• Journal of the Korea Institute of Construction Safety
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• v.2 no.2
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• pp.50-55
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• 2019

Currently, safety management is becoming important at domestic construction sites. Despite the importance of safety management, accidents at construction sites are steadily increasing. Fire accidents among safety accidents cause not only negative effects on schedule delay or work plans at construction sites, but also huge casualties. Therefore, the purpose of this research is to extract the causes of fire at the construction site through the case of fire at the construction site, and to prioritize prevention through the analysis of the factors to contribute to the prevention of fire. As a research method, we select fire factors through case, conduct surveys through expert group, and analyze survey through AHP technique. The results of the AHP analysis of the survey of expert groups showed that the workers and their sub-item ranked high. Therefore, the priority for fire prevention was given, and this research is believed to help prevent fire.

• Journal of Information Technology Services
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• v.18 no.5
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• pp.209-224
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• 2019

When evaluating the performance of a NPD(New Product Development) project, it is common to evaluate the project performance according to the achievement of the planned goal in terms of time, quality and cost management, which are usually three main constraints of the project. The evaluation of the financial factors by which sales contributed to the return of the company is more influential. This is why companies need to increase sales and raise profits. Therefore, it is more reasonable to evaluate the sales performance of NPD projects over a certain period of time against the input costs. At this time, we can analyze the causes of inefficient projects and compare them with other projects and find out how to improve the sales performance to help the company increase its competitiveness. In this paper, we analyze the relative efficiency of the sales performance on the input of the projects by using the actual sales in the period of one year after mass production of the NPD projects of 'S' company in ICT industry. Input factors include developer resource and development cost for the NPD reported after the project has been completed, the delay weeks for the schedule targeted at the project planning stage, and the number of quality issues due to development design faults during initial mass-production. The sales figure and the contribution margin of the product after one year from the start of mass production are defined as the output factors. In this paper, we analyze the efficiency of the projects by using data envelope analysis (DEA). As a result, we found out the reason of the inefficient project of DMUs according to the differences in the characteristics of the efficient and inefficient B2B markets based on the result of DEA of NPD projects. Thus, the goal of this paper is to identify strategies for improving sales performance of NPD projects in inefficient markets.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.61-72
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• 2018

Conflicts in public construction projects lead to increase social costs as well as construction costs and schedule delay. Therefore, it is important to evaluate the conflict in construction project and find appropriate solutions based on previous cases. In this research, the conflict factors and criteria for evaluating conflict are derived and 30 cases are evaluated by 11 conflict experts. Using k-means clustering, the cases are clustered by three clusters. The cases were analyzed according to the characteristics of each cluster and labeled as 'NIMBY and harmful facility conflict cluster', 'environmental and pollution conflict cluster', and 'PIMFY and small conflicts'. In the future, when conflict occurs in the public construction projects, the conflict can be evaluated using this clustering and the characteristics of the conflicts can be found. As a result, it will be helpful to mitigate the conflict quickly and effectively by looking for previous cases that are suitable for resolving the conflict through appropriate clusters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3309-3328
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• 2017

The application of Internet of Things (IoT) in the next generation cellular networks imposes a new characteristic on the data traffic, where a massive number of small packets need to be transmitted. In addition, some emerging IoT-based emergency services require a real-time data delivery within a few milliseconds, referring to as ultra-low latency transmission. However, current techniques cannot provide such a low latency in combination with a mice-flow traffic. In this paper, we propose a dynamic resource reservation schema based on an air-interface slicing scheme in the context of a massive number of sensors with emergency flows. The proposed schema can achieve an air-interface latency of a few milliseconds by means of allowing emergency flows to be transported through a dedicated radio connection with guaranteed network resources. In order to schedule the delay-sensitive flows immediately, dynamic resource updating, silence-probability based collision avoidance, and window-based re-transmission are introduced to combine with the frame-slotted Aloha protocol. To evaluate performance of the proposed schema, a probabilistic model is provided to derive the analytical results, which are compared with the numerical results from Monte-Carlo simulations.

• Convergence Security Journal
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• v.15 no.4
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• pp.3-9
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• 2015

A web application that allows a web service created by a internal developer who has security awareness show certain level of security. However, in the case of development by outsourcing, it is inevitable to implement the development centered on requested function rather than the issue of security. Thus in this paper, we improve the software testing process focusing on security for exclusion the leakage of important information and using an unauthorized service that results from the use of the vulnerable web application. The proposed model is able to consider security in the initial stage of development even when outsourced web application, especially, It can prevent the development schedule delay caused by the occurrence of modification for program created by programer who has low security awareness. This result shows that this model can be applied to the national defense area for increasing demand web application centered resource management system to be able to prevent service of web application with security vulnerability based on high test.

• Sleep Medicine and Psychophysiology
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• v.3 no.2
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• pp.65-76
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• 1996

Natural sleep pattern and its physiology in childhood are much different from those in adulthood. Several aspects of clinical evaluation for sleepiness in childhood are more difficult than in adulthood. These difficulties are due to several factors. First, excessive sleepiness in childhood do not always develop functional impairments. Second, objective test such as MSLT may not be reliable since it is hard to be certain that the child understand instructions. Third, sleepiness in children is often obscured by irritability. paradoxical hyperactivity, or behavioral disturbances. Anseguently, careful clinical evaluation is needed for the sleepy children. Usual causes of sleepiness in children are the disorders that induce insufficient sleep such as sleep apnea syndrome, schedule disorder, underlying medical and psychiatric disorder, and so forth. After excluding such factors, we can diagnose the hypersomnic disorders such as narcolepsy, Kleine-Levin syndrome, and idiopathic central nervous system hypersomnia. Among the variety of those causes of sleepiness, I reviewed the clinical difference of narcolepsy and obstructive sleep apnea syndrome in childhood compared with in adulthood. Recognition of the childhood narcolepsy is difficult because even severely sleepy children often do not develop pathognomic cataplexy and associated REM phenomena until much later. Since childhood narcolepsy give srise to many psychological, academical problem. Practicers should be concerned about these aspects. Childhood obstructive sleep apnea syndrome is different from adult obstructive sleep apnea syndrome too. Several aspects such as pathophysiology. clinical feature, diagnostic criteria, complication, management, and prognosis differ from those in the adult syndrome. An important feature of childhood obstructive sleep apnea syndrome is the variety of severe complications such as behavioral disorders, cognitive impairment, cardiovascular symptoms, developmental delay, and ever death. Fortunately, surgical interventions like adenotosillectomy or UPPP are more effective for Childhood OSA than adult form. CPAP is a "safe, effective, and well-tolerated" treatment modality too. So if early detection and proper management of childhood OSA were done, the severe complication would be prevented or ever cured.

• Korean Journal of Construction Engineering and Management
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• v.2 no.3 s.7
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• pp.101-109
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• 2001

Application of system form is very effective to continuous horizontal or vertical walls of the apartment housing. Though the system forms that are used in the construction field have the advantage of concrete quality improvement and increasing number of usages, there are some problems in reaching early planning scheduling goal due to schedule delay and low productivity. This study is initiated to solve the problem and suggest some improvements searching for reasons that diminish the productivity. A case study was done in apartment construction field where system form was used and the productivity is analyzed by work sampling. Finally, productivity improvements for assembly of the form, internal form and external form are suggested, respectively.

• Korean Journal of Construction Engineering and Management
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• v.6 no.6 s.28
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• pp.181-192
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• 2005

Labor work information can be converted into the useful construction information in an effort to analyze project status, measure performance, and design a new similar project plan. The labor work information can also be used to make productivity data, which can be used to analyze the relationship between 'as planned' and 'as built' in scheduling management of a project, and to calculate 'percent completion' as well as analyzing delay cause. It is require to effectively collect the labor work information base on the activities. In general, current project management heavily depends on the experience and judgment of project managers, according to the work progress. However, relying on the oかy experience and judgment of the project managers might deteriorate the transparency or reliability of the collected labor work information. The purpose of this research is thus to develop a computer-based system for monitoring the work information generated by labors input in activities using PDA and Barcode technologies, and to propose a application method of the productivity data for effective project management.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.213-216
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• 2007

The paper deals with a approach to underwater acoustic based Ad-hoc communication, which allows major design strategies for Media Access Control (MAC) within a group of the autonomous underwater vehicles(AUV). The proposed MAC aims at deploying AUV-centric star topology, which minimizes overhead of sensor nodes and improves energy-efficiency. Furthermore, that is also well under long and unknown propagation delays of the underwater acoustic medium. The implemented MAC protocol makes it easier to achieve frame synchronization than TDMA due to deploying localized schedule time, in addition to saving energy consumption by letting nodes sleep. It is also superior to MACA and MACAW in terms of propagation delay. This scalable centralized protocol has the potential to serve as a primer for development of MAC protocol for future underwater acoustic based ad-hoc networks.

• IE interfaces
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• v.16 no.spc
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• pp.99-104
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• 2003

While demands for express service are rapidly increasing according to recent progress of electronic commerce, express service companies are struggling to take a larger delivery service market share through ongoing improvement in their service processes. Extension of cut-off time for express service centers can provide the express company with increase of total sales, but it may also cause to increase the possibility not to satisfy customer needs due to work delay in the consolidation terminal. Therefore, compromised decision for cut-off time of each service center should be made by taking operation characteristics of the consolidation terminal into account. This study suggests an approach for determining the cut-off time for express service centers according to operational characteristics of the consolidation terminal with the objective of maximizing expected incremental sales. The problem defined in this study can be represented as two successive models; one is an integer programing model in which the best cut-off time for each sales center are determined, and the other is a single machine scheduling model in which a working schedule in the consolidation terminal is obtained. A genetic algorithm is developed to solve the two models simultaneously. Finally, an example problem is carried out to verify applicability and performance of the algorithm with the data set collected from an express company.