• 한국생물물리학회:학술대회논문집
• /
• 한국생물물리학회 1996년도 정기총회 및 학술발표회
• /
• pp.34-34
• /
• 1996

Previously we showed that $Ba^{2+}$ block of large conductance $Ca^{2+}$-activated $K^{+}$ (BK) channel was larger in the planar lipid bilayer formed with negatively-charged phosphatidylserine (PS) than neutral phosphatidylethanolamine (PE). In this work, have studied the blocking effect of two $K^{+}$ channel blockers with different mechanisms of action, $Ba^{2+}$ and tetraethylammonium (TEA), on BK channels of rat skeletal muscle. (omitted)itted)

• 한국콘텐츠학회논문지
• /
• 제7권6호
• /
• pp.99-106
• /
• 2007

본 연구는 다매체 다채널 시대를 맞아 국내 주요 5개 방송사의 뉴스 시청자는 어떤 유형의 사람들이며 그들은 어떤 이유에서 특정 채널의 뉴스를 선택하는지를 규명하고자 실시되었다. 이 연구는 4개의 TV 뉴스 콘텐츠의 채널 선택 유형(channel loyalty type, brief news type, central watcher type, peripheral watcher type)을 귀납적으로 측정, 채널 선택 유형에 따른 인구통계학적 특성과 채널 선택 특성 등을 밝히는데 목적이 있다. 연구 결과 'brief news' type이 가장 높은 비율을 차지해 생활 패턴의 변화와 뉴스시청 행위가 밀접한 관계가 있음을 알 수 있다. 또 뉴스 채널 선택 유형에 따라 성(性)과 연령, 직업 등 인구통계학적 특성이 나타났다. 아울러 방송사별로 시청자들의 채널 선택 유형에 나름대로 특징이 있는 것으로 분석됐다. 즉 KBS1은 'central watcher', MBC는 'channel loyalty', SBS는 'peripheral watcher', YTN은 'brief news' type이 특징적으로 나타났고 KBS2는 뚜렷한 특징이 없는 것으로 분석됐다.

• 대한교통학회지
• /
• 제28권1호
• /
• pp.77-86
• /
• 2010

최근 국내에서는 민간 분야뿐만 아니라 공공물류에의 활용을 위해 좀 더 신뢰성 있고 개선된 화물수요추정방법에 대한 관심이 높아지고 있다. 현재 화물수요분석의 기초자료로 활용되고 있는 지역 간 화물기종점통행량(OD)자료는 각 화물의 생산지와 소비지 사이의 이동과 전환관계가 복잡함에도 불구하고 출발지와 목적지 사이의 환적시설이나 물류시설을 노드로 구분하지 않고 각 존의 물동량에 포함시킴으로써 화물의 정확한 이동이나 전환관계를 파악하지 못하게 하는 한계점을 지니고 있다. 본 연구의 목적은 이러한 인식하에 개별 의사결정자인 기업에 의해 이동되는 화물의 물적인 흐름을 분석하기 위한 물적 유통경로 선택모형을 개발하는 것이다. 이는 개별회사의 의사결정에 있어 매우 거시적인 개념이며, 개별 의사결정자인 기업이 유통경로를 선택할 때 어떠한 요소를 고려하는지를 살펴 보고자하였다. 본 연구에서는 2007 화물유통경로조사의 내수화물자료를 중심으로 기초통계 분석을 수행하고 물적 유통경로 선택모형을 구축하였다. 또한 구축된 모형이 합리적인지 평가하기 위해 최종 모형에 대해 유통경로선택이론을 기초로 가설검증을 수행하고 적중률을 산출하였다. 선정된 최종모형의 가설 검증결과, 제조업체는 유통경로 선택시 도착지점의 시장특성, 업종 및 품목특성, 경로특성, 기업의 크기 및 경제력 등을 중요하게 고려하는 것으로 나타났다.

• 수산해양교육연구
• /
• 제25권3호
• /
• pp.733-742
• /
• 2013

The Korea has significant tidal current energy resources, but it is so hard to work underwater for tidal turbine installation. Therefore commercial diving work is very important for tidal current generator. Also, Jangjuk channel is vary famous as proper area to generate tidal current energy. Nevertheless, no one is studied about characteristics of commercial diving works with installation of tidal current generator. The purpose of this study is to introduce commercial diving with work types and investigate critical limits of diving working under the conditions, which are working only to minutes at slack tide during the neap tide. As the results, work types are five as like mooring installation, OMAS(Offshore Maintenance Access System), support structure installation, cable and turbine installation. Here, the original construction period is expected about 4 months, but the construction take 18 months to complete. The cause of extends construction period is insufficiency of researching tidal current conditions at the site and ignorance of slack tide which need to secure diving working time. Total diving working times are 110th during 18 months, the highest percentage of diving times is turbine installation about 43.6 %, and cable, mooring installation and support structure construction are 27.3 %, 15.5 %, 13.6 %, respectively. On the basis of this study, estimation of times of commercial diving is possible with work types of tidal current power, and has a significance as basic data to determining construction period.

• 대한의용생체공학회:의공학회지
• /
• 제29권4호
• /
• pp.295-301
• /
• 2008

A wireless 3 channel ECG monitoring system was developed so that it could monitor the health and movement state during subject's daily life. The developed system consists of a wireless biomedical signal acquisition device, a personal healthcare server, and a remote medical server. Three experiments were performed to evaluate the accuracy, reliability and operability, applicability during daily life of the developed device. First, ECG signals were measured using the developed device and commercial reference device during sitting and marking time and compared to verify the accuracy of R-R intervals. Second, the reliable data transmission to remote server was verified on two types of simulated emergency event using patient simulator. Third, during five types of motion in daily life, the accuracy of data transmission to remote server using CDMA network was verified on two types of event occurring. By acquiring and comparing subject's biomedical signal and motion signal, the accuracy, reliability and operability, applicability during daily life of the developed device were verified. In addition, PDA-phone based wireless system enabled subject to be monitored without any constraints. Therefore, the developed system is expected to be applicable for monitoring the aged and chronic diseased people and giving first-aid in emergency.

• Journal of Communications and Networks
• /
• 제7권3호
• /
• pp.313-324
• /
• 2005

The success of the IEEE 802.11 standard has prompted research into efficiency of the different medium access methods and their support for different traffic types. A modified version of the point coordination function (PCF) called modified PCF has been introduced as a way to improve the efficiency over the standard method. It has been shown through a simulation study and a mathematical analysis that channel utilization can be much improved compared to the standard, in case there is no so-called hidden station problem. However, under the hidden station problem, the efficiency of the modified PCF would obviously decrease. In this paper, some enhancements of the modified PCF are introduced. Firstly, we propose a retransmission process to allow frames involved in collisions to be retransmitted. Then, we propose a collision resolution mechanism to reduce the frame collision probability due to the hidden station problem. In addition, we propose a priority scheme to support prioritization for different traffic types such as interactive voice and video, and real-time data traffic in the modified PCF. To prevent the starvation of one low priority traffic, minimum transmission period is also guaranteed to each traffic type via an admission control algorithm. We study the performance of the modified PCF under the hidden station problem and the performance of the modified PCF with priority scheme through simulations. To illustrate the efficiency of the priority scheme, we therefore compare its simulation results with those of some standardized protocols: The distributed coordination function (DCF), the enhanced distributed channel access (EDCA), the PCF, and our previously proposed protocol: The modified PCF without priority scheme. The simulation results show that the increment of delay in the network due to the hidden station problem can be reduced using the proposed collision resolution mechanism. In addition, in a given scenario the modified PCF with priority scheme can provide better quality of service (QoS) support to different traffic types and also support a higher number of data stations than the previous proposals.

• 대한지리학회지
• /
• 제32권4호
• /
• pp.421-434
• /
• 1997

합류점에서 일어나는 하도의 조정양상과 그 변화에 영향을 미치는 요소를 조사히기 위하여 수리조건이 다른 두 하천을 합류시키는 수로실험을 실시했다. 하도횡단면의 크기와 형상은 각기 다른 요소의 지배를 받는다. 하도의 단면적과 유속이 주로 유량의 영향을 받는데 비하여 형태와 경사는 유량과 유송토사량의 상호관계에 의해 결정된다. 그 결과 합류점의 하도특성치 변화는 유량과 유송토사량의 상대적인 증가율에 따라 달라지는 유사농도의 변동상황에 의해 세 유형으로 구분된다. 합류점에서는 유슈의 수렴에 따른 유속의 급증현상으로 인하여 하도단면적과 하도경사는 예상보다 작은 변화를 보이므로 유사농도가 크게 증가하지 않는 경우에는 하도특성치 변화에 그 영향이 나타나기 어렵다.

• 한국습지학회지
• /
• 제19권4호
• /
• pp.484-490
• /
• 2017

복단면 형태를 이루는 직선하도 내 사행하는 저수로의 형태에 따른 흐름 특성을 파악하기 위해, 국내 대표적인 하도 형태를 상정해 실내 수리모형을 실시해서 3차원 수치모의의 유효성을 확인하고, 이를 바탕으로 다른 유형의 하도 형태에 대해서도 수치모의로 검토를 실시하였다. 본 연구결과, 수리모형 실험에서 관측한 수심별 유속값을 이용하여 수치모형의 검정을 수행한 결과, 수치모의 결과와 충분히 일치하는 것으로 확인하였다. 이를 토대로, 추가적인 저수로 형태 변화에 따른 유동장에 대해 분석한 바에 따르면, 선행 연구들에서 검토된 이차류 현상이 발생하였음을 확인한 한편, 고수부지 내 유수단면적 확대에 따라 최고유속분포 지점이 이동하는 현상을 확인할 수 있었다. 궁극적으로 저수로 폭 변화가 흐름에 영향을 끼쳐 궁극적으로 하천설계에 중요한 요소인 수충부의 위치와 그 영향 정도를 파악하는 것이 필요하다고 판단된다.

• 한국의류학회지
• /
• 제25권6호
• /
• pp.1122-1130
• /
• 2001

Recently the importance of distribution channel design has been focused on due to a turbulent environment. The channel design strategy involves the choice of an optimal channel arrangement including channel width, channel depth, the types of intermediaries to be used, and the specific responsibilities of each channel member. The purpose of this paper is to investigate changes of distribution intensity in the infant & children's wear brand from 1997 to 1999, when Korea has faced changes before and after IMF intervention that influenced the Korean economy greatly. Thus, this study provides channel managers with some guidelines for establishing and adjusting the infant & children's wear channel strategies. The data is collected by the Korean Fashion Brand Annual published by Apparel News Co., from 1997 to 1999. infant & children's wear brands are selected and analyzed with Pearson correlation. Statistic analysis has shown different results in the type of brands in terms of distribution intensity. The type of brands between infant's wear and those for children differ in price and launching period. In the case of infant's wear brands, the launching period and total sales should be considered in designing channel distributions, while for children's brands total sales are significant. As the price increases, children's wear brands are significantly linked to their distribution intensity only in certain times at the starting point of IMF intervention. IMF intervention do not seem to influence the distribution intensity of infant's wear brands much as it did children's wear brands. It seems that the infant's wear industry is more stable than the children s wear industry. As a result, the marketer who plans distribution intensity for the infant's and children's wear brands should consider total sales, the launching period and the price according to the type of brands he deals with.

• 상하수도학회지
• /
• 제18권4호
• /
• pp.500-507
• /
• 2004

This study was conducted to evaluate the equity of the flow distribution from rapid mixing basin to the flocculation basins. Also, several types of inlet structures of the open channel affecting the flow pattern and distribution trend were studied using Computational Fluid Dynamics (CFD) simulation. For investigating the factual phenomena in distribution channel, we selected a certain domestic water treatment plant with capacity of $361,000m^3/d$. From the measurements of flow discharge, it is investigated that this existing inlet geometry resulted in significant inequitable distribution. The both largest deviations in the basins and rows were over 10%. In order to reduce the these deviation, this study suggested installing a baffle against the influent, and showed the effectiveness which the largest deviation was less than 3%. Also, it was concluded that the existing design method of open channel could be improved by three-dimensional hydrodynamic analysis for optimizing the even flow.