• Progress in Superconductivity and Cryogenics
• /
• v.8 no.2
• /
• pp.29-32
• /
• 2006

An advanced superconducting fault current limiter (SFCL) using $high-T_c$ superconducting (HTS) wire has been developed. The SFCL has a non-inductively wound magnet for reducing loss in normal state. Two types of non-inductively wound magnets, the solenoid type and the pancake type, were designed and manufactured by using Bi-2223 wire in this research. Short-circuit tests of the magnets were performed in sub-cooled $LN_2$ cooling system of 65 K. The magnets are thermally more stable and have a higher critical current in 65 K sub-cooled $LN_2$ cooling system than in 77 K saturated one. Because the resistivity of matrix at 65 K is lower than the resistivity at 77 K, the magnets generate a small resistance to reduce the fault current when the quench occurs. The magnets could limit the fault current to low current level with such a small resistance. The current limiting characteristic of the magnets was analyzed from the test result. The solenoid type was wound in parallel to make it non-inductive. The pancake type was also connected in parallel to be compared with the solenoid type in the same condition. The solenoid type was found to have a good thermal stability compared with the pancake type. It also had as large resistance as the pancake type to limit the fault current in sub-cooled $LN_2$ cooling system.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.6
• /
• pp.1141-1149
• /
• 1992

This paper presents a robust centralized control scheme for a magnetic bearing system which supports a rigid rotor at both shaft ends in the radial direction. The negative stiffness element and the inductive force associated with bearing magnetic field are considered in the dynamic model of the system. For this model, the controllability and observability are examined, and then a robust control theory is applied to design two types of multi-input multi-output servocontrollers. A general servocompensator is embedded in the first one and a centralized PID controller is suggested as a second one. By simulation study, the performance of two types of servocontrollers are compared in the aspects of disturbance rejection, reference tracking and the robustness limit.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.4
• /
• pp.897-902
• /
• 2018

The purpose of this study is to develop a bioinformatic diagnostic system that diagnoses the patient 's health condition by using the output waveform generated by applying the impulse voltage of 13Hz to 7 body parts based on DFM (Diagnose Fure Funktionelle Medizine) theory. It is expected that the data acquired by the diagnostic system will be served as a device for diagnosing the status of the body organ as well as the mesenchymal tissue through inductive reasoning based on artificial intelligence. In this paper, we will limit the system to acquire and manage bio-signals.

• Progress in Superconductivity and Cryogenics
• /
• v.12 no.1
• /
• pp.37-41
• /
• 2010

To limit fault current in a power system, superconducting fault current limiters (SFCLs) using high temperature superconducting (HTS) coils have been developed by many research groups so far. Non-inductive winding of HTS coils used for SFCLs can be classified into solenoid winding and pancake winding. Each of winding is expected to have different quench and recovery characteristics because the structure of solenoid winding differs from pancake winding's. Therefore it is important to the SFCLs application to investigate characteristics of each winding. In this paper, we deal with quench and recovery characteristics of four kinds of winding : solenoid winding, pancake winding without spacers, and with spacers of 2 and 4 mm thickness. In order to obtain quench and recovery parameters of coils, short circuit tests were performed in liquid nitrogen.

• The Korean Journal of Air & Space Law and Policy
• /
• v.22 no.2
• /
• pp.155-175
• /
• 2007

As intellectual terror threats increase, we feel the limit in coping with those threats and the things we do are placing traditional X-ray machines & ETD and increasing aviation security staffs. In fact, even if air transportation system is the fast and most efficient transportation methods, it is true that there are many inconveniences to endure due to terror threats. In the name of security, even if we make a lot of efforts and time to screen both good-natured passengers, baggage, cargo and suspicious passengers, it is impossible to screen perfectly and it is not an efficient methods. Therefore, we introduce profiling system that reduce the effort to screen good-natured passengers but focus on screening dangerous passengers and baggages. Profiling system strengthens aviation security, using the concept "Selection & Concentration". Israel started to introduce manual profiling system in aviation security, which is interviewing suspicious passengers and it has been used in crime investigation since 1960. And it has been upgraded and diversified to CAPPS(Computer Assisted Passenger Screening Program) and SPOT(Screening Passenger by Observation). So, this theses is to study on the concept & kind of profiling and profiling methods adopted in airlines. Also it presents the method of introduction of profiling system in Korea and the necessity of making law on it.

• 한국체육학회지인문사회과학편
• /
• v.54 no.3
• /
• pp.31-43
• /
• 2015

The purpose of this study was to find out the dance sports athlete's factor that presents performance problems and performance enhancing for competitions. To achieve purpose of study carried out open-ended question and structural inquiry of succession in the dance sports athlete of 25 people, the open-ended questions data were examined through inductive content analysis procedure, conducted preliminary investigation to 100 people. Preliminary investigation and main survey were verified to the dance sports athlete of 137 people through exploratory factor analysis, and confirmatory factor analysis was conducted. On the basis of the results, the conclusions were drawn as follows; First, hinders factors to athletic performance is discord with partner, condition, contest environment, limit of physical strength, limit of economic strength. Second, the measurement scale of dance sports athlete's performance enhancing to competition with 23 items which are consisted of 7 main factors. The determination factors of dance sports athlete performance were partnership, ability to invest, spiritual factors, training factors, ability of physical factors, the leader, environment of competition.

• Journal of the Korea Furniture Society
• /
• v.21 no.6
• /
• pp.439-448
• /
• 2010

Furniture world which is closely associated with human life had been constantly developed, but traditional furniture disappeared after modernization almost. The reason lies rather in the importance of the diversity of Western-style furniture pursuing convenience and shapes, than in change of life style meanwhile. The diversity however reached the limit and it made a new advanced role of not only furniture, also design sector in general necessary, and as solution to solve this problem the immaterial value based on Eastern philosophy/mental was suggested in architecture and all around design sector overall as well. It means that the immaterial point which traditional furniture involved should be focused now and furthermore it's emotional and mental value which is more natural and has close relation with human being accordingly could be judged rightly. The reason why traditional furniture had been used since long time is the immaterial tendency which is well harmonized with the surrounding environment rather than the function. To verify this, the present study aimed to analyze not only the basic, also additional function of traditional furniture used in Hanok (traditional Koran-style house) by the inductive method for investigating the additional effects which users felt. Such immaterial role offers the user more convenience besides the original function of furniture and this made it available that furniture dominates the space. As good examples of such roles it was investigated that traditional furniture played meaningful roles like extensional serviceability, variable space, formation & movement of space, expression of grade of rank. That allowed that this study suggested the sustainable design and also the direction of development of interactive function of furniture through the expected effect having been showed in the modern space where the immaterial role of traditional furniture was applied to and the related cases.