• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.2
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• pp.1-14
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• 1998

The purpose of this study is to find out how the urban landscape of Korea, especially Seoul, changed during the last half century since 1945. The modernization of Korea, which had begun in 1960's after the chaotic period caused by Korean War, influenced the rapid growth of cities and the radical changes of its structures. But the Western-minded planning theories based on rationalism and positivism was directly applied in developing our traditional cities and consequently the modern urban landscape including urban pattern, architectural style, and commercial and residential landscape revealed disharmony, discrepancy and inconsistency in skylines, streetscape and so on. The findings are summarized as follows. 1. Because the urban structure and pattern changed in undesirable manner in terms of land use and traffic circulation, cities as a whole resulted in exclusive and heterogeneous landscape, and citizens lost their identity and felt alienated. 2. Because the architectural forms of important and monumental buildings which influenced the character of streetscape were not so successful in inventing contemporary Korean Style in true sense, we still have difficulty in creating the urban landscape of originality and legibility. 3. Because from the beginning of this era almost all highrise buildings were designed by modernism-oriented western architects, the commercial landscape of central cities did not evoke a sense of place, and after the introduction of postmodernism this tendency is ore striking even in everyday ordinary streetscape. 4. The newly formed residential landscape which was mainly composed of highly dense and highrise apartment, not only evolved very overwhelming and ugly visual impact but also exposed many social problems in living condition, neighboring and face-to-face contact. In conclusion, in ordr to define the 'Koreanness' of our urban landscape, we have to struggle to combine traditional architectural heritage and native townscape with Western shape, thought and theory, no matter how difficult it may be.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.360-363
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• 2007

In sensor network, the importance of transporting data with reliability is growing gradually to support communications. Data flow from sink to nodes needs reliability for the control or management, that is very sensitive and intolerable, however relatively, data flow from nodes to sink is tolerable. In this paper, with emphasis of the data flow from sink to nodes, we proposed the mechanism that establishes confidence interval for transport. Establishing confidence interval hop-by-hop, not end to end, if errors happen or there's missing data, this mechanism recovers them with selective acknowledgement using fixed window. In addition, this mechanism supports traffic congestion control depending on the buffer condition. Through the simulation, we showed that this mechanism has an excellent performance for error recovery in sensor network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.11
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• pp.979-985
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• 2012

The design of an efficient scheduler is a key design factor in IEEE 802.16m systems, in order to support services with various QoS smoothly. Although conventional studies of schedules have been suggested, those had problems that are not able to satisfy the delay condition and make the through-put declined, because they only focused on a specific action scenario rather than reflecting practical action scenarios which have real-time and non-real-time traffics variously. In this paper, an efficient uplink scheduling algorithm is proposed for IEEE 802.16m system by introducing the concepts of Virtual Time(VT) and Virtual Finish Time(VFT) based priority determination, and separate buffers for each QoS class in the mobile terminal. Simulation results showed that the proposed scheme had satisfied the delay requirement of real-time services even with improved throughput performance compared to conventional methods.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.1024-1029
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• 2009

According to increase of massive concrete structures, Thermal crack done by heat of hydration have been increased in a process of the execution. In case of a subway concrete box structure, thickness of structures are almost over 1 meter, and penetrating crack by external restraint takes a bad effect on the durability with a water leakage and deterioration in especially concrete wall. A try of shortening a constructing period often occurs as subway is generally constructed according to a road to decrease a traffic jam. The research proposes executing method by skipping one block as a plan of shortening a constructing period and investigate an influence on thermal cracking control. Additionally, sensitivity analysis is accomplished by changing a height of a concrete wall, and concrete placing and air temperature met with a field condition.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.123-132
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• 2011

The purpose of this study is to calculate and propose rational multi-lane loading factors for bridge design considering the probability of simultaneous truck passing in adjacent lanes and real truck weights. The probability of simultaneous truck passing is calculated by analyzing video image taken at various locations in highways and national roads. Weigh-In-Motion system data at two locations are used, which is combined with the probability of multiple presence to calculate the multi-lane loading factors for typical 2 lane and 5 lane bridges. Statistical properties of multi-lane loading factors are also calculated assuming that locations for video images and WIM data represent the overall traffic condition in the country. Results are compared with various design codes in the world and they show that the values are between the current Korea Bridge Design Code and AASHTO LRFD specification or Eurocode and are similar to Canadian Code.

• Journal of Korean Society of Rural Planning
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• v.23 no.2
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• pp.55-65
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• 2017

This study is to estimate the circuity factors which can be used to assess for public facilities accessibility and analyze traffic in the area. We set the range of the administrative districts by Si Gun Gu unit and Eup Myeon Dong unit (more subdivided unit than Si Gun Gu unit). The average circuity factor in Si Gun Gu unit is 1.364 (maximum 2.953 and minimum 1.711). The region indicated the highest value of circuity factor is wando-gun in jeollanam-do, which area consists of 4 island and is connected to the bridges. Having to use the bridges for using public facilities hinders its accessibility. In the case of Eup Myeon Dong unit, the average circuity factor is 1.353 (maximum 2.950 and minimum 1.154). The region indicated the highest value of circuity factor is buksan-myeon in chuncheon-si, Gangwon-do. This region also has to use bridges for using public facilities because there is the largest lake, called Soyangho. This circuity factor is used to analyze the location of public facilities and assess vulnerability of accessibility. And also the factor can be applied to some policies, such as rural public service planning based on spatial big data.

• Journal of Korean Society of Transportation
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• v.18 no.4
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• pp.31-39
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• 2000

Cellular Phone use while driving is one of the critical causes of traffic accident by falling the driver into the improper lookout and inattention situations by disturbing the driving behaviors and by increasing the driver's mental workloads. These days, therefore, governments in many countries are trying to Prohibit the cellular Phone use while driving by the law focused on the hand-held type of cellular phone. This Paper investigated the impacts on the hands-free cellular Phone use while driving to the drivers Performance among normal and two different level of secondary task driving conditions in the urban of Japan. As the results, quantitative differences of drivers eye movement, subjective mental workload, steering wheel angle entropy, and cognitive Performance of secondary tasks were compared between straight and curve (right turn) section for each driving condition.

• Journal of Korean Society of Transportation
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• v.22 no.1 s.72
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• pp.19-30
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• 2004

Once baggage demand of passengers is forecast, BHS requirements must be analyzed, i.e., the number of originating/transferring/terminating bags to be handled, the number of conveyor lines to be installed, the number of containers for baggage make-up, the number of claim devices for baggage claim, and so on. Therefore, the determination of the baggage traffic volume is one of the most important analysis components for the airport design. Accordingly, this research proposes time-based distribution table models in order to accurately estimate BHS requirements to obtain design criteria in airport design phase. As the BHS requirements are ascertained, related requirements of the facilities can be determined by applying actual specifications of devices, i.e., throughput. This research found that the proposed mathematical model gives a good reflection of IIA (Incheon International Airport)'s operational condition. That means the model provides apparent reliability and feasibility. Furthermore, the specifications of devices are the newest figures. This fact supports that the research provides more effcient and reliable results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.31-36
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• 2020

The LTE-R system is a system consisting of a packet network that provides all IP-based services. Continuous failures related to the platform safety gate and subsequent safety accidents related to passengers and safety gate workers continue. The secondary damage caused by the failure of the platform safety door and the related human life damage have emerged as a major social issue.. By linking the beacon system to the Long Term Evoluton-Railway (LTE-R) network, an LTE-based railway wireless network currently in operation or being installed, it precisely locates trains and provides standardized fault alerts to train crews. When entering into the station, ultimately we will decelerate the train and reduce the accidents of metropolitabn railroad traffic by securing safe driving.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.113-120
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• 2010

Video proxy server which is located near clients can store the frequently requested video data in storage space in order to minimize initial latency and network traffic significantly. However, due to the limited storage space in video proxy server, an appropriate video selection method is needed to store the videos which are frequently requested by users. Thus, we present a time constraint multiple access technique to efficiently store the video in video proxy server. If the video is requested by user, it is temporarily stored during the predefined interval and then, delivered to the user. A video which is stored is deleted or moved into the storage space of video proxy server depending on the request condition. In addition, we propose a video deletion method in video proxy server for newly stored video data. The simulation results show that the proposed method performs better than other methods in terms of the block hit rate and the number of block deletion.