• 대한수학회지
• /
• 제44권2호
• /
• pp.327-342
• /
• 2007

In this paper, a kind of pest-predator model with impulsive effect and infinite delay is considered by the method of chain transform. By using Floquet's theorem, it is shown that there exists a globally asymptotically stable periodic pest eradication solution when the impulsive period is less than or equal to some critical value which is a directly proportional function with respect to the population of release. Furthermore, it is proved that the system is permanent if the impulsive period is larger than some critical value. Finally, the results of the corresponding systems are compared, those results obtained in this paper are confirmed by numerical simulation.

• Bulletin of the Korean Chemical Society
• /
• 제12권4호
• /
• pp.411-413
• /
• 1991

The effects of electrolyte on the critical micelle concentration (cmc) and bromide counterion binding in the micelles of cetylpyridinium bromide (CPB) have been investigated by UV spectroscopy and conductance measurements. Salts used in this study decreased cmc in the order $Cl^-\;<\;Br^-\;<\;NO3^-$ (which parallels the lyotropic series for the inorganic anions) and the effects on cmc followed the equation proposed by Shinoda: log cmc = A - B log (cmc + [NaX]). In the equation, constant B represents the counterion binding to the micelles at cmc and for the micelle of CPB at $25^{\circ}C$, B=80.76%. The association constant for the binding of counterions to long chain cations within micelles was also derived from the cmc values and counterion binding constant to the micelles.

• 국제학술발표논문집
• /
• The 2th International Conference on Construction Engineering and Project Management
• /
• pp.759-768
• /
• 2007

Construction is one of the most hazardous industries due to its unique nature. Recent occurrences of highly publicised and criticized construction site accidents have highlighted the immediate need for the construction industry to address safety hazards. Safety used to be addressed as an isolated issue in the past, but the problem of safety is an emergent property of a system. In general, it seems that both industrial practitioners and government officials have tended to address safety by focusing on technical aspects and looking for immediate causes of accidents after they have taken place. The objective of this paper is to examine issues and critical factors that affect the safety standards from a holistic point of view. The job of making worksites safe should not just fall squarely on the contractors but should be shared by all parties in the value chain of construction activities.

• 전자통신동향분석
• /
• 제38권4호
• /
• pp.58-69
• /
• 2023

Cyberspace is emerging as a critical domain requiring national-level governance and international cooperation owing to its potential financial and societal impacts. This research aims to investigate the cybersecurity policies from major countries for understanding with comprehensive perspectives. Global trends emphasize a comprehensive command-centered approach, with top leadership directing cybersecurity policies. Key policy areas include security across technology ecosystems, protection of critical infrastructure, and software supply chain security. Investment is being focused on zero-trust architectures, software bills, and new technologies like artificial intelligence. For countries like Korea, immediate response and adaptation to these trends are crucial to develop and enforce national cybersecurity policies.

• 국제학술발표논문집
• /
• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
• /
• pp.201-208
• /
• 2011

Today's highly competitive construction scenario forces all the major players in the field to take up multiple projects which have put an undue pressure on the resources available within the organization. Under such a situation, there are many instances where in the resource requirement exceeds its availability due to multiple activities (with same resource requirement) which are scheduled to start simultaneously and thus results in the constrained resource becoming a bottleneck of the project. As a consequence of sharing resources, this paper studies the impact on the completion date of two similar projects under two different conditions, the first one resulting in a postponed end date and the second without any postponement. The resource utilization, the possibility of substitution of a resource and its subsequent impact on the deadline of the project is analyzed under these two circumstances. The study is done on a Critical Chain Project Management (CCPM) platform instead of leaving the schedule with a traditional Critical Path Method (CPM) finish, which gives an added advantage of validating the robustness of the emerging CCPM trend in the field of resource management.

• 한국통신학회논문지
• /
• 제39C권9호
• /
• pp.828-840
• /
• 2014

사물을 인터넷에 연결시키는 기술인 Internet of Things(IoT)는 새로운 연구분야가 되어 기술적으로 많은 발전이 이루어져왔다. 이러한 IoT 기술은 사물을 관찰하거나 다루는데 있어 쉽게 접근하도록 하여 네트워크 상에서 인터넷으로 데이터의 전달을 가능하게 한다. 이는 두가지의 인프라를 필요로 하는데 하나는 데이터를 수집하는 Sensing Entity이고 다른 하나는 데이터를 점유하는 Sensor Cloud이다. 여기서 무선 센서 네트워크는 사물로부터 측정되는 데이터를 인터넷에 연결시키는데 매우 중요한 역할을 하는데 간단한 컴퓨팅 디바이스나 Arduino, Raspberry Pi와 같은 임베디드시스템으로 구성될 수 있다. Sensor Cloud는 사물로부터 측정되어 나오는 데이터의 공유나 처리를 하도록 하는 클라우드 컴퓨팅으로 모니터링 혹은 컨트롤 시스템에 대한 플랫폼을 제공한다. 본 논문에서는 의약품의 저장 조건들을 모니터링 하는 Cold Chain을 제안한다. 제안된 Cold Chain은 생산에서 소비단계까지 이르는 이동이나 저장상태에 대한 여러 환경적 조건인 습도, 온도, 저장 장소 등을 모니터링 하는 시스템이다. 시스템은 두개의 부시스템으로 구성되는데 하나는 이동에 관련된 것을 다루고 다른 하나는 저장에 관련된 것을 다룬다. 이 두 개의 시스템은 보다 향상된 모니터링 방법을 제공하기 위해 Sensor Cloud 시스템으로 통합된다.

• 디지털융복합연구
• /
• 제20권2호
• /
• pp.9-20
• /
• 2022

공급망 공격은 주요기반시설을 타겟하여 피해 규모가 크고 공공 안전 및 국가안보를 위협하는 요소로 진화하고 있다. 이에 사이버안보 전략 및 정책 수립 시 공급망 위험관리를 명시하여 보안성을 제고하고 있으며, 2021년 미(美) 바이든 행정부가 발표한 국가 사이버안보 강화를 위한 행정명령에서는 소프트웨어 공급망 보안 강화를 위한 지침 중 일부로 SBOM을 언급하였다. 정부 차원에서 SBOM을 의무화하여 공급망 보안 검증 도구로 활용한다면, 향후 국내 조달체계에도 영향을 받을 수 있으며 정책 시행 경과에 따라 국내 공급망 보안 체계 수립 시에도 참고 가능할 것으로 보인다. 이에 따라 본 논문에서는 소프트웨어 공급망 보안 강화 방안으로써 SBOM 정책을 추진 중인 국가를 선정하여 관련 사례를 중점으로 분석하였다. 또한, 국외 SBOM 정책 동향의 비교·분석을 통하여 국내 SBOM 도입 시 기술, 정책, 법률측면에서의 활용 방안을 고찰하였다. 향후 공급망 무결성·투명성 검증 도구로 SBOM의 활용 가치가 기대되는바 SBOM에 대한 국제적 표준화 정립 및 정책 개발에 관한 지속적인 동향 파악과 표준 형식 개발 연구가 요구된다.

• 경영정보학연구
• /
• 제25권3호
• /
• pp.139-162
• /
• 2023

디지털 기술의 등장과 발전으로 기업은 디지털 기술을 공급-수요 사슬에 도입하여 관리하는 것이 필수적이 되었다. 그러나 이와 관련하여 여러 어려움, 그 중에서도 특히 디지털 공급-수요 사슬을 체계적으로 평가하는 어려움이 또한 늘고 있다. 그 이유는 산업계와 학계에 걸쳐 전반적으로 사용되는 표준화된 평가기준이 아직 부족하기 때문이다. 이에 따라, 본 논문에서는 사용자의 경험을 하나의 평가기준으로 제시하고자 한다. 따라서 세 개의 다른 포커스 그룹을 통해 데이터를 얻어 질적 분석 기법으로 연구하였다. 포커스 그룹 참여자들은 넷플릭스를 공급-수요 사슬의 예로 삼아 넷플릭스에 대한 사용 경험을 자유롭게 이야기 하였다. 넷플릭스는 디지털 콘텐츠, 즉 제품을 직접 소비자에게 전달하기 때문에 소비자의 일반적인 경험, 이 회사의 추천시스템에 대한 경험, 그리고 이와 관련된 정보 보안에 대한 인식이 매우 중요하다. 이러한 것들이 기존 고객의 만족도를 높이는 것은 물론, 새로운 고객의 유치에도 결정적인 역할을 할 수 있기 때문이다. 디지털 공급-수요 사슬에 대한 사용자의 일반적인 경험은 기업의 평가 척도에 중요하다. 또한 이러한 추천시스템과 이와 관련된 정보 보안은 디지털 공급-수요 사슬의 일부이다. 따라서 이에 대한 사용자의 경험과 인식을 측정하는 것은 디지털 공급-수요 사슬을 평가하는 데에 중요한 척도가 될 것이다.

• Asia pacific journal of information systems
• /
• 제17권4호
• /
• pp.207-228
• /
• 2007

Measuring Information Technology(IT) organizations' activities have been limited to mainly measure financial indicators for a long time. However, according to the multifarious functions of Information System, a number of researches have been done for the new trends on measurement methodologies that come with financial measurement as well as new measurement methods. Especially, the researches on IT Balanced Scorecard(BSC), concept from BSC measuring IT activities have been done as well in recent years. BSC provides more advantages than only integration of non-financial measures in a performance measurement system. The core of BSC rests on the cause-and-effect relationships between measures to allow prediction of value chain performance measures to allow prediction of value chain performance measures, communication, and realization of the corporate strategy and incentive controlled actions. More recently, BSC proponents have focused on the need to tie measures together into a causal chain of performance, and to test the validity of these hypothesized effects to guide the development of strategy. Kaplan and Norton[2001] argue that one of the primary benefits of the balanced scorecard is its use in gauging the success of strategy. Norreklit[2000] insist that the cause-and-effect chain is central to the balanced scorecard. The cause-and-effect chain is also central to the IT BSC. However, prior researches on relationship between information system and enterprise strategies as well as connection between various IT performance measurement indicators are not so much studied. Ittner et al.[2003] report that 77% of all surveyed companies with an implemented BSC place no or only little interest on soundly modeled cause-and-effect relationships despite of the importance of cause-and-effect chains as an integral part of BSC. This shortcoming can be explained with one theoretical and one practical reason[Blumenberg and Hinz, 2006]. From a theoretical point of view, causalities within the BSC method and their application are only vaguely described by Kaplan and Norton. From a practical consideration, modeling corporate causalities is a complex task due to tedious data acquisition and following reliability maintenance. However, cause-and effect relationships are an essential part of BSCs because they differentiate performance measurement systems like BSCs from simple key performance indicator(KPI) lists. KPI lists present an ad-hoc collection of measures to managers but do not allow for a comprehensive view on corporate performance. Instead, performance measurement system like BSCs tries to model the relationships of the underlying value chain in cause-and-effect relationships. Therefore, to overcome the deficiencies of causal modeling in IT BSC, sound and robust causal modeling approaches are required in theory as well as in practice for offering a solution. The propose of this study is to suggest critical success factors(CSFs) and KPIs for measuring performance for IT organizations and empirically validate the casual relationships between those CSFs. For this purpose, we define four perspectives of BSC for IT organizations according to Van Grembergen's study[2000] as follows. The Future Orientation perspective represents the human and technology resources needed by IT to deliver its services. The Operational Excellence perspective represents the IT processes employed to develop and deliver the applications. The User Orientation perspective represents the user evaluation of IT. The Business Contribution perspective captures the business value of the IT investments. Each of these perspectives has to be translated into corresponding metrics and measures that assess the current situations. This study suggests 12 CSFs for IT BSC based on the previous IT BSC's studies and COBIT 4.1. These CSFs consist of 51 KPIs. We defines the cause-and-effect relationships among BSC CSFs for IT Organizations as follows. The Future Orientation perspective will have positive effects on the Operational Excellence perspective. Then the Operational Excellence perspective will have positive effects on the User Orientation perspective. Finally, the User Orientation perspective will have positive effects on the Business Contribution perspective. This research tests the validity of these hypothesized casual effects and the sub-hypothesized causal relationships. For the purpose, we used the Partial Least Squares approach to Structural Equation Modeling(or PLS Path Modeling) for analyzing multiple IT BSC CSFs. The PLS path modeling has special abilities that make it more appropriate than other techniques, such as multiple regression and LISREL, when analyzing small sample sizes. Recently the use of PLS path modeling has been gaining interests and use among IS researchers in recent years because of its ability to model latent constructs under conditions of nonormality and with small to medium sample sizes(Chin et al., 2003). The empirical results of our study using PLS path modeling show that the casual effects in IT BSC significantly exist partially in our hypotheses.

• 대한안전경영과학회지
• /
• 제8권6호
• /
• pp.149-157
• /
• 2006

This paper suggests the design and operation of value stream mapping(VSM) applied to project management, such as R&D, IT Investment. First this study represents design methodology of VSM process using SIPOC(Supplier, Input, Process, Output, Costumer). Second, this paper considers the identification and improvement plan about non-added value time for VSM using FPC(Flow Process Chart) and PERT/CPM. Last, this paper proposes VSM scheduling method using PERT/CPM and CCPM(Critical Chain Project Management)