• 산업공학
• /
• 제9권3호
• /
• pp.72-80
• /
• 1996

As the fiber optic technology is rapidly being deployed in telecommunication networks, particular emphasis is placed on the survivability in designing networks. Most of the survivable network design models proposed to date have connectivity constraints, which cannot precisely define a network topology owing to the multiplicity of feasible ones. In this paper, we propose a k-link survivable network design model incorporating traffic-based survivability constraints which restrict the lost traffic due to a network failure under a prescribed level. Our model is shown to include the existing connectivity models as special cases. Then we present its integer programming formulation, analyze the structural properties, and develop a heuristic for obtaining low cost survivable networks.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제5권3호
• /
• pp.189-195
• /
• 2005

One of the major components of any pervasive system is its proactive behavior. Various models have been developed to provide system wide changes which would enable proactive behavior. A major drawback of these approaches is that they do not address the need to make use of existing applications without modifying the applications. To overcome this drawback, a middleware architecture called 'Concord' is proposed. Concord is based on a simple model which consists of Lookup Server and Database. The rewards for this simple model are many. First, Concord uses the existing computing infrastructure. Second, Concord standardizes the interfaces for all services and platforms. Third, new services can be added dynamically without any need for reconfiguration. Finally, Concord consists of Database that can maintain and publish the active set of available resources. Thus Concord provides a solid system for integration of various entities to provide seamless connectivity and enable proactive behavior.

• 지능정보연구
• /
• 제14권2호
• /
• pp.1-20
• /
• 2008

정보기술의 급격한 발전은 경영환경에서 다양한 정보를 산출하여 의사결정자들이 의사결정을 효과적으로 지원할 수 있는 수단을 요구하고 있다. 특히 유비쿼터스 환경의 등장으로 이러한 의사결정형태는 더욱 복잡해지고 다양해 질것으로 기대된다. 이에 본 연구에서는 유비쿼터스 환경에서의 의사결정지원시스템(UDSS：Ubiquitous Decision Support Systems)이 실제 업무에서 의사결정과정과 의사결정의 성과에 어떠한 영향을 미치는지 실증적으로 분석하고자 하였다. 이를 위해 모바일 택배 시스템(MDS：Mobile Delivery System)을 UDSS로 간주하고 유비쿼터스 환경의 주요한 두 속성인 유비쿼터스 접속성과 상황인식기능이 의사결정자의 의사결정과정과 성과에 어떠한 영향을 미치는지 실증자료를 이용하여 분석하였다. 분석결과 유비쿼터스 접속성은 의사결정과정에서 대안설계에 유의한 영향을 미치지 못하였으나, 상황인식기능은 의사결정의 모든 과정에 유의한 영향을 미치는 것으로 나타났다. 한편, 의사결정과정 간의 각 단계들은 상호 유의한 인과관계를 나타냈으며, 의사결정과정과 의사결정의 성과는 모두 유의한 것으로 나타났다. 이러한 결과를 바탕으로 향후 UDSS의 설계 및 구현에 필요한 시사점 및 향후 연구방향을 제시하였다.

• 한국환경복원기술학회지
• /
• 제22권6호
• /
• pp.97-114
• /
• 2019

This study aims to analyze the effect of urban ecosystem restoration projects by evaluating the short-term restoration performance of the project sites, from both qualitative and quantitative evaluations. In this study, for the qualitative evaluation, we derived the evaluation frame from previous studies and literature. For the quantitative evaluation, the changes in ecological connectivity after the restoration project were described using landscape permeability and network analysis. In addition, changes in habitat quality after the restoration project were evaluated by using InVEST Habitat Quality Model. These evaluations were applied to the three natural madang (ecological restoration) projects and two ecosystem conservation cooperation projects. As a result, three categories, 10 indicators, and 13 sub-indicators were derived from literature as the evaluation frame for this study. In the case of quantitative evaluation of restoration performance, habitat quality increased by 45% and ecological connectivity by 37% in natural-madang, and habitat quality by about 12% and ecological connectivity by about 19% in ecosystem conservation cooperation projects. This implies that the ecological restoration project can increase the ecological connectivity and the habitat quality of degraded sites even in a short period of time by improving the land-cover and land use. The results by applying the evaluation frame indicated that ecological and environmental factors and the ecological functions were improved by the restoration works, even though the magnitude of performances were diverse depending on the specific evaluation items, project type, and site characteristics. This study clarified that the success of ecological restoration project should be assessed by both of the short-term and long-term goals, which can be achieved by the maintenance and sustainable management, respectively.

• 대한기계학회논문집A
• /
• 제20권3호
• /
• pp.910-932
• /
• 1996

A problem of determining the effective conductivity of a useful model of sphere-matrix type, disordered three-phase composite media is considered. Specifically, a three-phase media in which two-phase composite spheres, consisting of spheres of conductivity $k_2$((phase 2) and concentric shells of conductivity $k_3$(phase 3), are randomly distributed in a matrix of conductivity $k_1$( (phase 1) is considered. As for the structure models configuring three-phase composite media, three different structure models of PCS, PS-1 and PS-2 models are defined, which are analogous to well-established PCS, PS structure models of two-phase composite media. Futhermore, a generalized PS-PCS structure model is proposed to incorporate thesee three different models in one. Effective condectivity $k^{\ast}$of multiphaes composite media is greatly influenced by the phase connectivity of each disspersed phase material, as well as phase conductivities and phase volume fractions. Phase connectivity of three-phase PCS, PS-1, PS-2 composite media is quantified by the impentrability parameter $\lambda$. Mathematically rigorous first-order cluster bounds on $k^{\ast}$ are derived for these models of three-phase composite media, and as computation examples, first-order cluster bounds on $k^{\ast}$ for three-phase composites consisting of largely different phase conductivities are computed and compared as function of concnectivity parpmeter $\lambda$. Results and discussions are given.

• 한국습지학회지
• /
• 제16권2호
• /
• pp.213-220
• /
• 2014

최근 하천정비는 환경에 대한 인식이 높아지면서 이수 및 치수뿐만 아니라 하천환경에 대한 관심이 증가하는 쪽으로 바뀌어가고 있는 실정이다. 따라서, 하천환경 또는 하천복원이 하천사업의 핵심이 되고 있다. 우리나라의 경우, 대부분의 하천이 치수목적의 하천정비에 의해 홍수조절과 주운을 돕기 위해 직강화 되었다. 하도를 직강화 할 경우 안정성 유지가 중요하므로 하천을 따라 제방이 축조된다. 이와같이 이수와 치수를 목적으로 하천에 축조된 댐, 보, 제방 및 수문 등과 같은 구조물의 경우, 하천의 종 횡적 연결성(Connectivity)을 저해하는 요인이 된다. 연결성이란 어떤 서식처에서 다른 서식처로 에너지와 물질을 이동시키거나 자연적인 수로를 통하여 서식처 간을 물리적으로 연결하는 동적인 자연통로로써 장기적인 하천복원관점에서 볼 때 연결성 증대는 유역 내 건강한 생태계 조성을 위해 매우 중요하다. 본 연구에서는 횡적 연결성 회복을 통한 하천복원의 첫 번째 단계로써 연결성에 대한 기본개념을 설명하고 대상유역을 선정하여 연결성을 저해하는 격리, 차단 공간의 유무에 따른 유역 내 흐름양상의 변화를 수치모의 하였다. 본 연구의 결과는 유역 내 수리수문연결기술 개발로 이어질 수 있을 것으로 판단되며, 차후 하천복원사업에 기여할 수 있을 것으로 판단된다.

• 대한기계학회논문집A
• /
• 제21권9호
• /
• pp.1414-1421
• /
• 1997

This paper examines the physics and mechanics governing the dynamic interaction between physical systems and suggests the four structures of bond graph prototypes, considered as a general model that can promise their dynamic behavior physically resonable. The bond graph prototypes originating from the paper are more realistic junction structures than those used to model dynamic systems conventionally by bond graph standards in whether physical constraints are involved or not when the energy exchange between two dynamic components arises. It is shown that the bond graph prototypes are dynamic or energetic in their describing equations compared to the bond graph standards, and connectivity and causality are properties of dynamic systems upon which the steps developed in this paper for the bond graph prototypes are wholly based and their definitions an concepts are highly emphasized all through the paper.

• Genomics & Informatics
• /
• 제3권1호
• /
• pp.30-34
• /
• 2005

Microarray technology makes it possible to measure the expressions of tens of thousands of genes simultaneously under various experimental conditions. Identifying differentially expressed genes in each single experimental condition is one of the most common first steps in microarray gene expression data analysis. Reasonable choices of thresholds for determining differentially expressed genes are used for the next-stap-analysis with suitable statistical significances. We present a supervised model for identifying DEGs using pathway information based on the global connectivity structure. Pathway information can be regarded as a collection of biological knowledge, thus we are trying to determine the optimal threshold so that the consequential connectivity structure can be the most compatible with the existing pathway information. The significant feature of our model is that it uses established knowledge as a reference to determine the direction of analyzing microarray dataset. In the most of previous work, only intrinsic information in the miroarray is used for the identifying DEGs. We hope that our proposed method could contribute to construct biologically meaningful structure from microarray datasets.

• 한국의류학회지
• /
• 제42권1호
• /
• pp.183-194
• /
• 2018

This study investigated the characteristics of Omni Channel and examined the influence of them on consumers' perceived functional value and emotional value as well as the effect of perceived functional value and emotional value on user's intention of use through Omni Channel. To verify the research model, the questionnaire survey was conducted on 20's to 40's men and women residing in Seoul and the metropolitan area by convenience sampling. The number of copies used for data analysis was 696. To verify the research model, factor analysis, reliability analysis, and structural equation model analysis were performed using AMOS 20.0. First, Omni Channel characteristics consisted of four factors: instant connectivity, location-based provability, interactivity, and entertainment. Second, the instant connectivity, location-based provability and entertainment positively influenced functional value and emotional value; however, the interactivity was significant only to the emotional value. Third, consumers' perceived value of Omni Channel characteristics had a significant effect on attitude. Fourth, the more favorable the attitude toward Omni Channel is higher for the intention to use Omni Channel.

• Asia pacific journal of information systems
• /
• 제26권4호
• /
• pp.489-508
• /
• 2016

Growth in the use of mobile commerce services (MCS) as an enabler to conduct business more effectively has been phenomenal. Technology acceptance model (TAM) has been applied in different contexts to examine a wide range of information technology. As more and more companies are finding ways to utilize MCS, an important issue is to understand what factors will affect the decisions of consumers in adopting the services. Based on TAM with two additional groups of external factors (i.e., service-related factors [ubiquitous access and contextual service] and technology-related factors [perceived security risk and network connectivity]) that are theoretically justified to affect both perceived usefulness and perceived ease of use, which are also considered, a research model for the investigated technology acceptance was developed and empirically examined. The major results of this study are as follows. First, ubiquitous access affects perceived usefulness and perceived ease of use. Contextual service affects perceived usefulness. Second, perceived security risk affects perceived usefulness and perceived ease of use. Finally, network connectivity affects perceived usefulness and perceived ease of use.