• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.9
• /
• pp.789-798
• /
• 2005

This paper is a numerical study concerning how the interactions between a pair of the vortices effect flow field and heat transfer. The flow field (common flow down) behind a vortex generator is modeled by the information that is available from studies on a half-delta winglet. Also, the energy equation and the Reynolds-averaged Wavier-Stokes equation for three-dimensional turbulent flows, together with a two-layer turbulence model to resolve the near-wall flow, are solved by the method of AF-ADI. The present results predict that the boundary layer is thinned in the regions where the secondary flow is directed toward the wall and thickened where it Is directed away from the wall. Although some discrepancies are observed near the center of the vortex core, the overall performance of the computational model is found to be satisfactory.

• Proceedings of the KIEE Conference
• /
• 2000.07d
• /
• pp.2971-2973
• /
• 2000

In this paper, we proposed the implementation of multiple access serial communications with improved transmission control. For serial communications. RS232 protocol is used and the transmitting data and is merged to form data channel. Multiple host access is configures by using the common data channel and ground channel. 8bit data transfer with variable frame size is transferred by using the 16bit host ID. Packet is composed of HEADER, receiver ID. variable length data frame, TAIL and CRC informations. Multiple hosts are allowed to transfer packet with the other hosts through the common communication channel. Byte-stuffing is used to differentiate the transfer rate of PC is performed.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10b
• /
• pp.1811-1816
• /
• 1991

In this paper we present how the deviation bound, which is a synchronic variable, can be used for checking liveness in Petri nets. Also, the deviation bound will be applied to detect or avoid deadlock situations and to characterize concurrency against sequential behaviors in automated manufacturing systems. In the current stage, we restrict the applicable domain of these methods to the Petri net structure that can be synthesized by combining common transitions or common places or common paths of Live-and-Bounded circuits.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.350-353
• /
• 2011

전 세계적으로 기후변화로 인한 자연재해가 빈번하게 발생함에 따라 수자원 분야에서 또한 환경의 변화에 대한 정확한 예측이 더욱 요구되고 있다. 국내에서도 이를 위하여 다양한 방법을 통하여 연구가 이루어지고 있으나 본 연구에서 사용된 Common Land Model (CLM)은 국내에서의 실질적인 적용이 아직 부족하다. 이 모형은 Soil-Vegetation-Atmosphere Transfer 모형 중 대표적 모델로 Land Surface Model (LSM), Biosphere-Atmosphere Transfer Scheme (BATS), Chinese Academy of Sciences Institute of Atmospheric Physics LSM의 세 모형이 결합되어 발전하였다. CLM의 강제입력자료로는 위성, 지면모형 등을 기반으로 만들어진 자료를 제공하는 Korea Land Data Assimilation Systme (KLDAS; 한반도지표자료동화체계)의 격자화 된 자료를 사용하여 모형에 강제시켰다. KLDAS는 기존의 Land Data Assimilation System (LDAS)에서 발전한 형태로 동아시아 지역을 대상으로 자료를 제공하고 있으며, 본 연구에서는 이 자료를 사용하여 국내 전반에 걸쳐 격자에 대한 수문 기상학적 인자를 산출하였다.

• Journal of Power Electronics
• /
• v.16 no.3
• /
• pp.1236-1243
• /
• 2016

This paper presents the analysis and design of an active electromagnetic interference (EMI) filter (AEF) for the common-mode (CM) noise reduction of switching power converters. The features of the several types of AEFs are discussed and compared in terms of implementation. The feed-forward AEF with a voltage-sensing and voltage-cancellation (VSVC) structure is implemented for an LLC resonant converter to replace a multiple-stage passive EMI filter and thereby reduce CM noise. The characteristics and performance of the VSVC-type AEF are investigated through theoretical and experimental works.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.05a
• /
• pp.321-323
• /
• 2009

When power failure occurs at multi-housing complex, auxiliary generator or emergency generator starts to provide power to households. This power is connected to emergency power ELB(Earth Leakage Breaker) at home distribution panel board and supplies power only for emergency light in living room but for heating system, refrigerator and other inevitable apparatuses that are in need of uninterruptible power. Since those domestic appliance are fed from common power line, they are inoperable during power failure. Our research is to resolve this problem by developing compatible relay-drive common/emergency-power ATS (automatic transfer switch) for home distribution panel board. In case of power failure, it transfers automatically and commences to provide power from emergency generator. Through this, Consumers can reach satisfaction where common power loads operate without any problem under both ordinary and power failure condition.

• Proceedings of the Korean Society for Bioinformatics Conference
• /
• 2005.09a
• /
• pp.388-391
• /
• 2005

The Protein Structural and Functional Conservation need a common language for data definition. With the help of common language provided by Protein Ontology the high level of sequence and functional conservation can be extended to all organisms with the likelihood that proteins that carry out core biological processes will again be probable orthologues. The structural and functional conservation in these proteins presents both opportunities and challenges. The main opportunity lies in the possibility of automated transfer of protein data annotations from experimentally traceable model organisms to a less traceable organism based on protein sequence similarity. Such information can be used to improve human health or agriculture. The challenge lies in using a common language to transfer protein data annotations among different species of organisms. First step in achieving this huge challenge is producing a structured, precisely defined common vocabulary using Protein Ontology. The Protein Ontology described in this paper covers the sequence, structure and biological roles of Protein Complexes in any organism.

• Journal of Advanced Marine Engineering and Technology
• /
• v.26 no.1
• /
• pp.23-29
• /
• 2002

Solid-liquid phase change (i.e. melting or solidification) occurs in a number of situations of practical interest. Some common examples include the melting of edible oil, metallurgical process such as casting and welding, and materials science applications such as crystal growth. Therefore, due to the practical importance of the subject, there have been a large number of experimental and numerical studies of problems involving phase change during the past few decades. Also, this study presented the effective way to enhance phase change heat transfer.

• International Journal of Air-Conditioning and Refrigeration
• /
• v.14 no.4
• /
• pp.131-137
• /
• 2006

The absorber in which heat and mass transfer phenomena occur simultaneously is one of the most critical components in the absorption system. It has the most significant influence on the performance and the size of the absorption system. During the absorption process, heat and mass transfer resistances exist in both liquid and vapor regions, so that the heat transfer mode should be carefully selected to reduce them. The objective of this paper is to review the previous papers analysing mathematical models of simultaneous heat and mass transfer phenomena during the absorption process. The most conventional working fluids ($H_2O$LiBr and $NH_3/H_2O$) are considered and the most common absorption modes (falling film and bubble mode) are dealt with in this review.

• Proceedings of the KSME Conference
• /
• 2001.11b
• /
• pp.235-240
• /
• 2001

This study presents experimental work on phase change heat transfer, in order to increase heat transfer rate, ultrasonic vibrations were introduced. Solid-liquid phase change occurs in a number of situations of practical interest. This study reveal that ultrasonic vibrations accompany the effects like agitation, acoustic streaming, cavitation, and oscillating fluid motion. Such effects are a prime mechanism in the overall melting process when ultrasonic vibrations are applied. Some common examples include the melting of edible oil, metallurgical process such as casting and welding, and materials science applications such as crystal growth. Therefore, this study presented the effective way to enhance phase change heat transfer.