• 한국화재소방학회논문지
• /
• 제15권4호
• /
• pp.57-63
• /
• 2001

최근 지하공동구내의 화재가 자주 발생, 도시의 기능이 마비되는 등 국민생활을 위협하고 있으며, 막대한 재산 및 인명피해를 초래하고 있다. 지하공동구 화재로 인한 조기진압은 소방법의 연소방지설비 기준에 적용하였을 경우 화재진압시 많은 문제가 있다고 판단된다. 지하공동구의 연소방지설비 중에는 여러 방식을 적용할 수 있으나, 본 연구에서는 물을 이용한 방식 중에 국내 및 소방법에서 적용되지 않고 있는 워터 미스트(water mist)방식에 대해서 연구하고 그 설치 방안을 제시하고자 한다.

• 대한전자공학회논문지
• /
• 제11권6호
• /
• pp.16-24
• /
• 1974

본 논문은 종래의 NIC회로의 구성방법을 종합하여 일반화하는 방법으로써 파라미터 제어회로와 전압 또는 전류제어회로에 의한 NIC구성방법을 제시하였다. 그리고 FET에 의해 개방 및 단락안정형 NIC회로를 구성하고 회로해석에 의한 임피던스와 실험치를 비교하여 NIC특성을 확인하고 회로해석이 타당함을 검토 확인하였다. 또한 병렬 LC를 NIC와 직렬로 연결하여 발진상태를 실험으로 확인하고 NR에 의한 발진상태와 비교 검토하였다.

• 세라미스트
• /
• 제10권3호
• /
• pp.86-90
• /
• 2007

Novel photochromic oxide glasses are presented in this section. These glasses are based on phosphate formers containing both tungsten and antimony atoms. Exposure to visible continuous or pulsed laser beam results in an intense photochromic effect witch is shown to occur in the volume of the glass and results in a broad absorption band in the visible and near infrared. This effect was not identified to be related with a structural change and is assumed to be entirely electronic. A change in the absorption coefficient is observed in function of tungsten content, exposure time and increases with beam power. These glasses have been investigated regarding the possibility of holographic data storage using visible lasers sources. Changes in both refractive index and the absorption coefficient were measured using a holographic setup. The modulation of the optical constants is reversible by heat treatment.

• 대한음성학회:학술대회논문집
• /
• 대한음성학회 2002년도 11월 학술대회지
• /
• pp.175-178
• /
• 2002

Most existing telephone networks transmit narrowband speech witch has been bandlimited below 4 kHz. Compared with wideband speech up to 8 kHz, narrowband speech shows reduced intelligibility and a muffled quality. Bandwidth extension is a technique to generate wideband speech by reconstructing 4-8 kHz highband speech without any additional information. This paper presents experimental results of the bandwidth extension adopted for 4800 bps CELP speech coder. In this experiment, we examine various methods for reconstruction of wideband spectrum and excitation signal, compare and analyze their performance by performing the subjective preference test and measuring the cepstral distortion.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 A
• /
• pp.148-150
• /
• 1996

This paper describes method of microstepping current control for linear pulse moor. The control method witch electrically subdivides 1 step of a LPM 125 micro step is realized using micro-step algorithm. The resolution of the system for microstepping is improved also by microstep control of driving current, which is followed by the increase of microstep subdivision coefficient, the precise position and velocity control of LPM can be realized and stabilization of the system is improved.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
• /
• pp.54-57
• /
• 2003

A new non linear, mean value, instantaneous following control technique to design half bridge converter is proposed in witch control principle uses characteristic that reset time of analog integrator is inverse proportion In input voltage. It is Important characteristic that compensation and follow-up control time are same with switching frequency. Is completed in one cycle that base control frequency. Have excellence characteristic that follow in order instruction value exactly stationary state as well as transient state. Half bridge converter that apply this control principle can know that have stabilize and excellence characteristic. This technique is verified through an experiment, and know that experiment result and theory agree well.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2002년도 춘계학술대회 논문집
• /
• pp.190-198
• /
• 2002

In switched reluctance motor(SRM) drive, it is necessary to synchronize the stator phase excitation with the rotor position. Therefore the rotor position information is an essential. Usually optical encoders or resolvers are used to provide the rotor position information. These sensors are expensive and are not suitable for high speed operation. In general, the accuracy of the switching angles is dependent upon the resolution of the encoder and the sampling period of the microprocessor. But the region of high speed, switching angles are fluctuated back and forth from the preset values, witch are cause by the sampling period of the microprocessor. Therefore, the low cost linear encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper It is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate for the practical low cost SRM drive.

• 대한한방내과학회지
• /
• 제17권1호
• /
• pp.243-257
• /
• 1996

Sangphisan, sangphisan with Cortex Mori Cortex Lycii, Semen Lepidh were administrated into rats and then they were injected by Paraquat. The results are as follows 1. After 72 hours following the injection of paraquat, the survival rate of rats increased Sangphisan, Sangphisan with Cortex Mori Cortex Lycii Group. 2. Respirayory rates of rats witch survived 72 hours later significantly decreased in sangphisan, sangphisan with Semen Lepidh. 3. Lung weights of rats which survived for 72 hours later significantly decreased in Sangphisan, Sangphisan with Cortex Mori Cortex Lycii and mild decreased in Sangphisan with Semen Lepidh. 4. After the injection of paraquat, a lung tissue showed severe hemorrhage, edema and some broken aibeoli and Sangphisan, sangphisan with Cortex Mori Cortex Lycii, Sangphisan with Semen Lepidh recovered significantly.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
• /
• pp.1229-1234
• /
• 2001

The bottom slab of Inchon LNG in-ground #213 tank is designed as a massive structure witch has a large depth and section. The purpose of this study is to determine the optimum mix design having good workability and low hydration heat for bottom slab concrete and to control the actual concrete quality in site. For this purpose, we select the optimum mix design used ternary blended cement(furnace slag cement＋fly ash) and design factors. As test results of actual application, we have finish placing the bottom slab concrete of 23,180㎥ during 68hours with good success and obtain the good quality of fresh and hardened concrete including slump, air contents, no-segregation, compressive strength and low hydration heat in actual data. All test results are satisfied with our specifications for bottom slab concrete and we cut costs as the use of ternary blended cement and the reduction of placing hours.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2000년도 전력전자학술대회 논문집
• /
• pp.628-631
• /
• 2000

A new control method for precision robust speed control of a PMSM(Permanent Magnet Synchronous Motor) using load torque observer is presented. With this system we can obtain more reliable eye moving singal(nystagmus) Until now rotating chair system which is called 2D-optokinetic stimulator is used to make dizzincess. However an inclined rotating chair system witch is 3D-optokinetic stimulator is needed to obtain the precise dizziness data. This 3D-optokinetic sitimulator include unbalanced load aused by unbalanced center of mass. For this case new compensation method is considered to obtain robust speed control using load torque observer. To reduce the effect of this disturbance we can use dead-beat observer which has high gain. The application of the load torque observer is published in [1] for position control. A problem of using speed information such as amplifying effect of noise is reduce by moving average process. The experimental results are depicted in this paper to show the effect of this proposed algorithm.