• 한국항해항만학회지
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• 제45권3호
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• pp.148-154
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• 2021

컨테이너터미널 운영에서 안벽영역의 장비와 기술이 발전함에 따라 항만운영의 정체가 장치장으로 이전되었다. 따라서 장치장 관리가 터미널 운영 전반에 미치는 영향이 매우 커졌다. 이에 따라 컨테이너터미널 장치장 운영의 최적화를 위한 연구가 많이 수행되었으나 장래 장치장 점유율 변화 자체를 추정한 연구는 없는 실정이다. 본 연구는 부산항 신항을 대상으로 시간의 경과에 따른 확률의 변화를 설명하는 마코프 체인을 적용하여 부산항 신항 컨테이너 터미널의 장치장 점유율 수준에 대한 확률을 분석하였다. 분석결과 부산항 신항의 장치장 점유율은 향후에도 높은 수준을 유지할 확률이 큰 것으로 나타났다.

• 대한건축학회연합논문집
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• 제20권6호
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• pp.113-119
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• 2018

Occupancy-based heating control is effective in reducing heating energy by preventing unnecessary heating during unoccupied period. Various technologies on detecting human occupancy have been developed using complicated machine learning algorithm and stochastic methodologies. This study aims at deriving low-cost and simple algorithm of occupancy inference that can be implemented to residential buildings. The core concept of the algorithm is to combine the occupancy probabilities based on indoor CO2 concentration and PIR(passive infrared) signals. The probability was estimated by applying different levels of decrement ratio depending on CO2 concentration change rate and aggregated PIR signals. The developed algorithm was validated by comparing the inference results with the occupancy schedule in a real residential building. The results showed that the inference algorithm can achieve the accuracy of 75~99%, which would be successfully implemented to the control of residential heating systems.

• 한국실내디자인학회논문집
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• 제12호
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• pp.50-56
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• 1997

In the past thirty years, apartment house has been greatly developed and the housing supply has improved some degree. However, the fact is that interior space planning of apartment house still has a lot of problems. The purpose of this study is to research the change of interior room. The 160 examples of unit floor plan(40-85m2 i.e. 12.1py-25.7py) were selected and classified according to master bedroom type and living room area when was constructed by the city of Seoul and KNHC from 1970 to 1990. And then, the change of each area, size and ratio were analyzed and researched. The result of this research can be summarized as follows: 1. Size of unit floor plan was on the increase from 16.02py to 17.86py. 2. 2 bedroom type, master bedroom showed a rise of size and occupancy ratio. Living room grew larger than 1982-1991 for size and occupancy ratio. 3. 3 bedroom type, master bedroom was increased in size and occupancy ratio was reduced to 19.99%. Size of living room became broader than master bedroom and occupancy ratio(1972-1981) increased over 1982-1991. Through this analysis and research, this study is to provide the basic data for actural design process and to suggest future trend of apartment house.

• The Journal of Asian Finance, Economics and Business
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• 제9권4호
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• pp.315-324
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• 2022

The goal of this study is to understand better the relationship between hospital bed occupancy rate and cost rigidity as a proxy for the degree of hospital bed congestion, as well as the relationship between the risk of changes in hospital bed occupancy rate and congestion cost, targeting public hospitals. As public hospitals for analysis, we selected hospital projects from the Public Enterprises Survey Reports published by the Department of Public Enterprises, Ministry of Finance, and obtained unbalanced panel data consisting of 1,505 hospitals and 15 years, totaling 12,595 hospitals and years. The analysis revealed that the risk of changes in the bed occupancy rate increases the degree of cost rigidity and leads to a decrease in the variable cost ratio; furthermore, an increase in the bed occupancy rate decreases the degree of cost rigidity and leads to an increase in the variable cost ratio. These findings suggest that although public hospitals are taking managerial actions to avoid congestion costs, congestion costs resulting from higher bed occupancy rates have not been eliminated. The regression analysis results show that even if congestion costs arise as the occupancy rate increases, they are covered by the increase in revenue associated with the increase in the occupancy rate.

• 한국전자파학회논문지
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• 제7권4호
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• pp.279-287
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• 1996

주파수 점융율 데이터는 개별 주파수 채널의 실제 이용율에 대한 정보를 제공할 수 있다. 또한 스펙트럼의 예비 용량이 추정될 수 있도록 이들 주파수 대역들의 평균 이용율에 대한 정보를 제공한다. 그러한 추정치는 추가 배분 계획 및 스펙트럼 사용에 대한 새로운 기술의 영향을 평가하는 방법으로 사용될 수 있다. 본 논문에서는 국내에서 개발한 주파수 점유율 측정 시스템과 측정 방법을 제시한다. 그리고, 수도권 5개 지역의 전파감시 결과 데이터를 이용하여 주파수의 점유율을 시간대 및 지역별로 제시한다.

• 한국병원경영학회지
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• 제15권4호
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• pp.43-62
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• 2010

This study provides an evidence on the determinants of the profitability of university hospital by analyzing university hospital-level data set of hospital performance during the year 2007 (32 university hospitals in total). For the study, a multiple regression model is employed in which profitability index obtained from the DEA computations, operating margin to total asset and gross revenue are used as the dependent variables, and a number of hospital operating characteristics are chosen as the independent variables such as ownership type, location, bed size, period of establishment, bed occupancy rate, admission ratio of outpatients, patients per medical specialist, personnel cost per patient, liabilities to total assets, current ratio, fixed ratio, total asset turnover, medical assistance rate and public indicator. First, the results indicate that the bed occupancy rate and liabilities to total assets are positively and significantly associated with operating margin to total asset. Second, number of beds, the bed occupancy rate and number of patients per medical specialist are positively and significantly associated with operating margin to gross revenue. Third, the bed occupancy rate, number of patients per medical specialist, liabilities to total assets, total asset turnover are positively and significantly associated with profitability index revealed from DEA.

• 한국통신학회논문지
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• 제22권4호
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• pp.855-869
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• 1997

In this paper, we proposed two kids of dynamic priority control mechanisms controlling the cell service ratio in order to improve the QOS(Quality of Service). We also analyse theoretically the characteristics of cell loss probability and mean cell delay time by applying the proposed priority control mechanisms to ATM switch with output buffer. The proposed priority control mechanisms have the same principles of storing cells into buffer but the different principles of serving cells from buffer. The one is the control mechanism controlling the cell service ratio according to the relative cell occupancy ratio of buffer, the other is the control mechanism controlling the cell service ratio according to both the relative cell occupancy ratio of buffer and the average arrival rate. The two service classes of our concern are the delay sensitive class and the loss sensitive class. The analytical results show that the proposed control mechanisms are able to improve the QOS, the characteristics of cell loss probability and mean cell delay time, by selecting properly the relative cell occupancy ratio of buffer and the average arrival rate. conventional DLB algorithm does not support synchronous cells, but the proposed algorithm gives higher priority to synchronous cells. To reduce synchronous cell loss rate, the synchronous cell detector is used in the proposed algorithm. Synchronous cell detector detects synchronous cells, and passes them cells to the 2nd Leaky-Bucket. So it is similar to give higher priority to synchronous cells. In this paper, the proposed algorithm used audio/video traffic modeled by On/Off and Two-state MMPP, and simulated by SLAM II package. As simulation results, the proposed algorithm gets lower synchronous cell loss rate than the conventional DLB algorithms. The improved DLB algorithm for multimedia synchronization can be extended to any other cells which require higher priority.

• 한국통신학회논문지
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• 제23권9A호
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• pp.2249-2257
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• 1998

In this paper, we propose the enhanced priority control algorithm that adaptively controls the cell service ratio according to the relative cell occupancy ratio of buffer. The asynchronous transfer mode (ATM) provides the means to support various multimedia services in broadband networks. To support multimedia services, various data traffics of different priorities should be controlled effectively. And also it needs congestion control functions required in the netowrk to carry out the control operation. To accomplish this in a flexible and effective manner, priority classes for the different services ar ecommonly used. The proposed enhanced priority control mechanism have two service calsses of the delay sensitive class and the loss sensitive class. The simulation results show that te proposed control mechanism improves the QoS, the charateristics of cell loss probability and mean cell delay time, by selecting propeor relativ ecell occupancy ratio of buffer and the average arrival rate.

• 대한전자공학회논문지TC
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• 제41권10호
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• pp.69-77
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• 2004

본 논문에서는 ATM 망에서의 효율적인 트래픽 제어를 위하여 언어적인 규칙과 퍼지 추론부로 구성되는 퍼지 로직에서 퍼지 규칙을 생성하였다. 퍼지 규칙 내부에 포함된 제어 파라메터들은 주어진 성능 함수를 최소화하도록 학습된다. 즉, 전체 트래픽 도착율과 버퍼의 점유율에 따라 퍼지집합 이론을 통하여 추론한 후 그 비퍼지화값으로 접속된 트래픽에 대해 서버에서의 서비스율을 제어하도록 하였다. 또한, 생성된 퍼지 규칙의 타당성을 검증하기 위하여 MATLAB6.5에서와 온라인 빌드업으로 규칙에 대한 실험결과를 보인다. 그 결과, 전체 트래픽 도착율과 버퍼의 점유율에 따라 효율적으로 서버에서의 서비스율이 제어 됨을 확인하였다.

• 대한토목학회논문집
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• 제30권6D호
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• pp.569-575
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• 2010

재차인원의 파악은 HOV 차로 및 HOT 차로 정책의 효과 분석뿐만 아니라, 램프미터링, 공공주차장 운영 등 다양한 부분에 대한 핵심적 입력변수이다. 재차인원에 대한 조사 방법과 TCS (Toll Collection System) 자료를 이용한 O/D 구축방법은 개별적으로 기존 연구에서 많이 수행되어 왔지만, TCS 자료를 이용한 재차인원별 O/D 구축에 대한 연구는 전무한 실정이다. 본 연구는 재차인원 정보가 추가된 TCS 자료를 조사하여 수단별 O/D를 산출하는 과정을 자료조사부터 구축과정에 대한 제반 방법론으로 제시하였다. 특정 영업소(서울 영업소) 진출 방향에 대하여 특정일에 오전 첨두, 오후 비첨두, 오후 첨두, 심야 각 2시간씩 승용차, 버스, 트럭으로 구분된 차량에 대하여 재차인원 조사(노측 조사)를 실시한 후 톨부스, 차종, 도착시간을 기준으로 매칭과정을 거쳐 해당 날짜의 TCS 자료에 재차인원 정보를 추가하여 재차인원별 O/D를 구축하였다. 한 예로써 구축 결과 오전 첨두시 서울로 향하는 나홀로 차량이 약 60%에 이르는 것으로 나타났다. 이러한 방법론은 TCS 자료를 이용한 특정 O/D 구축 방법론과 연계할 경우, 전국 센트로이드간 재차인원별 O/D 산출도 가능할 것으로 판단되며 재차인원 정보를 요구하는 교통정책의 수립에 활용되어 질 수 있을 것으로 판단된다.