• 2014

The government has established a foundation activation measures across a total of 10 times to expanse job creation, promote new growth engines and enhance youth entrepreneurship for trying to spread socially. In order to improve startup activation policies and excavation, it is necessary to supplement the gaps going to construct a stable infrastructure through periodic status research on their occupational sense and entrepreneurship awareness. Since 2012, the government's has been surveyed to address the current understanding of the occupational sense and entrepreneurship awareness of population characteristics. Until 2013 only the youth were surveyed, recently from 2014 expanded its range to the public. This study laid the foundation for a more comprehensive set of analysis through which to learn and understand the differences between the status of each group for entrepreneurship awareness by utilizing survey data from the government. And this study was obtained from a survey of university students and the general public. A total of 3000 people nationwide survey was conducted about the entrepreneurship environment for start-ups and entrepreneurship awareness and success factors for a month. The University students survey result were classified according to the area, school and gender. And The general public survey was classified according to the area, the age and gender. Each response result indicates a significant difference between the students and the general public did not appear. But through this survey, This study would contribute the establishment of the national startup infrastructure.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.210-211
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• 2011

이 논문은 역기전력을 기반으로 한 센서리스 제어 시에 향상 된 초기기동 성능을 위한 간단한 초기 회전자 위치추정 방법을 제시하였다. 제시된 추정방법은 전동기가 정지상태에서 전류와 인덕턴스의 반비례관계를 이용하여 회전자의 돌극성에 의한 고정자 각 권선의 인덕턴스의 변화로 생기게 되는 전류의 대소관계를 비교하여 초기 회전자 위치를 추정한다. 이 초기 회전자 위치추정 방법은 역기전력을 기반으로 한 센서리스 제어와 함께 구현되기가 쉽고 성공적인 초기기동으로 역회전이나 기동에 실패하지 않게 하며, 기존의 다른 인덕턴스에 의한 전류포화를 이용한 방법에 비해 빠르고 쉽다는 것이 장점이다. 또 다른 장점으로 이 방법은 외부적인 장치가 필요가 없고 모터의 변수들에 영향을 받지 않는다. 실험으로서 제시한 초기 회전자 위치추정의 방법을 증명하였다.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.1
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• pp.1-6
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• 2014

A new sensorless control strategy for brushless DC (BLDC) motors is proposed in this paper. This technique builds a rotor position-related flux function, which is independent of the speed. By observing the flux function, the information of rotor position and commutation can be obtained. As the function is not speed-related, this control process can be used in a wider range of speed and improves the motor's performance during startup. An experimental test bad based on TMS320F2812 has been built, and the experimental result indicates that the motor achieves a smooth starting-up and stable phase commutation with the proposed control strategy.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1885-1886
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• 2006

The thermal energy from nuclear fission is transferred to the steam generator which is a kind of a large heat exchanger. After the feedwater is injected into the steam generator and absorbs the thermal energy, it is converted into the steam. This steam goes into the turbine. The balance between the generated energy and the consumed energy is required for the nuclear power plant to be stable. For the purpose of which, the feed water, a parameter for energy transfer, should be controlled in stability. Usually, the nuclear power plants are operated in base load in the view of power system for the stability of fission system. Therefore, though there will be almost no unbalance, there can be some instability from unbalance in case of startup/shutdown or disturbance. In this case, the controllability of feedwater pump is very important for the quick recover of stability.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.5
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• pp.77-83
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• 2020

The operating characteristics of a main oxidizer shut-off valve have been examined by life-cycle tests in which the valve operates as many times as is required at room and cryogenic temperatures. It is shown that there is no significant change of the operating characteristics in the course of the life-cycle tests. The critical pressures and principal forces, which represent the operating characteristics, differ at each operating time by less than about 3%. These qualified operating characteristics of the valve are expected to play an indispensible role in the stable startup and shutdown of a liquid rocket engine.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.1959-1974
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• 2024

Nuclear energy plays a crucial role in energy supply in the 21st century, and more and more Nuclear Power Plants (NPPs) will be in operation to contribute to the development of human society. However, as a typical complex system engineering, the operation and development of NPPs require efficient and stable control methods to ensure the safety and efficiency of nuclear power generation. Reinforcement learning (RL) aims at learning optimal control policies via maximizing discounted long-term rewards. The reward-oriented learning paradigm has witnessed remarkable success in many complex systems, such as wind power systems, electric power systems, coal fire power plants, robotics, etc. In this work, we try to present a systematic review of the applications of RL on these complex systems, from which we believe NPPs can borrow experience and insights. We then conduct a block-by-block investigation on the application scenarios of specific tasks in NPPs and carried out algorithmic research for different situations such as power startup, collaborative control, and emergency handling. Moreover, we discuss the possibilities of further application of RL methods on NPPs and detail the challenges when applying RL methods on NPPs. We hope this work can boost the realization of intelligent NPPs, and contribute to more and more research on how to better integrate RL algorithms into NPPs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.795-804
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• 2009

An HSS(Home Subscriber Server) system requires a main-memory database on main-memory unit for the real-tine management of the subscriber information in the mobile communication service, in that the system controls not only basic data for handling calls of users, but also additional service data related to user authentication and operational data. Nonetheless, HSS-DBS system, requiring the reliability and stability, need more secure data store method and a back-up technique because the system have a long startup time and the big problem on the failures of main-memory. This paper proposes an efficient back-up replication technique, on the basis of enhancing the stability and performance of HSS system. The proposed shadowing back-up technique adopting the delayed recovery process, can help minimize the real-time back-up overloads by location registration, while the proposed backup replication method enables more stable system operations with replicating the data to remote server in real time.

• Journal of Advanced Technology Convergence
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• v.2 no.2
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• pp.1-8
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• 2023

Due to the recent long-term economic downturn, the number of non-store and mail-order sellers is increasing as prospective entrepreneurs are concentrated due to the phenomenon of non-store start-ups with low start-up costs. In particular, in addition to unemployed young people and housewives who lack funds, many office workers who wish to have a 'two-job' are jumping into the business. Therefore, in this paper, we have moved away from provider-oriented service platforms that are dependent on specific networks, operators, and service types. In addition, we plan to design a business integration support system that can provide B2B services in the promotional material industry that contributes to business support and profit generation of wholesale and retail non-store entrepreneurs through sharing and participation. The proposed system is judged to be a business integrated operation support system applying orchestration and service management technology and enterprise business partner management technology that can provide stable operation management service.