• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.663-669
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• 2011

In this study, the optimal length of left-turn lane in permissive left-turn signal system at the signalized intersection which has a left-turn bay is estimated. It is a simulation analysis using the queueing theory that estimate the length of left-turn lane. Traffic density conform to the standards of operating a permissive left-turn system of the Practical Manual Traffic Safety Facilities. And each of a left-turn arrival rate, a left-turn service rate, left-turn average queueing time, for green time average queueing vehicle, for red time average queueing vehicle and average queueing vehicle cycle is calculated. As a result of this study, we would learn how much the space should be secured at the signalized intersection which has a left-turn bay. The methodology using the queueing theory to work out the optimal length of waiting lane in the permissive left-turn signal system was presented.

• Korean Journal of Construction Engineering and Management
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• v.10 no.2
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• pp.84-92
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• 2009

Recently, lots of the research aspects of space, materials, structure, construction method relation to improving the flexibility going on throughout the construction industry, moreover the development of construction key technology has been accelerating by reason of deterioration in the apartment housing. Therefore, this study should firstly suggests assessment list of construction key technology through investigation of questionnaire and consultation of the expert on the basis of case studies, and should select it about the flexibility which making social issues lastly in the apartment housing. Secondly, this study should classify, reestablish core technology through inspection procedure of feasibility study among lists of deduced key technology. Finally, this study will suggest the manual & guideline for improving the flexibility for a long-life apartment housing at the next generation by selecting, analyzing and estimating higher score items of all key technology.

• Physical Therapy Korea
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• v.9 no.4
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• pp.1-11
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• 2002

본 연구의 목적은 이중과업 방법론(dual task methology)을 사용해서 젊은 사람과 노인을 대상으로 독립된 두 사건(two separate concurrent events)을 동시에 수행하는데 요구되는 주의력에 대한 분석과 노인에서의 특징적 차이를 찾는 것이다. 본 실험은 대상자가 힘판(force plate) 위에서 장애물(10cm) 보행시에 경피자극(cutaneous stimulation)에 대하여 마이크로 스위치(micro-switch)를 사용하여 반응하면서 시행되었다. 힘판과 시간(temporal events) 그리고 반응시간(reaction time)에 관한 자료들은 1000 Hz의 주파수로 수집되었다. 반응시간은 대상자들이 서 있는 상태(baseline) 장애물 보행시(dual task)에서 수집되었다. 반응시간은 아중과업 조건에서 대상자 모두에게서 긴 것으로 나타났으며 특히 노인에서 정상 성인보다 반응시간이 긴 것으로 나타났다. 이중과업 조건 하에서 노인 대상자가 정상 성인에 비해 발가락이 장애물에 닫지 않고 통과할 수 있는 공간, 즉 토우 클리어런스( toe-clearance)와 슬관전 굴곡(knee flexion) 각도가 훨씬 큰 것으로 나타났다. 이중과업 조건하에서 모든 대상자가 족관절 배측굴곡(ankle dorsiflexion) 각도를 감소시키는 것으로 나타났다. 노인들은 젊은 대상자들보다 훨씬 더 긴(124 ms) 유각시간을 보여 주었으며 정상 장애물 보행시 유각 시간은 이중과업보다 50 ms 긴 것으로 나타났다. 이러한 보행 특성의 차이는 노인대상자들이 젊은 대상자들보다 장애물 보행시에 이중과업의 영향을 더 받았기 때문인 것으로 판단된다. 이중 과업 시행시 이러한 토우 클리어런스의 감소와 장애물 통과시에 보행 속도의 증가는 아마도 낙상의 가능성을 증가시키는 요인이 될 수 있는 것으로 보여진다. 본 연구의 결과는 다중과업(multitasks)을 필요로 하는 보행 훈련 프로그램(gait training program)의 개발과 시행에 있어서 기초적인 자료를 제공할 수 있는 것으로 보여진다.

• Tunnel and Underground Space
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• v.29 no.3
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• pp.135-147
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• 2019

This paper introduced a impact load estimation method by examining vibration transfer path analysis (TPA). The theoretical background and the load quantification procedure are explained, and a case study of hydraulic breaker is reported. We explained the merits and limitations of the load estimation method of TPA, and improvement method was suggested through case analyses of drilling equipment. The necessity of R&D of load-estimation technology was discussed. A new strategy for developing new techniques for impact load measurement was proposed.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.5
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• pp.70-83
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• 2023

Recently, the Korea Forest Service has implemented a planning project about wind corridor forests as a response measure to climate change. Based on this, research on wind corridors has been underway. For the creation of wind corridor forests, a preliminary evaluation of the wind corridor function is necessary. However, currently, there is no evaluation index to directly evaluate and spatially distinguish the types of wind corridors, and analysis is being performed based on indirect indicators. Therefore, this study proposed a method to evaluate and classify wind corridors by utilizing heat deficit analysis as an evaluation index for cold air generation. Heat deficit was analyzed using a cold air analysis model called Kaltluftabflussmodell_21 (KLAM_21). According to the results of the simulation analysis, the wind path was functionally classified. The top 5% were classified as cold-air generating Areas (CGA), and the bottom 5% as cold-air vulnerable Areas (CVA). In addition, the cold-air flowing Areas (CFA) were classified by identifying the flow of cold air moving from the cold air generation area. It is expected that the methodology of this study can be utilized as an evaluation method for the effectiveness of wind corridors. It is also anticipated to be used as an evaluation index to be presented in the selection of wind corridor forest sites.

• Journal of the Korean Geographical Society
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• v.29 no.2
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• pp.202-215
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• 1994

This research aims to introduce the theoretical basis of the studies of tourism resources, by review the research trends of tourism resources in the geography field. The geographical approaches to tourism resouces can be subdicided into 3 categories according to the subject. First, the classification of tourism resource types and the approach on the spatial distribution may be enumerated. This subject has been the object of the most interest and discussion to the geographers for tourism up to now. And from the viewpoint of contents, it has been developed by classifying the types of tourism resoures, which is based on the establishment of the range and standard of tourism resources and the spatial classification of types based on the distribution feature of the area. Second, the approach about cognition, preference and interpretation on the tourism resources as the background to induce tourism phenomenon and decide the tourism destination. Judging from the fact that most of this subject is starting from the behavioural study and that the right understanding and interpretation of tourism resource is the important factor to decide the preference degree of tourists, we have to have much interest about the field of tourism geoaraphy. Third, the development of tourism resources which is showing the active study recently and its influence and effect attendant upon it may be enumerated. Today, as the economic value of tourism is become important internationally, tourism resources are recognized as the important factor to induce the industrialization of tourism. And in the series of analytical studies related to it the interest has been transferred from the economic benefit analysis attendant upon tourism development including tourism resource and to the cultural, educational, environmental and psychological influence, etc. As the result of composite examination, for the geographical studies about tourism resources, the spatial scale and the contents are being subdivided and specialized. And in the side of subject and method of study, it is developing into the positive study based on the concrete data and the measuring and analytical frame.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.105-113
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• 2010

This study is for the preservation plan of the tradition space which is performed by the damage status analysis through performing the value assessment. Especially, it is an experimental study for finding the process and methods by analyzing the major element for the value assessment of the selected object's damage status through the expert group who are systematized in their interest to conserve the traditional structure in traditional space. For that purpose, this study should be performed by the fundamental understanding of the physical property of the Supyo-bridge and the condition of the selected site's environment. Meanwhile, this study has been done that 'map of the damage status distribution' for making records of damage status of the Supyo-bridge on the property utilized field measurement adapted by photogrammetry and assessment guidelines, which are for investigation on damage status of objects that are standardized 'Raccomandazioni Normal' which could be said construction culture assets management guidelines of Italian government. As the result of investigation, damage status of each part in the Supyo-bridge was mostly composed of damage by sediment and corrosion and in case of 9 damage types including corrosion, in consideration of physical and chemical properties and distribution status of those elements, it is made an judgement that is not working as a threatened factor regarding security of the Supyo-bridge. On the contrary, for the improvement landscape, in case of 'Thermoclastism' phenomenon observed in 'upper floor', 'Myungae stone' and 'bridge pier' is that when taking it into consideration that is widely distributed concentrated on the bridge pier, surface reinforcement job along with elimination of damage part will be judged to be requested for earliest treatment.

• Korean Journal of Remote Sensing
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• v.30 no.5
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• pp.651-664
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• 2014

Recently, the demands of accurate forest carbon stock estimation and mapping are increasing in Korea. This study investigates the feasibility of two methods, k-Nearest Neighbor (kNN) and Regression Tree Analysis (RTA), for carbon stock estimation of pilot areas, Gongju and Sejong cities. The 3rd and 5th ~ 6th NFI data were collected together with Landsat TM acquired in 1992, 2010 and Aster in 2009. Additionally, various vegetation indices and tasseled cap transformation were created for better estimation. Comparison between two methods was conducted by evaluating carbon statistics and visualizing carbon distributions on the map. The comparisons indicated clear strengths and weaknesses of two methods: kNN method has produced more consistent estimates regardless of types of satellite images, but its carbon maps were somewhat smooth to represent the dense carbon areas, particularly for Aster 2009 case. Meanwhile, RTA method has produced better performance on mean bias results and representation of dense carbon areas, but they were more subject to types of satellite images, representing high variability in spatial patterns of carbon maps. Finally, in order to identify the increases in carbon stock of study area, we created the difference maps by subtracting the 1992 carbon map from the 2009 and 2010 carbon maps. Consequently, it was found that the total carbon stock in Gongju and Sejong cities was drastically increased during that period.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.163-172
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• 2011

Purpose : The purpose of this study was to review our recent experiences with deep neck abscesses in children and adolescents and to provide helpful information in treatment and diagnosis by comparing them with those in other available literatures. Methods : Medical records of 36 children and adolescents admitted for deep neck abscess at two hospitals from January 2000 to October 2010 were reviewed retrospectively. Results : Male to female ratio was 1.4 : 1 and the mean age was 6.5 years. Painful neck swelling and fever were the most frequent symptoms in patients under thirteen years of age whereas trismus and headache were frequent symptoms in patients over fourteen years of age. Submandibular space was the most common site of deep neck abscess in patients under thirteen years of age, whereas peritonsillar space was the most common site in patients over fourteen years of age. The results of bacterial cultures were positive in 61.5% of drained cases. Staphylococcus aureus was the most commonly identified bacteria in 6 patients (37.5%) and 5 of them were under 2 years of age. Twenty six patients received surgical drainage while the others were treated with antibiotics only. There were no statistically significant differences in the durations of admission, fever after admission, and antibiotic treatment between surgical and medical treatment groups. Conclusion : The common sites of deep neck abscess, associated symptoms, and causative organisms were different between children and adolescents. As there were no differences in durations of admission, fever, or antibiotics treatments between surgical and medical treatment groups, surgical drainage may be avoided by early recognition and suspicion. However, if there is no improvement of symptoms or size of abscesses within 48-72 hours of antibiotic treatment, surgical drainage should be considered.

• Land and Housing Review
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• v.12 no.3
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• pp.11-26
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• 2021

With the increasing demand for office space, there have been questions on how office rent distribution produces a change in the urban spatial structure in Seoul. The purpose of this paper is to investigate a relative price gradient and to present a time-series model that can quantitatively explain the dynamic changes in the urban spatial structure. The analysis was dealt with office rent above 3,306 m² for the past 10 years from 1Q 2010 to 4Q 2019 within Seoul. A modified repeat sales model was employed. The main findings are briefly summarized as follows. First, according to the estimates of the office price gradient in the three major urban centers of Seoul, the CBD remained at a certain level with little change, while those in the GBD and the YBD continued to increase. This result reveals that the urban form of Seoul has shifted from monocentric to polycentric. This shows that the spatial distribution of companies has gradually accelerated decentralized concentration implying that the business networks have become significant. Second, contrary to small and medium-sized office buildings that have undertaken no change in the gradient, large office buildings have seen an increase in the gradient. The relative price gradients in small and medium-sized buildings were inversely proportional among the CBD, the GBD, and the YBD, implying their heterogeneous submarkets by office rent movements. Presumably, those differences in the submarkets were attributed to investment attraction, industrial competition, and the credit and preference of tenants. The findings are consistent with the hierarchical system identified in the Seoul 2030 Plan as well as the literature about Seoul's urban form. This research claims that the proposed method, based on the modified repeat sales model, is useful in understanding temporal dynamic changes. Moreover, the findings can provide implications for urban growth strategies under rapidly changing market conditions.