• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.203-208
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• 2011

Traffic demand is continuously increasing due to the development of urban areas in Korea. To cope with this, many efforts have been done including constructions of new roadways and increasing the number of lanes of the existing roadways. Those efforts, however, have been performed for only a short segment of target links having similar traffic characteristics. As a result, most urban cities experience bottle-neck phenomena which lead decreasing flow speed and increasing possibilities of accidents. Thus, this study aims to analyze problems of bottle-neck phenomena and effects of balancing number of lanes along the same corridor having similar traffic characteristics. For this, Route 32 passing the city of Daejeon in Korea has been selected as a case study, and a micro-simulation tool, VISSIM, has been adopted for the analysis. The results show that balanced number of lanes along the same corridor with similar traffic characteristics can increase flow speeds and enhance safety.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.346-353
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• 2011

Routing schemes that service applications with various delay times, maintaining the long network life time are required in wireless sensor & actor networks. However, it is known that network lifetime and hop count of trees used in routing methods have the tradeoff between them. In this paper, we propose a Pareto Ant Colony Optimization algorithm to find the Pareto tree set such that it optimizes these both tradeoff objectives. As it enables applications which have different delay times to select appropriate routing trees, not only satisfies the requirements of various multiple applications but also guarantees long network lifetime. We show that the Pareto tree set found by proposed algorithm consists of trees that are closer to the Pareto optimal points in terms of hop count and network lifetime than minimum spanning tree which is a representative routing tree.

• Journal of KIISE:Databases
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• v.29 no.2
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• pp.119-127
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• 2002

Video server which stores video streams should serve more users with the requested streams rapidly, satisfying their time constraints. However, the number of users supported and the response times for the requested services in video server are in the oppositional relationship with viewpoint of disk throughput. In this paper, we propose new policy that can provide not only rapid responses for the service requests but also increase the number of users supported in the storage system of video server. The policy admits the random movements of disk heads for urgent service requests but maintains the sequential or restricted movements of disk heads and eliminates rewind time of disk heads for less-urgent service requests in storage system of multiple disks environment so that it can not satisfy only the QoS of users but also support more users.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.45-58
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• 2021

It is generally known that a two-lane roundabout has some problems in safety such as increasing conflicts, typically merging and diverging conflicts and conflicts between entering traffic and exiting as well as turning traffic. To solve these problems, a turbo-roundabout had been developed and has successfully brought safer and more efficient operation in other countries. In this study, micro simulations using VISSIM were conducted to investigate the maximum value of service traffic volume. It was found that operation of turbo-roundabouts was influenced by traffic volume for each turning traffic, and the maximum values of traffic volume were values between 2,400 and 2,800 vehicles per hour as rates of traffic volume for each turning traffic. Typically, turbo-roundabouts have limited to operate in conditions with more than 30% for left-turning traffic volume.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.879-885
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• 2018

The highway weaving section is a point where there is a conflict caused by entry and exit vehicles. In order to minimize the impact on the main line, an accumulation line should be installed. The design speed of the collecting part is 50 km/h, but the actual driver does not have proper deceleration according to the design speed. In this study, considering the driving behaviors, the design specification, and the driver 's viewing angle, the appropriate separation distance for safe entry and exit of collecting, connecting, and collecting roads was examined. As a result of the analysis, it is found that a distance of 60m is required from the point where the merging starts. The results of this study are expected to contribute to the improvement of driver safety due to the conflict between entry and exit vehicles when applied to the weaving section where collecting roads are installed.

• 한국사회정책
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• v.23 no.3
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• pp.1-15
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• 2016

This article aims to find Karl Marx's views on the social policy and to reorganize them into a systematic social policy theory. His views on the welfare state are scattered in diverse works including Capital and Communist Manifesto, and are very complicated and sometimes contradictory. This article further aims to reinterpret his contradictory views on social policy and to attempt to show what he really meant on social policy. By so doing, this article will contribute to re-establishing Karl Marx's status in the field of social policy study. Karl Marx's social policy theory is one of the least researched area in social policy, although several Western scholars introduce and evaluate his views on the welfare state in social policy textbooks and articles. In particular, it is very difficult to find a work attempting to reorganize and reinterpret Karl Marx's contradictory views on social policy. In this regard, this article deserves a significant academic concern.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.786-794
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• 2020

For systematic pet management, the pet registration system has established. It makes the owner of the pet is given greater responsibility through the pet registration system but it also provided with welfare. One of the advantages of the pet registration system is that prepare system what return to owner quickly and safety through information inquiry when the pets are lost. But there are some conflict with the law in the information inquiry, so it occurs interfere the system. In this paper, we propose using the Smart Contract to finding the missing animal effectively. Proposed method discloses only the partially information. Thus it will be eliminated conflict parts, and increases the information accessibility to increase the number of people who can inquiry information. In addition, keeping the RFID inquired feature for compatible with the existing system. The smart contract querying enables quickly and precision access to information. Lastly, compare the proposed method with existing method to see the improvement.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.707-714
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• 2021

An important factor that causes delays at roundabouts is unbalanced traffic conditions. The majority of domestic studies have tendedto focus on the proportion of entering traffic rather than conflicting traffic in order to explain unbalanced traffic conditions. Also, there is scant research on the proper distance between a signalized intersection and a roundabout. In this study, therefore, unbalanced traffic conditions and optimal distance between two intersections were analyzed using SIDRA software based on the Gajwa-ro roundabout in Icheon, where unbalanced traffic conditions occur during afternoon peak hours, and its position is 295 m from a signalized intersection. It was found that a state of unbalanced traffic conditions in the form of conflicting traffic caused delays at Gajwa-ro roundabout, and the queuing length on each approach was removed when there was 850 m of distance between two intersections.

• Land and Housing Review
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• v.13 no.3
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• pp.107-113
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• 2022

With increasing airtight building construction aimed at reducing energy consumption, indoor relative humidity is increasing which can lead to condensation and moisture damage in multi-family residential buildings. This has led to increased implementation of mechanical ventilation to control indoor moisture. However mechanical ventilation systems consume additional energy and generate noise. As this leads to occupant discomfort, it is necessary to select a ventilation system that addresses the energy and noise issues. This research measured the ventilation performance, energy consumption, and noise level of mechanical ventilation devices in multi-family residential buildings. TOPSIS, a multi-criteria decision making technique was used to determine appropriate ventilation strategies in addition to occupant ventilation system operation preference.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.448-462
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• 2021

Only a few studies investigated the relationship between exchange structure and solidarity in online communities and even reported conflicting results. This study attempts to shed lights on this relationship by introducing a moderating variable, i.e., exchange benefits, based on the social exchange theory. Also, distributed knowledge is considered as a determinant of exchange structure. The results of a field study from 380 online communities show that both direct and generalized exchange structures have positive effects on community solidarity, but their effects vary depending on the level of exchange benefits. When exchange benefits are high, generalized exchange influences community solidarity more than direct exchange does, whereas at a low level of benefits there are no significant differences between the two exchange structures. Also distributed knowledge turns out to be a significant influencer of generalized exchange.