• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.4
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• pp.418-425
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• 1998

In this paper. determination method of turn-off angle in the SRM drives is proposed to maintain the high torque at a any turn-on angle, which is realized by using selHuning control method, During the sampling time. a number of P pulses from encoder are checked by using one-chip microprocessor. and compared with pre-checked a number of pulses A After calculating difference between two data, the turn-off angle moves forward or backward direction by the self-tuning m method, As repeating such process, the optimal turn-off angle is determined and the maximum torque is maintained T Though experiments, it is observed that motor speed is almost maintained if turn-off angle is adjusted automatically by s selHuning method when turn-ηn angle is changed.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.231-240
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• 2001

U-turn and P-turn as well as left-turn restriction exist in real traffic network. the optimal route should be selected for considering these using shortest path algorithms. But, the traditional algorithms have some limitations to use for considering there. The objective of this paper is to modify Dijkstra algorithm in order to find the optimal path in real traffic network. The continuous three nodes are used to check turn-restrictions and exclude these from and optimal path. A virtual connection is used to consider U-turn and P-turn.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.241-249
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• 2001

The objective of this paper is to develop the optimal path algorithm for dynamic route guidance system in advanced traveler information system (ATIS). The travel time is forecasted in each path between network nodes. Floyd-Warshall algorithm is used to find the optimal route based on this forecasted travel time in dynamic traffic network. This algorithm is modified to apply the real traffic network that has left-turn restriction, U-turn, and P-turn. A big value is assigned to one of arcs in turn restriction and a virtual node is used to consider U-turn and P-turn for Floyd-Warshall algorithm.

• Journal of Industrial Technology
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• v.22 no.A
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• pp.73-82
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• 2002

It is difficult to find the shortest paths using existing algorithms (Dijkstra, Floyd-Warshall algorithm, and etc) in high complex and large size real traffic networks The objective of this paper is to develop an evolution program to find the multiple shortest paths within reasonable time in these networks including turn-restrictions, U-turns, and etc.

• Journal of IKEEE
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• v.11 no.4
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• pp.158-164
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• 2007

In this study, three types of a novel Trench IGBTs(Insulated Gate Bipolar Transistor) are proposed. The first structure has P-collector which is isolated by $SiO_2$ layer to enhance anode-injection-efficiency and enable the device to have a low on-state voltage drop(Von). And the second structure has convex P-base region between both gates. This structure may be effective to distributes electric-field crowded to gate edge. So this structure can have higher breakdown voltage(BV) than conventional trench-type IGBT(TIGBT). The process and device simulation results show improved on-state, breakdown and switching characteristics in each structure. The first one was presented lower on state voltage drop(2.1V) than that of conventional one(2.4V). Also, second structurehas higher breakdown voltage(1220V) and faster turn off time(9ns) than that of conventional structure. Finally, the last one of the proposed structure has combined the two structure (the first one and second one). This structure has superior electric characteristics than conventional structure about forward voltage drop and blocking capability, turnoff characteristics.

• Journal of IKEEE
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• v.12 no.2
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• pp.110-117
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• 2008

This paper presents a new Insulated Gate Bipolar Transistor(IGBT) based on Non Punch Through(NPT) IGBT structure for power switching device. The proposed structure has adding N+ beside the P-base region of the conventional IGBT structure. The added n+ diffusion of the proposed device ensure device has faster turn-off time and lower forward conduction loss than the conventional IGBT structure. But, added n+ region can reduce th breakdown voltage and latching current density of the proposed device due to its high doping concentration. This problems can be overcome by using diverter on the right side of the device. In the simulation results, turn-off time of the proposed device is 0.3us and the on-state voltage drop is 3V. The results show that the proposed device has superior characteristic than conventional structure.

• KLA journal
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• v.16 no.8
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• pp.13-16
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• 1975

본 기사는 Josephine Riss Fang 교원가 Chinese Libraries Carry Out Chairman Mao's Dictum : 'Serve the Reople'이란 표제로 Wilson Library Bulletin, vol. 49(June 1975), p.774-749에 기고한 것을 우리 말로 옮긴 것이다. Fang교원는 오스트리아 태생으로 현재 미국 보스턴에 있는 시몬즈대학의 도서관학교원로 재직중에 있다.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.13-20
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• 2014

The natural convection heat transfers of a helical coil in a duct were measured experimentally varying the inclination. To achieve high Rayleigh number, mass transfer experiments instead of heat transfer experiments were performed based upon the analogy. The $Ra_D$ was fixed to $4.55{\times}10^6$. The turn numbers were 1~10. the pitch to diameter ratio were 1.3~5, and the inclination of the helical coil $0^{\circ}{\sim}90^{\circ}$. The measured $Nu_D$ for a single turn of the helical coil was very close to that from McAdams heat transfer correlation for a horizontal cylinder. The heat transfers of the helical coil were varied by the pith, number of turns, and duct height in a complex manner showing the velocity, chimney, and pre-heating effects. The results of the study contributes to the phenomenological analyses of the natural convection heat transfer of a compact heat exchanger.

• Proceedings of the CALSEC Conference
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• 2001.08a
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• pp.457-465
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• 2001

■ 필요성 1. 교통 혼잡으로 인한 물류비 상승으로 국가 경쟁력 약화 2. 기존 최단경로 알고리즘(Dijkstra, Floyd-Warshall 등)의 한계 3. 대규모 네트워크(NP-hard문제)→정보 사용자가 제시하는 시간 내에 정보를 제공 필요 4. 교통 제약(회전금지, U턴, U턴 금지, P-턴) → 실제 교통 상황과 순환 노드 고려가 필요 ■목적 1. 교통제약을 포함한 대규모 교통네트워크에서 실시간 교통정보를 바탕으로 제한된 시간 내에 차별화 된 다수 최적경로 산출 함 2. 유전자알고리즘(GA)을 적용한 동적경로안내시스템 개발(중략)

• Journal of the Korean Data and Information Science Society
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• v.23 no.5
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• pp.993-1003
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• 2012

The purpose of this study was to estimate the determinants of victory and defeat through analyzing records of Korean men pro-basketball. Statistical models of victory and defeat were established by collecting present basketball records (2010-2011, 2011-2012 season). Korea Basketball League (KBL) informs records of every pro-basketball game data. The six offence variables (2P%, 3P%, FT%, OR, AS, TO), and the four defense variables (DR, ST, GD, BS) were used in this study. PASW program was used for logistic regression and Answer Tree program was used for the decision tree. All significance levels were set at .05. Major results were as follows. In the logistic regression, 2P%, 3P%, and TO were three offense variables significantly affecting victory and defeat, and DR, ST, and BS were three significant defense variables. Offensive variables 2P%, 3P%, TO, and AS are used in constructing the decision tree. The highest percentage of victory was 80.85% when 2P% was in 51%-58%, 3P% was more than 31 percent, and TO was less than 11 times. In the decision tree of the defence variables, the highest percentage of victory was 94.12% when DR was more than 24, ST was more than six, and BS was more than two times.