• 한국가스학회지
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• 제25권6호
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• pp.1-6
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• 2021

본 연구에서는 1(단말기):N(소형 전송기) 방식의 AMI단말기를 개발하였다. 현재 정부 주관 부처를 필두로 도시가스산업의 낙후된 계량시스템 선진화를 위해 가스 AMI 실증사업에 몰두하고 있다. 가스 스마트계량기의 보급은 사생활 침해 및 검침정보의 불확실성을 해소하고, 가스누출 감지를 통한 소비자 안전까지 대비할 수 있는 이점이 있다. 기존 스마트계량기의 경우 단말기와 전송기가 1:1 방식이었던 반면 본 기술은 1:N 방식을 적용하여 하나의 단말기로 다세대까지 확장 설치할 수 있으며, 저전력 설계를 구현하여 배터리 수명을 연장할 수 있는 기술이 적용되었다. 본 연구가 향후 가스 AMI 보급 사업에 기여할 것을 기대해본다.

• Journal of Korea Trade
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• 제25권4호
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• pp.146-163
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• 2021

Purpose - This paper examines China's impact on Korea's ICT exports considering the direct competition channel, the production shift channel, and the indirect demand channel at once. This paper also takes China's economic rebalancing into account and discusses whether it makes any differences in the effect of the three channels. Design/methodology - To quantify the effect of the three channels, I constructed a linear panel regression model and estimated it with various estimation methods including the system GMM. China's exports toward the same destination as Korea's exports, Korea's exports toward China, and the third countries' exports toward China respectively reflect the three channels. China's GVC indicators are included as well to evaluate the effect of further China's economic rebalancing. Since the present paper has a greater interest in the effect of China rather than the determinant of bilateral trade, a (fixed effect) panel model becomes more appropriate than the gravity model because timeinvariant variables in the gravity model, such as the distance and the language, are eliminated during the estimation process. Findings - The estimation results indicate that Chinese ICT exports are complementary to Korea's ICT exports in general. However, when markets are considered in subgroups, China's ICT exports could have a negative effect in the long run, especially for SITC75 and SITC76 markets, implying a possible competitive threat of China. The production shift effect turns significant during China's economic rebalancing in the markets for the advanced economies and the SITC76 product. China's indirect demand channel is also in effect significantly for the advanced economy and SITC75 commodities during China's economic rebalancing periods. In addition, this paper shows that China's transition toward upstream in the global value chain could have a positive impact on Korea's ICT exports, especially at the Asian market. Originality/value - The contribution of this paper is threefold. First, it focuses on the ICT industry for which Korea increasingly depends on China and China becomes a global hub of the GVC. Second, this paper quantitatively studies three channels in a model in contrast to the literature which mostly examines those channels separately and pays less attention to the GVC aspect. Third, by utilizing relatively recent data from the period of 2001-2017, this paper discusses whether China's economic rebalancing affects the three channels.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권4호
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• pp.1224-1248
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• 2022

In various sensor network applications, such as climate observation organizations, sensor nodes need to collect information from time to time and pass it on to the recipient of information through multiple bounces. According to field tests, this information corresponds to most of the energy use of the sensor hub. Decreasing the measurement of information transmission in sensor networks becomes an important issue.Compression sensing (CS) can reduce the amount of information delivered to the network and reduce traffic load. However, the total number of classification of information delivered using pure CS is still enormous. The hybrid technique for utilizing CS was proposed to diminish the quantity of transmissions in sensor networks.Further the energy productivity is a test task for the sensor nodes. However, in previous studies, a clustering approach using hybrid CS for a sensor network and an explanatory model was used to investigate the relationship between beam size and number of transmissions of hybrid CS technology. It uses efficient data integration techniques for large networks, but leads to clone attacks or attacks. Here, a new algorithm called SBEA (Snowball Endurance Algorithm) was proposed and tested with a bow. Thus, you can extend the battery life of your WSN by running effective copy detection. Often, multiple nodes, called observers, are selected to verify the reliability of the nodes within the network. Personal data from the source centre (e.g. personality and geographical data) is provided to the observer at the optional witness stage. The trust and reputation system is used to find the reliability of data aggregation across the cluster head and cluster nodes. It is also possible to obtain a mechanism to perform sleep and standby procedures to improve the life of the sensor node. The sniffers have been implemented to monitor the energy of the sensor nodes periodically in the sink. The proposed algorithm SBEA (Snowball Endurance Algorithm) is a combination of ERCD protocol and a combined mobility and routing algorithm that can identify the cluster head and adjacent cluster head nodes.This algorithm is used to yield the network life time and the performance of the sensor nodes can be increased.

• 한국항만경제학회지
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• 제38권2호
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• pp.123-138
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• 2022

우리나라는 동북아지역에서 아시아 허브항만의 위상을 유지하기 위해 항만시스템의 업그레이드에 막대한 예산을 투입하고 있다. 그 결과로 우리나라 대표항만인 부산항은 세계 5위 수준의 컨테이너 물동량 처리 수준을 보이고 있다. 그러나 부산항을 제외한 다른 항만은 낮은 순위에 자리하고 있다. 이 연구는 자료포락분석(DEA) 모델과 Malmquist 생산성지수(MPI)를 이용하여 국내 주요 항만의 효율성과 생산성을 분석하는데 목적이 있다. 특히 변수의 수가 의사결정단위(DMU) 수를 초과할 경우 판별력이 약해지는 DEA모델을 보완하기 주성분분석(PCA, Principal Component Analysis)을 DEA모델에 결합한 PCA-DEA모델을 이용하였다. 그리고 MPI는 다년간의 항만의 생산성을 측정하기 위하여 적용하였다. 그 결과로 우리나라 주요항만의 효율성과 생산성 순위를 결정할 수 있었으며, 광양항과 울산항 2010년과 2018년 비교시 효율성 측면에서 상위권을 보였으며, 생산성 분석 결과에 있어서 대산항과 목포항이 다른 항만에 비해 상대적으로 높게 나타났다. 이 연구결과는 항만별 경쟁력을 객관적으로 평가하고 전략을 마련하는데 활용될 수 있다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1346-1351
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• 2009

In this paper we propose a framework for an Object Relational IFC Server (OR-IFC Server). Enormous amounts of information are generated in each project. Today, many BIM systems are developed by various CAD software vendors. Industry Foundation Classes (IFC) developed by International Alliance for Interoperability (IAI) is an open standard data model for exchanging data between the various BIM tools. The IFC provides a foundation for exchanging and sharing of information directly between software applications and define a shared building project model. The IFC model server is a database management system that can keep track of transactions, modifications, and deletions. It plays a role as an information hub for storing and sharing information between various parties involved in construction projects. Users can communicate with each other via the internet and utilize functions implemented in the model server such as partial data import/export, file merge, version control, etc. IFC model servers using relational database systems have been developed. However, they suffered from slow performance and long transaction time due to a complex mapping process between the IFC structure and a relational-database structure because the IFC model schema is defined in the EXPRESS language which is object-favored language. In order to simplify the mapping process, we developed a set of rules to map the IFC model to an object-relational database (ORDB). Once the database has been configured, only those pieces of information that are required for a specific information-exchange scenario are extracted using the pre-defined information delivery manual (IDM). Therefore, file sizes will be reduced when exchanging data, meaning that files can now be effectively exchanged and shared. In this study, the framework of the IFC server using ORDB and IDM and the method to develop it will be examined.

• 분석과 대안
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• 제1권1호
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• pp.44-64
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• 2017

Russia's push in the Asia-Pacific region stems from its interests that have the national, regional and global dimensions. In their turn, the aims of this policy are civilizational, geopolitical, economic and prospective, with a long-term outlook. In the course of their achievement, cooperation with Northeast Asia's countries will play one of the key roles owing to the factors of geographic proximity, Northeast Asia's economic potential, risk hedging and a growing influence Northeast Asia exerts upon the global development. A new cooperation paradigm between Russia and the states of Northeast Asia should be based upon establishing and cementing self-reproducing ties. This is the central aim of Russian initiatives in relations, with Japan, the Republic of Korea, Democratic People's Republic of Korea, Mongolia and China. However, numerous obstacles ranging from Russia's absence in the regional free trade agreements and supply-production chains of value-added production to the permanent international instability generated by Pyongyang's missile-nuclear developments hamper the practical implementation of this task. Realizing the necessity to give an additional impetus to this new cooperative paradigm, Russia has to develop directions with an apparent consolidating effect. The most promising may be the establishment of a permanent security forum based upon Northeast Asia Peace and Security Mechanism chaired by the Russian Federation. The urgency of this measure and its expected support stem from the necessity to strengthen security in Northeast Asia, a task neither the US-led hub-and-spoke system nor ASE-AN-led multilateral dialogue venues have been able to resolve. The issues addressed at the security forum must include the unification of approaches to North Korean nuclear issue and producing a document specifying actions of the claimants on the disputed maritime territories in the "direct contact" situations. At the expert level, Russia has elaborated on the idea to establish such a forum outlining the spectrum of the key directions of cooperation. With the urgency in the establishment of this dialogue venue, its agenda has to be coordinated with the agendas of the existing security systems presented by the US alliances and the ASE-AN-led multilateral negotiations. The practical implementation of this initiative will strengthen security in Northeast Asia as its challenges will be resolved in the pre-emptive way based on coordinated approaches. Therefore, Russia as the Eurasian state will be one of the role players in the advent of the Asian century.

• ALGAE
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• 제39권1호
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• pp.17-30
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• 2024

Red macroalga Pyropia yezoensis is a high valuable cultivated marine crop. Its acclimation to cold stress is especially important for long cultivation period across winter in coasts of warm temperate zone in East Asia. In this study, the response of P. yezoensis thalli to low temperature was analyzed on physiology and transcriptome level, to explore its acclimation mechanism to cold stress. The results showed that the practical photosynthesis activity (indicated by Φ_PSII and qP) was depressed and pigment allophycocyanin content was decreased during the cold stress of 48 h. However, the F_v/F_m and non-photochemical quenching increased significantly after 24 h, and the average growth rate of thalli also rebounded from 24 to 48 h, indicating a certain extent of acclimation to cold stress. On transcriptionally, the low temperature promoted the expression of differentially expressed genes (DEGs) related to carbohydrate metabolism and energy metabolism, while genes related to photosynthetic system were depressed. The increased expression of DEGs involved in ribosomal biogenesis and lipid metabolism which could accelerate protein synthesis and enhance the degree of fatty acid unsaturation, might help P. yezoensis thallus cells to cope with cold stress. Further co-expression network analysis revealed differential expression trends along with stress time, and corresponding hub genes play important roles in the systemic acquired acclimation to cold stress. This study provides basic mechanisms of P. yezoensis acclimation to cold temperature and may aid in exploration of functional genes for genetic breeding of economic macroalgae.

• Asia pacific journal of information systems
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• 제17권4호
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• pp.31-59
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• 2007

We frequently use search engines to find relevant information in the Web but still end up with too much information. In order to solve this problem of information overload, ranking algorithms have been applied to various domains. As more information will be available in the future, effectively and efficiently ranking search results will become more critical. In this paper, we propose a ranking algorithm for the Semantic Web resources, specifically RDF resources. Traditionally, the importance of a particular Web page is estimated based on the number of key words found in the page, which is subject to manipulation. In contrast, link analysis methods such as Google's PageRank capitalize on the information which is inherent in the link structure of the Web graph. PageRank considers a certain page highly important if it is referred to by many other pages. The degree of the importance also increases if the importance of the referring pages is high. Kleinberg's algorithm is another link-structure based ranking algorithm for Web pages. Unlike PageRank, Kleinberg's algorithm utilizes two kinds of scores: the authority score and the hub score. If a page has a high authority score, it is an authority on a given topic and many pages refer to it. A page with a high hub score links to many authoritative pages. As mentioned above, the link-structure based ranking method has been playing an essential role in World Wide Web(WWW), and nowadays, many people recognize the effectiveness and efficiency of it. On the other hand, as Resource Description Framework(RDF) data model forms the foundation of the Semantic Web, any information in the Semantic Web can be expressed with RDF graph, making the ranking algorithm for RDF knowledge bases greatly important. The RDF graph consists of nodes and directional links similar to the Web graph. As a result, the link-structure based ranking method seems to be highly applicable to ranking the Semantic Web resources. However, the information space of the Semantic Web is more complex than that of WWW. For instance, WWW can be considered as one huge class, i.e., a collection of Web pages, which has only a recursive property, i.e., a 'refers to' property corresponding to the hyperlinks. However, the Semantic Web encompasses various kinds of classes and properties, and consequently, ranking methods used in WWW should be modified to reflect the complexity of the information space in the Semantic Web. Previous research addressed the ranking problem of query results retrieved from RDF knowledge bases. Mukherjea and Bamba modified Kleinberg's algorithm in order to apply their algorithm to rank the Semantic Web resources. They defined the objectivity score and the subjectivity score of a resource, which correspond to the authority score and the hub score of Kleinberg's, respectively. They concentrated on the diversity of properties and introduced property weights to control the influence of a resource on another resource depending on the characteristic of the property linking the two resources. A node with a high objectivity score becomes the object of many RDF triples, and a node with a high subjectivity score becomes the subject of many RDF triples. They developed several kinds of Semantic Web systems in order to validate their technique and showed some experimental results verifying the applicability of their method to the Semantic Web. Despite their efforts, however, there remained some limitations which they reported in their paper. First, their algorithm is useful only when a Semantic Web system represents most of the knowledge pertaining to a certain domain. In other words, the ratio of links to nodes should be high, or overall resources should be described in detail, to a certain degree for their algorithm to properly work. Second, a Tightly-Knit Community(TKC) effect, the phenomenon that pages which are less important but yet densely connected have higher scores than the ones that are more important but sparsely connected, remains as problematic. Third, a resource may have a high score, not because it is actually important, but simply because it is very common and as a consequence it has many links pointing to it. In this paper, we examine such ranking problems from a novel perspective and propose a new algorithm which can solve the problems under the previous studies. Our proposed method is based on a class-oriented approach. In contrast to the predicate-oriented approach entertained by the previous research, a user, under our approach, determines the weights of a property by comparing its relative significance to the other properties when evaluating the importance of resources in a specific class. This approach stems from the idea that most queries are supposed to find resources belonging to the same class in the Semantic Web, which consists of many heterogeneous classes in RDF Schema. This approach closely reflects the way that people, in the real world, evaluate something, and will turn out to be superior to the predicate-oriented approach for the Semantic Web. Our proposed algorithm can resolve the TKC(Tightly Knit Community) effect, and further can shed lights on other limitations posed by the previous research. In addition, we propose two ways to incorporate data-type properties which have not been employed even in the case when they have some significance on the resource importance. We designed an experiment to show the effectiveness of our proposed algorithm and the validity of ranking results, which was not tried ever in previous research. We also conducted a comprehensive mathematical analysis, which was overlooked in previous research. The mathematical analysis enabled us to simplify the calculation procedure. Finally, we summarize our experimental results and discuss further research issues.

• 통상정보연구
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• 제14권3호
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• pp.585-610
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• 2012

지금까지 전자결제 상용화 서비스를 제공하기 위한 다양한 시도는 있었으나, 실제로 상용화 서비스로 이용되고 있는 전자결제 모델은 거의 없고, 그 중에서 SWIFT의 TSU(Trade Service Utility) 만이 실현가능성이 가장 높은 것으로 평가받고 있다. 한국의 경우에는 전자무역촉진3개년사업을 통하여 e-L/C 유통관리시스템이 구축되었는데, 이는 세계 최초의 전자신용장서비스에 해당된다. SWIFT신용장을 전자신용장이라고 보는 견해가 몇몇 학자들에 의해 주장되고 있는데, 이는 신용장의 발행에서 통지에 이르기까지의 일련의 과정이 SWIFT 방식을 통해서 이루어지고 있는 현상에서 SWIFT를 통해 통지되는 신용장을 SWIFT신용장이라고 부르는 것에 지나지 않는다는 점에서 그릇된 견해라고 할 수 있다. 왜냐하면 완전한 전자신용장 시스템은 SWIFT망과 접속되어 유기적으로 연동될 수 있도록 되어야 할 뿐만 아니라 해외의 은행과 은행의 고객 간의 전자신용장 업무도 유기적으로 연결되어야만 가능한 것이기 때문이다. 본 논문의 연구 목적은 국내외 전자결제 관련 인프라 현황을 살펴보고, 향후 국제적으로 도입될 전자결제 인프라를 모색해봄으로써 우리나라 전자신용장 유통시스템의 구축과 상용화에 조금이나마 일조하고자 함이다.

• 한국항만경제학회지
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• 제35권3호
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• pp.19-40
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• 2019

세계 경제 침체와 수출입 부진으로 인해 항만이 어려움을 겪고 있는 반면 세계 식품콜드체인 시장은 빠르게 성장하고 있다. 수입 측면에 인천항은 최대 소비지역 수도권을 배후권역으로 수도권 관문항의 역할을 담당하는 지리적 이점을 지니고 발전해오고 있다. 수출 측면에 중국 국민들은 지속적으로 증가하게 되어 콜드 체인 식품 소비수요가 꾸준히 증가하고 있다. 인천항은 북중국의 주요 항만들과의 거리는 매우 짧아서 인천항이 대중국 가공식품 물류중심기지로 대중국 신선물류 유통의 거점으로 육성될 가능성이 크다. 콜드체인 물류체계 구축은 인천항 물류의 고부가가치 창출의 유력한 수단이라고 할 수 있다. 본 연구는 선행연구와 인터뷰 등을 토대로 먼저 SWOT분석을 통해 인천항의 강점, 약점, 기회와 위협요인에 의해 인천항의 경쟁발전 전략을 탐색, 제시하였다. 그 다음에 AHP 분석 요인으로 인프라요인, 운영요인, 비용요인, 기술요인 순으로 나타났으며, 인프라요인 중 냉동기술의 가중치가 제일 높게 나타났다. 본 연구에서 처음으로 인천항 콜드체인 활성화 요인에 있어서 인프라요인이 매우 중요하다는 것을 밝혀냈다. 분석결과에 의해 인천항 콜드체인에 대한 정책과 전략적 방향을 제시하였다.