• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3678-3698
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• 2017

With the rapid development of vehicular ad hoc Network (VANET), it has gained significant popularity and received increasing attentions from both academics and industry communities in aspects of security and efficiency. To address the security and efficiency issues, a self-authentication and deniable efficient group key agreement protocol is proposed in this paper. The scheme establishes a group between road side units (RSUs) and vehicles by using self-authentication without certification authority, and improves certification efficiency by using group key (GK) transmission method. At the same time, to avoid the attacker attacking the legal vehicle by RSUs, we adopt deniable group key agreement method to negotiation session key (sk) and use it to transmit GK between RSUs. In addition, vehicles not only broadcast messages to other vehicles, but also communicate with other members in the same group. Therefore, group communication is necessary in VANET. Finally, the performance analysis shows superiority of our scheme in security problems, meanwhile the verification delay, transmission overheard and message delay get significant improvement than other related schemes.

• Fire Science and Engineering
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• v.22 no.5
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• pp.9-21
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• 2008

The objective of this study is to suggest a fire prevention measure for suppressing and preventing loss of precious human lives and property damages. The characteristics of incendiary fire are analyzed in terms of fire engineering to review a plan for promoting for coping with the risk. In this study, a medical aspect such as mental and psychological analysis of the motive or act of an incendiary and legal and administrative problems such as the penalty for the incendiary are not included in the scope of the study. Fire statistics data of Korea, Japan, and U.S. are investigated for analysis of actual states of incendiary fire occurrences. In particular, to quantitatively recognize the burning characteristics of common fire and the burning characteristics of incendiary fire, a fire model test and computer simulation were performed. And a plan for promoting the optimal incendiary fire prevention measure were suggest.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.113-121
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• 2015

This study aims to examine the risk of electrical fire in places where electric heat wires are used. In general, the use of electric heating wires is becoming more common and prevalent in a bid to prevent increasing damage caused by freezing and bursting in residential water pipes, factory pipes and irrigation pipes in vinyl greenhouse and a variety of heat wire products are available in market with legal safety requirements imposed on them. However, the widespread use of anti-freezing burst heat wire products has caused increasing incidents of fire, which often fail to be incorporated into statistics due to quick onsite extinguishing and insignificant damage although damage is gradually on the rise. Against this backdrop, this study aims to look into the possibility of ignition caused by electric heat wires and the mechanism of how it turns into catching fire through overheat and short circuit tests for anti-freezing burst electrical heat wires (hereinafter called the 'heat wire') and expects to serve as the basis for further observations and analyses on the cause of fire and the process of ignition in a scientific manner.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.2
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• pp.49-54
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• 2013

In field of apartment housing currently, insulation technology is the most effective way because it is common to improve the thermal performance, therefore, it is contributed to energy saving as several regional insulation standards and legal mandate method. In addition, by applying of building energy efficiency rating certification system, it has inspired voluntary energy conservation commitment for the building owner or facility manager by making a plan to evaluate and verify building energy performance. However, these circumstances are not enough to acquire a grade 2 of higher information. Therefore, in this study, we analyzed the impact of building energy efficiency rating and confirmed reduction ratio compared to the standard housing on the basis of recent our nation building law when we had changed the shape of windows and wall insulation performance and shapes of housing.

• Journal of Internet Computing and Services
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• v.20 no.3
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• pp.61-68
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• 2019

The goal of the construction work in the past was to improve the efficiency through cost reduction and shortening the construction period. However, the importance of safety management has recently been emphasized, and the Ministry of Employment and Labor has set a goal of reducing the number of deaths caused by industrial accidents by half. As a result, institutional and legal improvements are pursued and the need for safety is emphasized. However, most construction companies, except for some large construction companies, are lacking in safety management. So, In this paper, we design and implement a safety management system for construction site using smart helmets and beacons.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.227-228
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• 2014

In this paper, a license plate investigation which is one of parking usage is performed. We survey research that should be given time interval using the camera without the observer. We assigned the investigation time interval to each of to each of the parking car, average parking duration is determined. Parking turnover, the number of vehicles of parking per hour per parking surface, is examined.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.205-207
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• 2014

This paper uses $Color-x^2$ histogram that is composed of merits of color histogram and ones of histogram, in order to efficiently extract violent scenes in elevator. Also, we use a threshold so as to find out key frame, by use of existing $Color-x^2$ histogram. To increase the probability that discerns whether a real violent scene or not, we take advantage of statistical judgments with 20 sample visual images.

• Journal of Information Processing Systems
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• v.17 no.6
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• pp.1057-1070
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• 2021

Case-related news filtering is crucial in legal text mining and divides news into case-related and case-unrelated categories. Because case-related news originates from various fields and has different writing styles, it is difficult to establish complete filtering rules or keywords for data collection. In addition, the labeled corpus for case-related news is sparse; therefore, to train a high-performance classification model, it is necessary to annotate the corpus. To address this challenge, we propose topic-enhanced positive-unlabeled learning, which selects positive and negative samples guided by topics. Specifically, a topic model based on a variational autoencoder (VAE) is trained to extract topics from unlabeled samples. By using these topics in the iterative process of positive-unlabeled (PU) learning, the accuracy of identifying case-related news can be improved. From the experimental results, it can be observed that the F1 value of our method on the test set is 1.8% higher than that of the PU learning baseline model. In addition, our method is more robust with low initial samples and high iterations, and compared with advanced PU learning baselines such as nnPU and I-PU, we obtain a 1.1% higher F1 value, which indicates that our method can effectively identify case-related news.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.437-446
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• 2005

Recently as people's values are changing from development phase into running stage after quality of life, so that the needs of environmentally friendly construction are gradually increasing. Also populace discontent about the pollution during construction process such as the noise and vibration caused by construction machinery is increasing. Even though it is impossible to eliminate the construction pollution fully, it is necessary to make efforts to reduce construction pollution to a minimum. In terms of construction site operating, the first possible step for solving these matters directly is that the necessary sum of expenses must be secured as the environmental management costs in the conceptual phase. However, in fact, the environmental management costs have not been secured in the budget. Generally it is the major reason not arising proper activities to prevent the pollution in the construction site. The purpose of this research is to suggest the efficient budgeting method regarding Environmental management costs to ensure the necessary sum of environmental management expenses. To provide an efficient budgeting method, interviews with the person in charge of environment management was conducted. 78 construction sites was surveyed and environmental management costs were analyzed through their historical data from the survey. According to the results of analysis, the ratio of environmental management costs is revealed 0.45% of construction cost as average comparing 0.2% of legal limit. And usually the environmental management cost was appropriated into the safety management budget. So it is needed to isolate environmental management budget securely and modify the ratio of Environmental conservation Costs in Construction Technology Management Act.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.551-562
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• 2022

The building production system has been analysed by the dichotomy "employer-contractor" relationship, which failed to take into account of the role and function of multiple stakeholders within the life-cycle supply chain. This is further observed in the current conflict resolution model, which, in my argument, struggles to contribute to industrialize the building production and achieve better efficiency and effectiveness as expected. The purpose of this paper is to critically assess the issues of current programme-based conflict resolution model, and discuss alternative models how they can be modelled and applied to the construction projects. The conclusions of findings are; First, the current model is framed around the contracts and dispute resolutions based on the legal concept of "claimant and respondent" where one party(s) advances a claim once and the other(s) objects, as such it fails to reflect the nature of construction projects where multiple stakeholders are involved concurrently and for a long period of life-cycle of buildings. Second, an alternative is "Six-stakeholders model" which represents the multiple stakeholders and clarifies the flow of obligation-liability-monetary relationships among participants for a long period of life-cycle of buildings. Further, with reference to both historical and recent cases, a reflection and insight into pros and cons of programming method is added, especially as to why this method is considered to have become a mandate of the modern construction management, and how academics and practitioners should deal with it more cautiously and prudently.