• 한국컴퓨터그래픽스학회논문지
• /
• 제14권1호
• /
• pp.27-33
• /
• 2008

모바일 시스템은 메모리, CPU 등의 자원이 기존 데스크탑 시스템 보다 상대적으로 많이 부족하고 정수형 연산처리만을 사용해야 하는 제약이 있다. 본 논문에서는 모바일 시스템의 특성에 적합한 새로운 모바일 3D 연결데이터 압축 기법을 소개 하고자 한다. 연결 데이터 압축 시 옥트리 구조와 메쉬 삼각화 특성을 활용하여 연결되는 점간의 거리에 기초한 새로운 압축 방법을 개발하였다. 또한, 압축 및 해제 시에 정수형 연산만을 사용하고 동적 메모리 할당을 최소화하였다. 실제 핸드폰에서 실시간 압축 해제된 3D 메쉬 테스트 자료도 소개하여 본 알고리즘의 실용성을 높이고자 한다.

• 한국환경과학회지
• /
• 제26권4호
• /
• pp.509-519
• /
• 2017

The study focuses on 32 environmental facilities in Incheon Metropolitan City, South Korea, categorizes them by sector: sewage treatment, wastewater treatment, incineration, landfill, water purification, and water supply. Their GHG reduction results are analyzed through quantitative and qualitative measures for 2012 to 2015. The study surveys and examines GHG reductions of the environmental facilities for two categories - facility operation and management. The findings are as follows: First, the GHG reduction rate, an emission-to-allocation ratio, from 2012 to 2015 is 89.67%. Second, GHG reductions coming from qualitative measures of facility management are even greater than those from quantitative measures of facility operation. Third, GHG reductions through facility operation are mostly attributable to overhauls, less use of facilities, resources recycling, process improvement rather than the betterment of fuels, facilities and energy efficiency. Fourth, higher reduction can be achieved by effective facility management, qualitative measures.

• 한국경영과학회지
• /
• 제24권3호
• /
• pp.63-72
• /
• 1999

Recent studies on the Constant Bit Rate and Variable Bit Rate transmissions have mainly focused on the frame by frame encoder rate control based on the quantization parameter. With the existing approaches it is difficult to guarantee a consistent video quality. Also, the rate control overhead is too high for the real-time video sources. In this paper, a channel rate allocation scheme based on the control period is proposed to transmit a real-time video, in which the control period is defined by a pre-specified number of frames or group of pictures. At each control period, video traffic information is collected to determine the channel rate at the next control period. The channel rate is allocated to satisfy various channel rate constraints such that the buffer occupancy at the decoder is maintained at a target level. If the allocated channel rate approaches the level at which the negotiated traffic descriptions may be violated, the encoder rate is decreased through adjusting quantization parameters in the MPEG encoder. In the experimental results, the video quality and the overflow and underflow probabilities at the buffer are compared at different control periods. Experiments show that the video quality and the utilization of network bandwidth resources can be optimized through the suitable selection of the control period.

• 산업공학
• /
• 제2권1호
• /
• pp.79-96
• /
• 1989

Abundant hard-working and well-educated human resources were the important sources of the spectacular economic success during the last decades. In contrast to the past sources of economic growth during the 1970's when labor and capital along with economies of scale were the dominant factors (the university has played an important role in the national economic success by supplying quality labour and intellectual talent.), the level of science, technological innovation and capital inputs will be of vital importance for future economic growth in Korea. The balance of payments in technology transfer together with the current state of R & D activities has been reviewed and some of the issues and problems underlying the university system that tend to hinder research in collaboration with research institutes and industries have been outlined. Serious imbalance in the allocation of research funds among research sectors was identified as the most serious problem to be fixed. The importance of science and technology education in private universities for the enhancement of the national level of science and technology has been re-examined. Also research and development in engineering and technical services has been emphasized. In conclusion, ways to bolster the role of universities in the research environment in cooperation with industry and research institutes have been suggested.

• 산경연구논집
• /
• 제5권2호
• /
• pp.13-20
• /
• 2014

Purpose - The purpose of this study is to empirically investigate the impact of capital structure on firm performance. Research design, data, and methodology - This study examined the impact of capital structure on the performance of cement companies listed on the Karachi Stock Exchange during the period 2009-2013. The authors hypothesize that there is a negative relationship between capital structure and firm performance. To examine the association, the authors run a Pearson correlation and multiple regression analysis. Results - Results reveal a strong negative relationship between debt to asset and firm performance variables (GPM, NPM, ROA, and ROE). Further, there is a positive relationship between debt to equity and firm performance variables (GPM and NPM), anda negative relationship between debt to equity and firm performance variables (ROA and ROE). Moreover, capital structure variables significantly impact firm performance. Conclusions - This study concluded that financial analysts and managers should emphasize on the optimal level of capital structure and efficient utilization and allocation of resources to achieve the targeted level of productive efficiency in business.

• 한국통신학회논문지
• /
• 제28권7A호
• /
• pp.467-476
• /
• 2003

본 논문에서는 블루투스(Bluetooth) 시스템의 스캐터넷(scatternet) 동작을 지원하기 위한 효율적인 MAC (Medium Access Control) 스케줄링(scheduling) 알고리즘을 제안한다. 특히 기존에 제안된 스캐터 모드(scatter mode)의 문제점을 개선하여 각 링크별 QoS (Quality of Service) 요구조건을 고려한 방안을 제시한다. 스캐터 모드는 기본적으로 스캐터넷 상의 연결된 모든 링크에 대해 동일한 서비스 기회를 제공하기 위한 방안으로, 시분할 방식을 기반으로 한다. 하지만 각각의 블루투스 기기들은 링크마다 서로 다른 트래픽 특성을 가지며, 그 양 또한 서로 다르므로 모든 링크에 대해 동일한 서비스 기회를 제공하는 것은 효율적인 서비스 슬롯(slot)의 환용이 되지 못하며 많은 무선 자원의 낭비를 가져오게 된다. 따라서 본 논문에서는 표준에서 제시하고 있는 기존의 스캐터 모드 방식을 유지하며, 상대적으로 무선 자원의 사용 효율을 높이고 각 링크마다의 트래픽 특성 및 QoS 요구조건을 수용할 수 있는 새로운 알고리즘을 제안하며, 시뮬레이션 결과를 통해 그 성능을 검증한다.

• 상하수도학회지
• /
• 제23권5호
• /
• pp.583-598
• /
• 2009

From the engineering standpoint, this study puts a special emphasis on application of adaptive management. To do this, we analyze the recent issue about water scarcity of the Gwangdong dam. Using the system dynamics model, we defined the system including water balance in the dam, dam manager's operation rules, regional water supply and local water distribution, and customer damage. It was expected that the model is useful to explain the real case, and also water scarcity of Gwangdong led to total damage of about 2.56 billion won, mainly to customers in the Taebaeck city. Two adaptive management options (i.e., optimal allocation of limited water resources, and early control of dam storage) were applied to the model in order to examine whether adaptive management is effective to mitigate the damage, it is concluded that the case study could largely reduce or entirely avoid the damage with adaptive engineering options.

• 수산경영론집
• /
• 제26권1호
• /
• pp.41-54
• /
• 1995

Recently our government intended to change the present fisheries management system into the allocated catch quota system, which is to increase the income of fishermen and to recover the depleted resources up to a desirable level. This paper is to find out the difficulties of introducing the allocated catch quota system into our fisheries mangement system and to reduce the possible errors for the enforcement of this system. The allocated catch quota system can be devided by two kinds, the one is to allocate among industries or fisheries with total allowable catch(TAC) and the other is to allocate among fishermen or individual vessels with individual fish quota(ITQ). The latter is a much advanced control system compared with the former and is what this study treats. This paper reviewed the case of Newzealand and Canada where the ITQ system is introduced earlier and classified the problems by two parts for successful introduction into Korea as follows : (1) allocation method problems, (2) enforcement problems. For the first part the problems to be considered are 1) a scientific oath qouta calculation system is necessary, 2) the quota must be opened, 3) by-catch problems. 4) interactions with adjoining countries. For the second part the problems to be considered are 1) monitoring system, 2) quota transferability, 3) quota flexibility, 4) the enforcement of the system must be connected with the reduction of fishing power, 5) a mass communication and decision making system between government and fishermen is essential.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제11권3호
• /
• pp.1492-1509
• /
• 2017

The wireless sensor network (WSN) is a key technology to support the Internet of things (IoT) paradigm. The efficiency of the MAC protocol in WSN is very important to take scalability with restricted wireless resources. The DESYNC-TDMA has an advantage of simple distributed slot allocation inspired by nature, but there is a critical disadvantage of split slots by firing message. The basic split slot model has less efficiency for continuous packet transmitting because of wasting of the slots less than the packet size. In this paper, we propose a firing offset adjustment scheme to improve the efficiency of slot utilizations, which can manage the slot assigned to each node as a single large block, called the single slot model. The performance analysis models for both the existing and the proposed schemes are also derived. Experimental results show that the proposed method provide better efficiency of slot utilization than the existing schemes without any loss of the nature of the desynchronization.

• 한국정보통신학회논문지
• /
• 제16권2호
• /
• pp.373-377
• /
• 2012

현재 RFID 기술을 이용한 관리 시스템은 그 효율성으로 인해 보다 많은 분야로 확대되고 있다. 기존의 센서 기술이 물적 자원을 관리하기 위한 용도에서 인원관리를 위한 분야로 확대되고 여러 환경에 따라 다양한 시스템이 개발됨에 따라 활용방법 또한 다양해지고 있다. 이에 본 논문은 선택적 환경에서 시스템이 가지는 특성을 분석하여 환경에 따른 특성 분석과 효율적인 시스템 구성을 위한 표준안을 작성하기 위해 연구되었다.