• 한국정보통신학회논문지
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• 제9권5호
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• pp.1111-1116
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• 2005

초고속 인터넷의 보급, 디지털 정보장비의 확산 및 생활 패턴의 변화에 따라 홈 네트워크의 필요성이 점차 확대되고 있다. 이에 따라 본 연구에서는 홈 네트워크화를 위해서 8051 MCU, Hardware TCP/IP를 이용하여 임베디드 이더넷 모듈을 설계, 개발하였다. 타겟 머신에 간단한 웹 서버를 구축하고 이를 이용한 원격제어 프로그램을 포팅하여 원격지에서도 인터넷으로 가전기기를 제어할 수 있도록 하였다. 본 연구에서 개발한 모듈을 이용하므로 저가격으로 홈 오토메이션을 구현할 수 있으리라 생각한다.

• 한국항해학회지
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• 제18권3호
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• pp.19-30
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• 1994

By use of the recent tropical cyclones' data in the Northwest Pacific Ocean, the occurrence frequency and region of typhoon as well as the features of the monthly mean track were analyzed. As the result of this study, (1) mean occurrence frequency of typhoon per year is 27.5, and 68% of total typhoons were formed in July to October and shown the highest frequency in August. (2) The ave-rage duration of typhoons is 8.5 days, and super typhoon which maximum sustained surface wind speeds is more than 130 knots occurs most frequently in October and November. (3) The highest frequency ap-pears around the Caroline, Mariana and Marshall Islands, and in wintertime, typhoon occurs in lower lati-tude comparing with those in summertime. (4) The typhoon track depends upon the distribution of pres-sure system and steering current in neighbouring areas. The mean track of typhoon can be classified into three types such as westward-moving type, northward-moving type and abnormally moving type. The west-ward-moving typhoons make landfall on the southern China by way of the South China Sea in June and July, on mid-part of China in August and September, and on Indo-china Peninsula in October and Novem-ber. The northward-moving typhoons approximately move on north~northwestward track to $20~30^{\circ}N$ from the occurrence region, then recurve to the East Sea through Korean Peninsula and Kyushu Island in June and July, to the Noth Pacific Ocean along the Japanese Islands in August and September and to the North Pacific Ocean through the seas far south off the Japan in October and November.

• 한국추진공학회지
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• 제12권3호
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• pp.16-23
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• 2008

30 톤급 실물형 연소기의 산화제 매니폴드에서의 유동 균일성 문제를 파악하기 위하여 유동해석을 수행하였다. 분사기의 모사를 위하여 다공성 매질로 가정하고, 다공성도 (porosity)를 조절하여 분사기 차압을 모사하였다. 수직 및 수평 분리막에서의 구멍의 직경, 입구 포트의 형상에 따른 유동의 균일성 정도를 파악하고, 개선된 설계 수정안을 제시하였다. 수직 및 수평 분리막 구명의 형태와 배치 수정을 통하여 유량 균일성을 향상시킬 수 있음을 확인하였다.

• 한국자동차공학회논문집
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• 제14권2호
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• pp.121-126
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• 2006

A gasoline-fueled stratified charge compression ignition (SCCI) engine with both direct fuel injection and intake temperature and compression ratio was examined. The fuel was injected directly by using the high temperature resulting from heating intake port. With this injection strategy, the SCCI combustion region was expanded dramatically without any increase in NOx emissions which were seen in the case of compression stroke injection. Injection timing during the intake temperature was found to be an important parameter that affects the SCCI region width. The effect of mixture stratification and the effect of fuel reformation can be utilized to reduce the required intake temperature for suitable SCCI combustion under each set of engine speed and compression ratio conditions.

• 대한의용생체공학회:의공학회지
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• 제9권1호
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• pp.93-100
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• 1988

The Auto Regressive Parameter Estimation and Pattern Classification of EKG Signal for Automatic Diagnosis. This paper presents the results from pattern discriminant analysis of an AR (auto regressive) model parameter group, which represents the HRV (heart rate variability) that is being considered as time series data. HRV data was extracted using the correct R-point of the EKG wave that was A/D converted from the I/O port both by hardware and software functions. Data number (N) and optimal (P), which were used for analysis, were determined by using Burg's maximum entropy method and Akaike's Information Criteria test. The representative values were extracted from the distribution of the results. In turn, these values were used as the index for determining the range o( pattern discriminant analysis. By carrying out pattern discriminant analysis, the performance of clustering was checked, creating the text pattern, where the clustering was optimum. The analysis results showed first that the HRV data were considered sufficient to ensure the stationarity of the data; next, that the patern discrimimant analysis was able to discriminate even though the optimal order of each syndrome was dissimilar.

• 수산해양기술연구
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• 제44권2호
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• pp.148-156
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• 2008

In this study it will be discussed how to solve the problem of discomfort from rolling motion on the fishing boats. Most discomfort is caused by the short cycle of rolling due to the light weight of the boats. The light weight is due to the FRP material which dries a boat. A way to improve the feeling of boarding by using fish hold was researched. The experiment was done on experimental fishing boat made by FRP in Jeju. An existing fish hold was designed and manufactured through the rolling test and that was used for a marine experiment. The rolling condition of the U-tank boat ideally designed was compared to that of an existing fishing boat using the same conditions. The experiments were carried out two times on the stop engine in the outward Sehwa fishing port, which the experimental data had analysed for effects of rolling reduction to compare the U - tank with the of exiting fish hold. The results were confirmed that the U-boat tank in the roll period and GoM were more safe than the existing fish hold and the average amplitude and significant of rolling angles were decreased relatively.

• 물과 미래
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• 제21권1호
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• pp.87-94
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• 1988

금강하구의 비선형(비대칭) 조석을 관측결과로부터 조사하였는데 하구에서의 강한 해저마찰에 의한 에너지소산에도 불구하고 M4 분조는 확폭되어 강한 조석비대칭현상을 야기시킨다. 관측된 조석비대칭은 긴 지속시간의 낙조보다 상대적으로 짧은 지속시간의 강한 장조류속이 토사의 이동을 증대시키는 데 이 현상이 하구의 매몰을 유발시켜 M2 내역에 분포된 사주의 형성요인인 것으로 추정된다. M2 분조와 M4 분조에 관련된 첨두해안응력의 분포를 2차원조류 수치모델에 의해 산정했는데 결과는 현존의 조류퇴적체계중 소류사의 분포는 하구둑 건설로 인해 외항접근수로와 하구둑 사류부에 변화를 가져올 것으로 초기추정된다.

• 한국재료학회지
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• 제25권11호
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• pp.598-601
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• 2015

Using reverse micelle processing, $ZnAl_2O_4$ nanopowders were synthesized from a mixed precursor(consisting of $Zn(NO_3)_2$ and $Al(NO_3)_3$). The $ZnAl_2O_4$ was prepared by mixing the aqueous solution at a molar ratio of Zn : Al = 1 : 2. The average size and distribution of the synthesized powders with heat treatment at $600^{\circ}C$ for 2 h were in the range of 10-20 nm and narrow, respectively. The average size of the synthesized powders increased with increasing water to surfactant molar ratio. The XRD diffraction patterns show that the phase of $ZnAl_2O_4$ was spinel(JCPDS No. 05-0669). The synthesized and calcined powders were characterized using a thermogravimetric - differential scanning calorimeter(TG-DSC), X-ray diffraction analysis (XRD), and high resolution transmission electron microscopy(HRTEM). The effects of the synthesis parameter, such as the molar ratio of water to surfactant, are discussed.

• 한국해안해양공학회지
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• 제1권1호
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• pp.31-43
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• 1989

사강하구의 비선형 조석 및 이에 관련된 퇴적동력학을 조석수치모형을 이용하여 조사하였다. 조석모형은 하구조문대의 노출양상 및 이차원 하구모형과 일차원 감조하천모형을 동적접합시키는 데 역점을 두었다. 모형의 결과는 하구의 강한 봉제소산에도 불구하고 M$_4$분조는 상당한 크기로 산정되었으며 이에 의한 조석비선형은 강한 장조와 상대적으로 약하나 대적시간이 긴 노조로서 제시된 바 하구사주형성의 한 요인이 된다. 또한 모형으로부터 산정된 해저최대봉제응력의 공간적인 분포는 사강하구둑 건설로 인해 군산항접 근수로 및 하구둑 하류부에 큰 퇴적변화가 야기될 수 있음을 제시하고 있다.

• International Journal of Automotive Technology
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• 제7권6호
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• pp.675-680
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• 2006

In the direct injected gasoline engine, atomized spray is desired to achieve efficient mixture formation needed to good engine performance because the injection process leaves little time for the evaporation of fuels. Therefore, substantial understanding of global spray structure and quantitative characteristics of spray are decisive technology to optimize combustion system of a GDI engine. The combustion and emission characteristics of gasoline-fueled stratified-charge compression ignition(SCCI) engine according to intake temperature and compression ratio was examined. The fuel was injected directly to the cylinder under the high temperature condition resulting from heating the intake port. With this injection strategy, the SCCI combustion region was expanded dramatically without any increase in NOx emissions, which were seen in the case of compression stroke injection. Injection timing during the intake temperature was found to be an important parameter that affects the SCCI region width. The mixture stratification and the fuel reformation can be utilized to reduce the required intake temperature for suitable SCCI combustion under each set of engine speed and compression ratio conditions.