• Journal of the Korea Safety Management & Science
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• v.2 no.2
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• pp.187-200
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• 2000

The charge and discharge current in EPR(Ethylene Propylene Rubber), which were irradiated with the radiant capacity of 0~600 ［kgy/h］, have been measured in order to investigate the influence of the atmosphere (oxygen, air and vacuum) on electrical properties. It has been shown that the charge and discharge current increase as the amount of radiant capacity increases in air and vacuum atmosphere. This electrical property degradation can be speculated due to that the C＝O radicals or impurities, which comes from during shaping process, may act as dipoles. On the other hand, the charge and discharge current are shown to be higher in the amount of 1［kgy/h］ than these in 10［kgy/h］ in air atmosphere, because the charge and discharge current can be increased as the exposure time is extended with slower rate. Under the same amount of irradiation, the charge and discharge current in oxygen atmosphere are shown to be higher than those in vacuum. This is possibly due to that the main chain can be broken by oxidation when it is exposed to the $\gamma$ -rays.

• Journal of Internet Technology
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• v.20 no.1
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• pp.301-313
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• 2019

In this paper, we propose a new MAC protocol for Cognitive Radio (CR)-based IoT networks, called MSMA/CA. We extend the standard CSMA/CA, adopted in IEEE 802.11 WLANs, to the CR networks with the minimal modification since it works well in the real world. We resolve the classical hidden/exposed terminal problems by a variant of RTS/CTS mechanism and further, the hidden primary terminal problem by the mutual spectrum sensing at the transmitter and the receiver. We also modify the backoff process of CSMA/CA to incorporate the blocking of secondary transmitters, with the aim of protecting ongoing primary transmissions from aggressive secondary users. We analyze the throughput and delay of our proposed scheme using the Markov chain model on the backoff procedure, and verify its accuracy by simulations. Simulation results demonstrate that our protocol is suitable for IoT networks since the performance is insensitive to the number of users or devices.

• Journal of Korea Port Economic Association
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• v.38 no.3
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• pp.151-164
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• 2022

According to the "2021 Trade Statistics" released by the Korea Customs Service, the number of domestic export companies has decreased by 2,400 since COVID-19, and the number of importers has increased by 10,000. Exporting companies are making a great contribution to the economic development of Korea along with the creation of domestic jobs. At a time when the logistics environment changes rapidly, there are insufficient papers analyzing the impact of eco-friendly logistics strategies of domestic exporters on logistics performance. In order for exporting companies to continue to have global competitiveness and improve logistics performance, it is necessary to analyze the impact of eco-friendly logistics strategies on the logistics performance of exporting companies. The purpose of this study is to analyze the effect of eco-friendly logistics strategies of domestic export companies on logistics performance. The eco-friendly logistics strategy is divided into an internal strategy and a supply chain management strategy. As a result of the analysis, it was analyzed that the internal strategy has a positive effect on the logistics performance of exporting companies, and the supply chain management strategy has a positive effect on the logistics performance of exporting companies. As such, it was analyzed that the eco-friendly logistics strategy of exporting companies is an important resource for companies and serves as the basis for improving the logistics performance of companies.

• Journal of the Korea Safety Management & Science
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• v.22 no.1
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• pp.45-50
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• 2020

The number of elevators in Korea has surpassed 700,000 units in 2019, which is the 8th in the world by number of installed units and 3rd in the world by new units. The word 'lift' is a representative word, and the category includes elevators, escalators, dumb waiters, and moving walks. Those who live in the city will experience using elevators once or twice a day, and these elevators are becoming an indispensable means of transportation when using high-rise apartments or subways. However, such a convenient elevator also has a lot of risks that threaten the safety of the user and actually cause many accidents every year. In particular, escalators (including moving walks), which account for as little as 5% of all elevators, account for 70% of all elevator accidents. According to Heinrich's chain of thought theory, accidents are caused by a combination of factors, which are divided into five stages: Stage 1: Genetic Factors and Social Environment, Stage 2: Individual Defects, Stage 3: Unsafe behavior and Unsafe conditions, Stage 4: Accident, Stage 5: Injury. Heinrich said that three of these five phases, unsafe behavior and unsafe conditions, require safety management and efforts to prevent accidents. In escalator accidents, the analysis of accident cases that have occurred so far will be related to unsafe behaviors and unsafe conditions, and the effective management of these causes of accidents will enable safer and more convenient use of escalators. This study analyzed accident cases of elevator users, focusing on escalator accidents over the last 10 years (2010 ~ 2019), and safety management to prevent safety accidents of elevator users by analyzing the behavior of actual users and questionnaires of experts in related fields. The method was studied.

• Journal of Information Technology Services
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• v.23 no.1
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• pp.1-10
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• 2024

The IT environment is changing due to the acceleration of digital transformation in enterprises and organizations. This expansion of the digital space makes centralized cybersecurity controls more difficult. For this reason, cyberattacks are increasing in frequency and severity and are becoming more sophisticated, such as ransomware and digital supply chain attacks. Even in large organizations with numerous security personnel and systems, security incidents continue to occur due to unmanaged and unknown threats and vulnerabilities to IT assets. It's time to move beyond the current focus on detecting and responding to security threats to managing the full range of cyber risks. This requires the implementation of asset Inventory for comprehensive management by collecting and integrating all IT assets of the enterprise and organization in a wide range. IT Asset Management(ITAM) systems exist to identify and manage various assets from a financial and administrative perspective. However, the asset information managed in this way is not complete, and there are problems with duplication of data. Also, it is insufficient to update of data-set, including Network Infrastructure, Active Directory, Virtualization Management, and Cloud Platforms. In this study, we, the researcher group propose a new framework for automated 'Comprehensive IT Asset Management(CITAM)' required for security operations by designing a process to automatically collect asset data-set. Such as the Hostname, IP, MAC address, Serial, OS, installed software information, last seen time, those are already distributed and stored in operating IT security systems. CITAM framwork could classify them into unique device units through analysis processes in term of aggregation, normalization, deduplication, validation, and integration.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2007.02a
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• pp.146-149
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• 2007

2000년대에 접어들어 컴퓨터가 보급화 되면서, 컴퓨터를 도구로 하는 범죄가 폭발적으로 증가하기 시작하였다. 컴퓨터 시스템에 접근하여 중요 정보를 빼돌리거나, 범죄의 목적이 되는 해킹과 같은 정보보호 침해사고가 크게 증가하였으며, 컴퓨터를 이용한 정상적인 서비스를 방해하는 형태의 디지털 범죄들이 다수 발생하기 시작하였다. 따라서 범죄 수사 과정에서 전자 매체에 대한 분석이 필수 불가결한 요소로 등장하고 있으며, 이를 분석하려는 디지털 포렌식 연구가 활발히 진행되고 있다. 특히 전자 매체에 기록되는 디지털 정보는 보관이 편리하지만 삭제와 복제가 용이하므로 디지털 증거는 매우 세심하게 다루어야 하며, 수사관에 의한 의도적인 훼손이 없었음을 증명할 수 있는 절차와 제도가 필요하다. 국내에서는 적법한 수사 절차와 무결성을 보장하기 위하여 '절차 연속성(chain-of-custody)'을 제공하는 수사 가이드라인을 제작하였으며, 체계적인 수사를 수행 하고 있다.[4] 이와 더불어 포렌식 수사 과정에서 물리적인 접근을 통해 디지털 저장 매체에 대한 복구할 수 있는 방법이 존재하며, 이에 대한 구체적인 방안을 논한다.[1]

• International Journal of Highway Engineering
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• v.19 no.5
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• pp.1-11
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• 2017

PURPOSES : This study is aimed at development of a stochastic pavement deterioration forecasting model using National Highway Pavement Condition Index (NHPCI) to support infrastructure asset management. Using this model, the deterioration process regarding life expectancy, deterioration speed change, and reliability were estimated. METHODS : Eight years of Long-Term Pavement Performance (LTPP) data fused with traffic loads (Equivalent Single Axle Loads; ESAL) and structural capacity (Structural Number of Pavement; SNP) were used for the deterioration modeling. As an ideal stochastic model for asset management, Bayesian Markov multi-state exponential hazard model was introduced. RESULTS:The interval of NHPCI was empirically distributed from 8 to 2, and the estimation functions of individual condition indices (crack, rutting, and IRI) in conjunction with the NHPCI index were suggested. The derived deterioration curve shows that life expectancies for the preventive maintenance level was 8.34 years. The general life expectancy was 12.77 years and located in the statistical interval of 11.10-15.58 years at a 95.5% reliability level. CONCLUSIONS : This study originates and contributes to suggesting a simple way to develop a pavement deterioration model using the total condition index that considers road user satisfaction. A definition for level of service system and the corresponding life expectancies are useful for building long-term maintenance plan, especially in Life Cycle Cost Analysis (LCCA) work.

• Journal of Construction Engineering and Project Management
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• v.3 no.2
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• pp.1-12
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• 2013

Research indicates that good front-end planning (FEP) results in the achievement of higher levels of project performance. By facilitating collaboration among stakeholders in diverse locations with the use of workflow-enabled processes, such pressures can be reduced, and the overall process and results of FEP can be improved. With these goals, a front-end planning tool (FEPT) has been developed as support for owners and major contractors who are engaged in front-end planning. This paper presents the new FEPT and describes how it has been used for construction megaprojects in the nuclear power, oil and gas, and mining industries. The paper begins with the definitions related to and an explanation of the general process for implementing and applying the FEPT and then describes and analyzes how the FEPT was applied in case study projects in order to test its validity. The results indicate that the FEPT increases the efficiency and effectiveness of front-end planning for the megaprojects studied and that it has the potential to produce similar results for other megaprojects.

• Industrial Engineering and Management Systems
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• v.7 no.1
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• pp.57-65
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• 2008

Available-to-promise (ATP) exhibiting availability of manufacturing resources can be used to support customer order promising. Recently, one advanced function called Capable-to-promise (CTP) is provided by several modern APS (advanced planning system) that checks available capacity for placing new production orders or increasing already scheduled production orders. At the customer enquiry stage while considering the order delivery date and quantity to quote, both ATP and CTP are allocated to support order promising. In particular, current trends of mass customization and multi-side production chain derive several new constraints that should be considered when ATP/CTP allocation planning for order promising - such as customer's preference plants or material vendors, material compatibility, etc. Moreover, ATP/CTP allocation planning would be executed over a rolling time horizon. To utilize capacity and material manufacturing resource flexibly and fulfill more customer orders, ATP/CTP rolling planning should possess resource reallocation mechanism under the constraints of order quantities and delivery dates for all previous order promising. Therefore, to enhance order promising with reliability and flexibility to reallocate manufacturing resource, the ATP/CTP reallocation planning mechanism is needed in order to reallocate material and capacity resource for fulfilling all previous promised and new customer orders beneficially with considering new derived material and capacity constraints.

• Journal of Internet Computing and Services
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• v.3 no.5
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• pp.1-8
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• 2002

Because XML is a W3C standard and has characteristics like platform-independent, it has a critical role in e-commerce. Business rules and procedures should be standardized for efficient B2B integration, But a lot of companies are its own XML documents instead of standard document, Therefore many organizations try to make standards for e-commerce based on framework. Also, in case use supply chain administration system, because document transmit between corporation use on-line, need messaging system that can transfer XML message In this paper, XML messaging system is designed and implemented. Client requests service in XML and server returns response in XML in this system, So we con more easily and efficiently to exchange document between company this XML messaging system.