• Journal of Power Electronics
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• 제4권3호
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• pp.169-179
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• 2004

This paper presents the steady-state analysis of the three-phase self-excited induction generator (SEIG). The three-phase SEIG with a squirrel cage rotor is driven by a variable-speed prime mover (VSPM) or a constant-speed prime mover (CSPM) such as a wind turbine or a micro gas turbine. Furthermore, a PI closed-loop feedback voltage regulation scheme of the three-phase SEIG driven by a VSPM on the basis of the static VAR compensator (SVC) is designed and evaluated for the stand-alone AC and DC power applications. The simulation and experimental results prove the practical effectiveness of the additional SVC with the PI controller-based feedback loop in terms of its fast responses and high performances

• Journal of Power Electronics
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• 제4권2호
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• pp.65-76
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• 2004

In this paper, the steady-state analysis of the three-phase self-excited induction generator (SEIG) driven by a variable-speed prime mover (VSPM) such as a wind turbine is presented. The steady-state torque-speed characteristics of the VSPM are considered with the three-phase SEIG equivalent circuit for evaluating the operating performances due to the inductive load variations. Furthermore, a PI closed-loop feedback voltage regulation scheme based on the static VAR compensator (SVC) for the three-phase SEIG driven by the VSPM is designed and considered for the wind power generation conditioner. The simulation and experimental results prove the practical effectiveness of the additional SVC with the PI controller-based feedback loop in terms of fast response and high performances.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권3호
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• pp.139-146
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• 2003

In this paper, the steady-state operating performance analysis for the three-phase squirrel cage rotor self-excited induction generator (SEIG) driven by a variable-speed prime mover (VSPM) in addition to a constant-speed prime mover (CSPM) is presented on the basis of an effective algorithm based on its frequency-domain equivalent circuit. The operating characteristics of the three-phase SEIG coupled by a VSPM and/or a CSPM are evaluated on line processing under the condition of the electrical passive load parameters variations with simple and efficient computation processing procedure in unregulated voltage control loop scheme. A three-phase SEIG prototype setup with a VSPM as well as a CSPM is implemented for the small-scale clean renewable and alternative energy utilizations. The experimental operating characteristic results are illustrated and give good agreements with the simulation ones.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권3호
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• pp.108-113
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• 2004

This paper presents methods to improve performance of the power supply system in a NASA deep space explorer. In the Stirling engine driven reciprocating Brushless DC (BLDC) generator, the accurate position information of the prime mover is important to diagnose the performance of the engine and prevent distortion of the output power. Since sensors to detect the position are fragile and unreliable, and conventional sensorless techniques have drawbacks in the low speed region, a novel sensorless position detection technique for the prime mover has been proposed and verified. Another major issue of the generator for the spacecraft is power density maximization. The mass of the power system is important to the mass of the satellite. Therefore, the components of the spacecraft should be lightweight. Conventional rectification methods cannot achieve the maximum power possible due to non-optimal current waveforms. The optimal current waveform for maximizing power density and minimizing machine size and weight in a nonsinusoidal power supply system has been derived, incorporated in a control system, and verified by simulation work.

• 한국의사학회지
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• 제22권2호
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• pp.15-22
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• 2009

In this thesis, the emphasis is laid especially on the culture & structure of Huizhou Province, China as the prime mover of the specifically-regional Huizhou $X{\bar{i}}n^{\prime}{\bar{a}}n$ medicine. Huizhou was the home town & stronghold of Neo-coufucian masters Cheng-Zhu (Cheng brothers and Zhu-hsi)". The tradition of the region as "The arts province" resulted in the flourishing trend of nurturing prominent Confucian-doctors. The remarkable all round activities of Huizhou Merchants (新安商人 $X{\bar{i}}n^{\prime}{\bar{a}}nsh{\bar{a}}ngr{\acute{e}}n$), as the reigning power merchant at the period were the second mover of the Zeitgeist. Their nation-wide network all over China made it possible to gain valuable inlormation and access to news including the field of medicine in time. Some merchants actually have "abandoned their own jobs to become doctors of medicine". This Confucian-Merchant culture was one of intrinsic characteristics of Huizhou region, inducing "Pragmatic Scholarship". With the enlargement of the population of Confucian-tumed doctors and improvement of the societal status of doctors, the resultant occupational triad of local Confucian govemment officials, local $X{\bar{i}}n^{\prime}{\bar{a}}nsh{\bar{a}}ngr{\acute{e}}n$ merchants, and local doctors was established after the Middle-Ming Dynasty. Ultimately, the two prime movers of the concomitant development of medicine in the Province Huizhou in this study are concluded to be the synergy effects of the Neo-Confucian tradition and economic power of the prevalent Huizhou Merchants ($X{\bar{i}}n^{\prime}{\bar{a}}nsh{\bar{a}}ngr{\acute{e}}n$).

• 동력기계공학회지
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• 제15권5호
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• pp.16-21
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• 2011

The large scale decisive battle will be gradually reduced on the sea in the future and surface combatant ship installed advanced weapon units as well as propulsion system will be continuously increased. The high level of military technology leads to appear state-of-the-art weapon system using high power energy. As a results, fossil fuel powered main prime mover as diesel engine and gas turbine which are composed of mechanical propulsion system should be decreased from combatant ship in the near future. The new building naval combatant ship with the latest technology has electric based propulsion method of the hybrid type combined with mechanical and electrical drive. U.S. and Royal Navy, especially, select the integrated fully electric based propulsion system for the next generation combat ship and play an important roll for developing them. In this context, this paper was focused on the deduction of implications through analyzing the combatant ship propulsion system using diesel and gas turbine engine which are promoted on the worldwide.

• 한국전문물리치료학회지
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• 제10권2호
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• pp.11-22
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• 2003

The purpose of this study was to analyze the effects of three different pelvic tilts on a sit-to-stand (STS) and to suggest a new assessment approach based on biomechanical analysis. The three difrent pelvic tilts were: (1) comfortable pelvic tilt sit-to-stand (CPT STS), (2) posterior pelvic tilt sit-to-stand (PPT STS) and (3) anterior pelvic tilt sit-to-stand (APT STS). To determine the onset time of muscle contraction surface electrodes were applied to the rectus femoris muscle (RF), vastus lateralis muscle (VL), biceps femoris muscle (BF), tibialis anterior muscle (TA), gastrocnemius muscle (GCM), and soleus muscle (SOL). The ICC was used for functional linkage analysis. The findings of this study were as follows. First, significant differences were found in kinematic variables and in muscle activation pattern among the three activities. Second, the results of functional integrated analysis revealed that recruited muscle activation patterns changed when the thigh-off was viewed as a reference point. Third, there were independent functional units between the thigh-off and the VL and between the thigh-off and the RF in the functional linkage analysis. The VL and RF acted as prime mover muscles, and more postural adjustment muscle recruitment was required as the demand of postural muscle control increased (PPT STS, APT STS, and CPT STS in order). In conclusion, the findings of this study suggest the following evaluative and therapeutic approach for STS activity. APT STS can be introduced for movement efficiency and functional advantage when abnormal STS is treated. However, excessive APT would change the muscle activation patterns of BF and SOL and require additional postural muscle control to cause abnormal control patterns.

• 한국운동역학회지
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• 제19권3호
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• pp.557-566
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• 2009

본 연구에서 KPGA소속 프로골퍼 5명, KLPGA소속 프로골퍼 5명 총 10명을 대상으로 골프 드라이브 스윙시 내측광근, 외측광근, 전경골근, 비복근의 근전도 분석을 통하여 운동역학적 요인을 비교분석하였으며, 그 결과 다음과 같은 결론을 얻었다. 성별에 따른 근 활동전위 차이는 어드레스부터 백스윙탑까지 구간에서 남성의 오른쪽 비복근이 가장 높게 나타났고, 백스윙탑에서 임팩트까지 구간에서 여성의 오른쪽 전경골근이 가장 높게 나타났으며, 모든 구간과 국면에서 남성의 경우 왼쪽 하지근이 주동근이었고, 여성의 경우 오른쪽 하지근이 주동근으로 나타났으며, 통계적으로 유의한 차이가 있는 것으로 나타났다. 남자의 경우 백스윙탑에서 임팩트 구간까지 체중을 이동시키면서 왼쪽 전경골근이 주동근으로 활동하는 것으로 판단되며, 여성의 경우 오른쪽 무릎을 왼쪽 무릎 쪽으로 밀어주는 동작에서 오른쪽 외측광근과 전경골근이 주동근으로 나타났다. 따라서 남성의 경우 왼쪽 외측광근과 전경골근을, 여성의 경우 오른쪽 외측광근과 전경골근을 발달시킬 수 있는 트레이닝을 수행한다면 비거리와 방향성을 향상시킬 수 있을 것으로 판단된다.

• KIEE International Transactions on Power Engineering
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• 제3A권1호
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• pp.27-34
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• 2003

In this paper, the power conditioner composed of the stand-alone single-phase squirrel cage rotor type self-excited induction generator (SEIG) driven by prime movers such as a wind turbine and a micro gas turbine (MGT) is presented by using the steady-state circuit analysis based on the two nodal admittance approaches using the per-unit frequency in addition to a new state variable defined by the per-unit slip frequency along with its performance evaluations for the stand-alone energy utilizations. The stande-alone single-phase SEIG operating performances in unregulated voltage control loop are then evaluated on line under the conditions of the speed change transients of the prime mover and the stand-alone electrical passive load power variations with the simple theoretical analysis and the efficient computation processing procedures described in the part I of this paper. In addition, a feasuible PI controlled feedback closed-loop voltage regulation scheme of the stande-alone single-phase SEIG is designed on the basis of the static VAR compensate. (SVC) and discussed in experiment for the promising stand-alone power conditioner. The experimental operating performance results are illustrated and give good agreements with the simulation ones. The simulation and experimental results of the stand-alone single-phase SEIG with the simple SVC controller for its stabilized voltage regulation prove the practical effectiveness of the additional SVC control loop scheme including the PI controller with fast response characteristics and steady-sate performance improvements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.29-32
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• 1987

Hydro turbine, steam turbine and their generators can be described by one general model. To realize the turbine simulator, personal computer, D.C. motor and three phase thyristor converter have been used. In the experiments for the improvement of power system stability, that is, steady state, dynamic and transient stability, the characteristics of turbine simulator proposed by this paper have shown that of real prime mover.