• 자원ㆍ환경경제연구
• /
• 제11권3호
• /
• pp.493-513
• /
• 2002

This empirical study analyzed the policy effect of deregulation in oil product prices. To investigate the effect of deregulation, it is tested whether gasoline prices are determined by market power. Also, the role of government in gasoline tax system is investigated. The empirical analysis has been done by using error correction model. The major findings are as follows. First of all, no significant empirical evidence is found to support that the deregulation affects the determination of gasoline prices. Secondly, the short-term CIF elasticity is estimated to be 0.14. This finding implies that if CIF increases 10%, the gasoline prices increase 1.4%. Finally, the investigation on government role in deregulated market shows that the government has still exercise the power of control through the tax system. For example, the government is seemed to increase the gasoline price more than the increase amount caused by the international oil prices and the exchange rates, because of the intention to achieve the internal revenue increases and lead to gasoline conservation.

• 자원ㆍ환경경제연구
• /
• 제11권3호
• /
• pp.447-463
• /
• 2002

The heat demand prediction is an essential issue in management of district heating system. Without an accurate prediction through the lead-time period, it might be impossible to make a rational decision on many issues such as heat production scheduling and heat exchange among the plants which are very critical for the district heating company. The heat demand varies with the temperature as well as the time nonlinearly. And the parametric specification of the heat demand model would cause a misspecification bias in prediction. A nonparametric model for the short-term heat demand prediction has been developed as an alternative to avoiding the misspecification error and tested with the actual data. The prediction errors are reasonably small enough to use the model to predict a few hour ahead heat demand.

• 한국지능시스템학회논문지
• /
• 제17권1호
• /
• pp.123-129
• /
• 2007

On the Semantic Web, the content of the documents must be explicitly represented through metadata in order to enable contents-based inference. In this study, we propose a mechanism to convert the Conceptual Graph (CG) into Resource Description Framework (RDF). Quite a large number or representation languages for representing knowledge on the Web have been established over the last decade. Most of these researches are focused on design of independent knowledge description. On the Semantic Web, however, a knowledge conversion mechanism will be needed to exchange the knowledge used in independent devices. In this study, the CG could give an entire conceptual view of knowledge and RDF can represent that knowledge on the Semantic Web. Then the CG-based object oriented PROLOG could support the natural inference based on that knowledge. Therefore, our proposed knowledge conversion mechanism will be used in the designing of Semantic Web-based knowledge representation and inference systems.

• 산업공학
• /
• 제11권1호
• /
• pp.155-163
• /
• 1998

In multiparty multimedia communication, each participant not only receives information from other participants but also generates real-time data streams to distribute to others and therefore the difference between source and destination is not clear in terms of data transmission. During a teleconference session, many sub-multicast trees may be generated to exchange information to specific members within the multicast group and if those sub-multicast trees use the same fixed multicast tree, the blocking probability will be high and it is hard to provide QoS for each sub-multicast group. Also, even though there exits some shortcuts between each sub-multicast group, fixed multicast tree does not allow to use those shortcuts. Thus to overcome these problems. We propose a network resource reservation protocol and show that its effectiveness in terms of blocking probability and network resources usage.

• 가족자원경영과 정책
• /
• 제19권1호
• /
• pp.111-138
• /
• 2015

The purpose of this study was to understand the lived experiences of grandmothers and family in transition. Grandmothers in transition means grandmothers who had married children at least one even if there are no grandchildren yet. The data for this study came from 20 grandmothers in transition of 5 focus group(each 4 persons) interview. 9 of them was pre-grandmother without grandchildren yet, 11 was grandmother who had grandchildren. The result of this study revealed that the meaning of grandmotherhood. Dynamics of family in transition around supporting child care represent change of family relations. It didn't means 'empty-nest' model of foreign theory. The Absolute quantity of intergeneral exchange and conflict extended as three generational families.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권2호
• /
• pp.565-581
• /
• 2019

This paper investigates the wireless powered two way relay network (WPTWRN), where two single-antenna users and one single-antenna relay firstly harvest energy from signals emitted by a multi-antenna power beacon (PB) and then two users exchange information with the help of the relay by using their harvested energies. In order to improve the energy transfer efficiency, energy beamforming at the PB is deployed. For such a network, to explore the performance limit of the presented WPTWRN, an optimization problem is formulated to obtain the achievable rate region bounds by jointly optimizing the time allocation and energy beamforming design. As the optimization problem is non-convex, it is first transformed to be a convex problem by using variable substitutions and semidefinite relaxation (SDR) and then solve it efficiently. It is proved that the proposed method achieves the global optimum. Simulation results show that the achievable rate region of the presented WPTWRN architecture outperforms that of wireless powered one way relay network architecture. Results also show that the relay location has significant impact on achievable rate region of the WPTWRN.

• The Journal of Asian Finance, Economics and Business
• /
• 제8권1호
• /
• pp.257-269
• /
• 2021

Intellectual capital is becoming a crucial factor for a firm's long-term profit and performance in the knowledge-based economy as more firms identify their core competence as invisible assets rather than visible assets (Itami, 1987). The company was encouraged to measure financial and non-financial factors, including the customer perspective groups, the internal business process, learning and growth perspective, then to link all these measurements in a coherent system. This paper seeks to investigate the influence of intellectual capital elements on company performance, as well as the relationship among intellectual capital elements from a cause-effect perspective. Resource-Based View (RBV) considers intellectual capital as resource and capability to sustain competitive advantage on company performance. The partial least squares approach is used to examine listed banks in Indonesia Stock Exchange for year 2017-2019. Results show that human capital directly has positive influences on innovation capital, customer capital, and process capital. Innovation capital has positive, but less significant influence on process capital, which in turn influences customer capital. Human capital and process capital also influence customer capital. Finally, customer capital contributes to performance. This study helps management to identify relevant intellectual capital elements as competitive advantage and their indicators to enhance business performance.

• 한국환경과학회지
• /
• 제33권4호
• /
• pp.235-247
• /
• 2024

A total of 64 individuals of Acanthogobius flavimanus, which inhabit the coast of Korea, were collected from 8 regions from July to August 2023. A haplotype network and a phylogenetic tree were created. The genomic DNA of the target fish species was compared and analyzed with the genomic DNA of four regions in Japan downloaded from the National Center for Biotechnology Information (NCBI). In the haplotype network of Acanthogoboius flavimanus, Eocheong-do (EC) and Goseong (MAJ) exhibited low genetic similarity with other regions in Korea and Japan. The Phylogenetic tree showed that the population of MAJ exhibited differences in genetic structure compared to populations in other regions of Korea and Japan, indicating a distant relationship. Most marine organisms are known to migrate and spread via ocean currents, which is the most crucial factor promoting gene flow through larvae between populations. The haplotype of Acanthogobius flavimanus in MAJ differs from the haplotypes in Korea and Japan. The population in MAJ is believed to have limited genetic exchange due to the North Korea Cold Currents. We identified haplotype patterns based on the geographical distribution of Acanthogobius flavimanus off the coast of Korea and inferred that ocean currents have some influence on genetic distances.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
• /
• pp.217-220
• /
• 2006

This paper briefly presents the AIS land infrastructure in Sweden and how it is used as a common resource by multiple users. Some of the applications for the AIS information within the Maritime Administration are presented. It also discuss international co-operation concerning AIS land infrastructure, exchange of AIS information and possible future development. Existing and expected problems with AIS are shown and mitigation measures presented.

• 공업화학
• /
• 제20권1호
• /
• pp.80-86
• /
• 2009

파라자일렌 분리용 흡착제로서 효과적인 결합제가 없는 제올라이트 BaX 성형체를 제조하는 방법에 대하여 검토하였다. 제올라이트 NaX 타입의 결정분말을 무기결합제인 colloidal silica sol (C.S.) 용액과 기공형성제인 microcrystalline cellulose 분말을 이용하여 구형화 한 후 소성, binderless 처리, 바륨 이온교환, 활성화 등의 단계를 거치면서 넓은 비표 면적과 우수한 강도 및 파라자일렌에 대한 선택도를 갖는 파라자일렌 분리용 흡착제를 제조하였다. 각 시료의 무기결합제$SiO_2$함량을 14.0 wt%, 18.0 wt%, 22.3 wt%로 조절하여, 무기결합제의 함량 증가에 따른 시료 강도의 변화에 대해 검토하였다. 구형화 시료의 무기결합제 함량이 증가 될수록 binderless 처리 후의 강도가 증가함을 확인할 수 있었다. 이렇게 제조된 시료에 무게비 1 : 1 : 1로 혼합된 혼합자일렌 용액으로 $90^{\circ}C$에서 회분식 흡착실험을 수행해본 결과, 본 연구에서 제조된 binderless zeolite BaX는 파라자일렌에 선택적인 흡착능을 보임을 확인하였다. 이렇게 제조된 흡착제는 충분한 강도(0.450 kgf)와 결정화도(98.53%), BET 비표면적$(647.57m^2/g)$을 가지면서, 파라자일렌을 선택적으로 흡착함을 확인할 수 있었다.