• Wind and Structures
• /
• 제5권5호
• /
• pp.463-478
• /
• 2002

Lighting and traffic signal columns are mainly stressed by excitation due to natural, gusty wind. Such columns typically have a door opening about 60 cm above ground level for the connection of the buried cable with the column's electric system. When the columns around this notch are inadequately designed, vibrations due to gusty winds will produce considerable stress amplitudes in this area, which lead to fatigue cracks. To give a realistic basis for a reliable and economic design of lighting and traffic signal columns, a number of experimental and theoretical investigations have been made. The proposed design concept allows the life of such columns to be assessed with a satisfactory degree of accuracy.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
• /
• pp.635-642
• /
• 1997

This research focused on the development of concrete overlay and test, which was conducted at 88 Highway 105k, 2 lanes of 290 m. The field application test consists of 6 cm and 10 cm bonded concrete overlay and 25 cm unbonded concrete overlay, using the slag cement for opening lanes for traffic early. The overlay were placed in a day. The whole period of traffic closing wes 8 day and it was reopened to traffic after concrete overlay has cured for 3 day. 5 cracks were founded when the field test section was investigated after 1 month, but all these may not make significant problems to overlay because these initiated and growed at the same line of repair section. The rideability and skid resistance become much better like in the new pavement after overlay. The structural capacity against deflection was much. which were verified by FWD(Falling Weight Deflectometer). The field test section is being used in a good condition and the results of field application and pavement performance analysis are encouraging. This rehabilitation methods may be adopted in Korea after a more field performance verifications.

• 대한교통학회지
• /
• 제32권6호
• /
• pp.589-599
• /
• 2014

본 논문에서는 개통연도 예측 교통량과 개통 후의 실제 교통량의 비교를 통해 교통량 예측 오차를 분석하였다. 분석 결과, 역별 개통연도 교통량(승 하차 인원)의 평균오차(I)는 7.27수준인 것으로 분석되었다. 또한 지역별로 오차가 상이하고 공사기간이 장기간이거나 역간거리가 짧아지면 교통량 과다 추정 오차가 증가하는 것으로 분석되었다. 따라서 도시철도사업이 정해진 계획대로 정해진 기간 안에서 진행될수록 교통예측 오차를 줄일 수 있을 것으로 판단된다. 이외에도 수요예측연도가 최근일수록 오차가 줄어드는 것으로 나타났다. 향후 추진될 도시철도 신규 노선에 대해서는 지금까지의 도시철도 이용객 추정의 오차와 경향을 바탕으로 보다 정확하고 현실적인 이용객 추정이 필요하다. 본 논문의 한계점은 초기연도의 오차에 대해서만 분석하였고 오차발생 변수도 외생변수에 국한하여 분석한 점이다. 향후에는 오차발생에 대해서 다양한 변수를 대상으로 검토되어야 할 것이다.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 1999년도 추계학술대회논문집
• /
• pp.91-99
• /
• 1999

In Pusan Harbour, new port development projects are implemented such as the Extended Terminal adjacent to the Gamman Terminal, Pusan New Port, the Nary $\infty$ piers, etc. which will require new marine traffic environments in the Passage I of Pusan Harbour Specially, the turning basin of the Extended Terminal adjacent to the Gamman Terminal gas been designed to overlay the Passage I of Pusan Harbour, Which will interrupt the inbound traffic flow and the results will be worried to decrease the efficiency of port operation. Therefore, this paper will be aimed to evaluate the traffic congestion in the Pusan Passage I due to the opening of new ports within Pusan Harbour in 2006 and 2011 by using computer simulation based the queueing theory.

• 한국대기환경학회지
• /
• 제24권2호
• /
• pp.153-161
• /
• 2008

The guidelines for indoor air quality of public transportations such as subway, train and bus was presented by Korean Ministry of Environment last end of year 2006 based on the great consequence of indoor air quality in daily life. Two main parameters, carbon dioxide($CO_2$) and particulate matters smaller than $10\;{\mu}m(PM_{10})$, were selected as index pollutants for the management of indoor air quality. The former pollutant, $CO_2$, is regarded as index of ventilation status and the major source of $CO_2$ in the train or subway is the exhalation of passengers. It is publically perceived that the high $CO_2$ concentration in a crowded subway will be reduced and ventilated with outdoor air by door-opening taken every 2 or 3 minutes when the train stops each station. However, there has not been any scientific proof and quantitative information on the effect of door-opening on the $CO_2$ reduction by ventilation with outdoor air. In this study, $CO_2$ concentration and number of passengers were measured at each station on the 3 lines of Korail metropolitan subway. In order to evaluate the effect of $CO_2$ reduction by door opening, the theoretical approach using the $CO_2$ balance equation was performed. By comparing the predicted data with monitoring one, the optimum $CO_2$ dilution factor was determined. For the first time, it was quantified that about 35% of $CO_2$ concentration in the subway indoor was removed by the door-opening at each station.

• 한국경제지리학회지
• /
• 제22권4호
• /
• pp.576-591
• /
• 2019

본 연구는 경기 이남의 역세권과 구도심에 위치한 '롯데몰 수원점'을 사례로 위계선형-이중차분법을 활용하여 거리 접근성이 권선구 내 주변 아파트가격에 미친 효과를 분석한다. 이에 대한 분석 결과는 다음과 같다. 첫째, 공사 이전에는 거리 접근성 효과가 U자형을 보여주고 있다. 이는 수원역 주변의 소음과 교통 혼잡 등에 따른 부정적 외부효과가 권선구 내 주변 아파트가격에 부정적인 영향을 미쳤다는 것을 시사한다. 둘째, 공사 기간과 개점 이후 등 상이한 시점에 따른 거리 접근성 효과는 후자에서만 통계적으로 유의하며 개점 이전과는 달리 역 U자형을 나타내고 있다. 이는 개점 이후에는 복합쇼핑몰과 근거리 구간에서는 그것이 여가·편의공간으로 인식되는 외부효과가 권선구내 주변 아파트가격에 긍정적인 영향을 미치고 있다는 것을 의미한다. 셋째, 거리 접근성 효과는 약 1.6-1.7km 내외에서 변곡점을 이루고 있다. 공사 이전에는 U자형의 거리조락 현상을, 반면에 개점 이후에는 역 U자형의 패턴을 보여주고 있다. 후자는 복합쇼핑몰과 매우 인접한 권선구 내 아파트들이 상대적으로 적은 정(+)의 외부효과를 향유한다는 것, 즉 이들은 소음과 교통 혼잡의 부정적인 외부효과에 일정 정도 노출되어 있지만 거리가 어느 정도 떨어진 권선구내 아파트들은 이러한 정(+)의 외부효과를 극대화하고 있다는 것을 함의한다. 이러한 분석 결과들은 전체적으로 복합쇼핑몰에 대한 거리 접근성 효과가 입지별로 차별적이라는 것을 시사한다.

• 한국항해항만학회지
• /
• 제42권5호
• /
• pp.357-364
• /
• 2018

Colombo noticeably became the most economical gateway to the Indian subcontinent, in terms of cost as well as time. The Colombo Port Expansion Project (CPEP) started commencement with the purpose of accommodating mega ships, under the long-term strategies of making Colombo the hub of South Asia. In this context, the purpose of this study is to investigate the causal relationship between Indian ports' originated container traffic, and total transshipments of the port of Colombo, and also to identify the nature of the causality between the two variables, evaluating Granger causality test results. It finds unidirectional causality from total transshipments of Colombo to Indian ports' originated transshipments in the port of Colombo. It suggested that ongoing port expansion projects, opening up for new markets and attracting new shipping lines in the port of Colombo, have generated significant impact on Indian ports' container traffic, via the port of Colombo. Findings would be valuable for future forecasting of container traffic in Colombo port and the policy-making process in the port as well.

• 한국분무공학회지
• /
• 제21권4호
• /
• pp.214-222
• /
• 2016

Changes in road infrastructure affect driving patterns and pollutant emission characteristics. we analyzed the changes in driving patterns and pollutant emission characteristics of the driving route via measured driving patterns at year 2009 and 2016. Since 2009, there has been an increase in population and traffic demand, including residential areas and industrial facilities. Traffic conditions were improved such as the opening of the highway Inter-Change to Seoul and the construction of underground driveway. As a result, the average vehicle speed increased. More detail comparisons have made on the changes of the underground driveway section and the crossroad section, which are expected to have significant changes in the transportation infrastructure. The vehicle speed distribution of the underground driveway changed from low speed to high speed, and the increase of the time spent at the high speed and high load caused the increase of NOx emissions. The vehicle speed also increased at the crossroad section, and the consequence NOx and $CO_2$ emissions decreased. It is mainly because the decreased time spent at idle, which results from the proper traffic demand management at this area.

• Structural Engineering and Mechanics
• /
• 제19권3호
• /
• pp.347-359
• /
• 2005

This paper attempts to develop the analytical model of estimating the fatigue damage using a linear elastic fracture mechanics method. The stress history on a welding member, when a truck passed over a bridge, was defined as a block loading and the crack closure theory was used. These theories explain the influence of a load on a structure. This study undertook an analysis of the stress range frequency considering both dead load stress and crack opening stress. A probability method applied to stress range frequency distribution and the probability distribution parameters of it was obtained by Maximum likelihood Method and Determinant. Monte Carlo Simulation which generates a probability variants (stress range) output failure block loadings. The probability distribution of failure block loadings was acquired by Maximum likelihood Method and Determinant. This can calculate the fatigue reliability preventing the fatigue failure of a welding member. The failure block loading divided by the average daily truck traffic is a predictive remaining life by a day. Fatigue reliability analysis was carried out for the welding member of the bottom flange of a cross beam and the vertical stiffener of a steel box bridge by the proposed model. Results showed that the primary factor effecting failure time was crack opening stress. It was important to decide the crack opening stress for using the proposed model. Also according to the 50% reliability and 90%, 99.9% failure times were indicated.

• PNF and Movement
• /
• 제21권3호
• /
• pp.273-280
• /
• 2023

Objective: In patients with temporomandibular joint disorders, air insoles are used to investigate functionality and pain changes in the temporomandibular joint when walking in daily life. Intervention: Sixty-five patients with temporomandibular joint disorder were recruited: 34 as a control group who walked more than 7,000 steps a day in daily life, and 31 as an experimental group who were instructed to take at least 7,000 steps every day while wearing their air insoles. Measurements: To determine the effects of air insoles on temporomandibular joint pain, steady-state pain, maximum mouth opening, average pain, and the most severe pain were measured before and after the experiment. In addition, to evaluate functionality, the ability to open the mouth in a comfortable state, pain when opening the mouth, and the point of sound and maximum degree to which the mouth could be opened were evaluated before and after the experiment. Results: Pain, mouth openness, and sound points showed significant differences from the control group after the experiment, and the maximum mouth opening range showed no significant difference. Conclusion: When air insoles were used by patients with temporomandibular joint disorder, the functionality of the temporomandibular joint was improved and pain was decreased.