• Smart Structures and Systems
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• v.29 no.4
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• pp.549-560
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• 2022

The optimum damping and tuning frequency ratio of the tuned mass damper-inerter (TMDI) for the base-isolated structure is obtained using the numerical searching technique under stationary white-noise and filtered white-noise earthquake excitation. The minimization of the isolated structure's mean-square relative displacement and absolute acceleration, as well as the maximization of the energy dissipation index, were chosen as the criteria for optimality. Using a curve-fitting technique, explicit formulae for TMDI damping and tuning frequency for white-noise excitation are then derived. The proposed empirical expressions for TMDI parameters are found to have a negligible error, making them useful for the effective design of base-isolated structures. The effectiveness of TMDI and its optimum parameters are influenced by the soil condition and isolation frequency, according to the comparison made of the optimized parameters and response with different soil profiles. The effectiveness of an optimally designed TMDI in controlling the displacement and acceleration response of the flexible isolated structure under real and pulse-type earthquakes is also observed and found to be increased as the inertance mass ratio increases.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.506-513
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• 2009

The Construction Industry Institute (CII) developed the Project Definition Rating Index (PDRI), as a part of their Front End Planning best practices, which helps project managers assess and measure project scope definition risk elements. U.S. Green Building Council are seeing the benefits of sustainable building and Leadership in Energy and Environmental Design certification by positively impacting life cycle costs, building marketability, and organizational productivity. However, there have been no efforts to integrate these two planning tools in construction industry. By applying a supplemental tool which combines the PDRI with the LEED rating system, construction industry can develop and implement a tailored instrument that leads to total project success in sustainability. The objective of this research is to assemble a new front end planning mechanism for green buildings by incorporating the current PDRI and LEED systems.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.3
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• pp.147-155
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• 1997

Optimal trajectory for a robot manipulator minimizing actuator torques or energy consumptions ina fixed traveling time is obtained in the presence of obstacles. All joint displacements are represented in finite terms of Fourier cosine series and the coefficients of the series are obtained optimally by nonlinear programming. Thus, the geometric path need not be prespecified and the full dynamic model is employed. To avoid the obstacles, the concept of the penalty area is newly introduced and this penalty area is includ- ed in the performance index with an appropriate weighting coefficient. This optimal trajectory will be useful as a geometric path in the minimum-time trajectory planning problem.

• Steel and Composite Structures
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• v.47 no.1
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• pp.121-134
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• 2023

This paper tested 11 concrete-encased concrete-filled steel tube (CFST) composite columns and one reinforced concrete column under combined axial compression and lateral loads. The primary parameters, including the loading system, axial compression ratio, volume stirrup ratio, diameter-to-thickness ratio of the steel tube, and stirrup form, were varied. The influence of the parameters on the failure mode, strength, ductility, energy dissipation, strength degradation, and damage evolution of the composite columns were revealed. Moreover, a two-parameter nonlinear seismic damage model for composite columns was established, which can reflect the degree and development process of the seismic damage. In addition, the relationships among the inter-story drift ratio, damage index and seismic performance level of composite columns were established to provide a theoretical basis for seismic performance design and damage assessments.

• Journal of the Korean Society of Food Culture
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• v.25 no.6
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• pp.755-763
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• 2010

The purpose of this study was to select market variables that a foodservice company should consider when expanding overseas and to regional market analysis by variables. Twenty-three different variables were derived from 17 previous studies. These were: population, urbanization rate, women employed, enrollment in tertiary education, gross domestic product, value added by service, total number of mobile cellular telephone subscribers, number of internet users, total Asian highway, inward foreign direct investment, total service imports, inflation rate, international tourist arrivals, energy use by industry, growth rates of the food consumer price index, access to urban sanitation, per capita total expenditure on health, male life expectancy at birth, adult literacy rate, contributing women family workers, passenger car, and country risk assessment. The selected variables were collected as secondary data from the UN, Asian Development Bank, International Bank for Reconstruction and Development, and Michigan State University.

• Journal of Trauma and Injury
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• v.36 no.4
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• pp.416-420
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• 2023

Blunt intrathoracic tracheal injuries are rare, even among blunt chest trauma patients. An early diagnosis based on a high index of suspicion allows for timely surgical management of potentially fatal airway trauma, thereby improving overall outcomes. Diagnosing these injuries can be difficult due to their nonspecific clinical features and the occasional difficulty in radiologic diagnosis. If a patient exhibits respiratory compromise with difficult ventilation and poor lung expansion, despite the insertion and management of an intercostal drain following high-energy blunt trauma, there should be a heightened suspicion of potential airway trauma. The aim of primary repair is to restore airway integrity and to minimize the loss of pulmonary parenchyma function. This case report discusses the rare clinical presentation of a patient with blunt trauma to the intrathoracic airway, the surgical management thereof, and his overall outcome. Although blunt traumatic injuries of the trachea are extremely rare and often fatal, early surgical intervention can potentially reduce the risk of mortality.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.167-168
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• 2023

에너지분야 국가핵심기반시설에서 산업재해 및 업무중단 사고예방을 위해 재해경감활동관리체계(BCMS)에서 일일위험지수 재난안전관리 프로그램을 자체개발 운용하여 정부의 중대재해 감축 로드맵의 핵심적인 4대 전략 중 하나인 사업장에서 유해위험요인에 대한 자기규율적인 예방관리체계의 확립한 사례를 제시하였다. 이에 대한 신뢰성 검증을 위해 중대산업재해 감축효과에 영향을 미친 사업장의 BCMS, 일일위험지수 및 중대재해처벌법 간의 관계성을 연구한 결과, 제도 간 개념의 관련성이 높으며, 상호 보완적이고 영향을 미치는 것으로 확인되었다. 따라서 동종 사업장에서 재해경감활동관리체제의 일일위험지수를 활용한다면 중대재해예방관리에 도움이 될 것으로 기대된다.

• Geomechanics and Engineering
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• v.38 no.6
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• pp.593-601
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• 2024

In this paper, the quantitative evaluation method is presented for the durability performance of mountain tunnel concrete linings experiencing freezing and thawing during winter season. To analyze the freeze-thaw characteristics of lining, the freezing time of the concrete lining was measured by the outside temperature. The heat flow analysis was conducted based on the freezing time measured through the indoor experiment, and based on this, the energy required to freeze the concrete lining by the temperature of the outside air could be analyzed. In addition, the temperature change during the winter season was measured through an instrument installed on the actual tunnel concrete lining, and based on the results of indoor and field experiments, criteria for freeze-thaw environment evaluation and progress evaluation were prepared. Also, an equation using the freezing index was proposed through regression analysis.

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.1
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• pp.47-51
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• 2010

Purpose: In the treatment of high-energy protons Air gap (the distance between the patient and the exit Beam) Lateral Penumbra of the changes to the increase in the radiation fields can form unnecessary and Increase the maximum dose at the site of treatment and reduced the minimum dose homogeneity of dose distributions can decline. Air gap due to this change in dose distribution compared to investigate studied. Materials and Methods: Received proton therapy at our institution Lung, Liver patients were selected and the size of six other Air gap in Field A and Field B 2, 4, 6, 8, 10 cm Proton external beam planning system by setting up a treatment plan established. Air gap according to the Lateral Penumbra area and DVH (Dose Volume Histogram) to compare the maximum dose and minimum dose of PCTV areas were compared. In addition, the dose homogeneity within PCTV Homogeneity index to know the value and compared. Results: Air gap (2, 4, 6, 8, 10 cm) at each change in field size were analyzed according to the Lateral Penumbra region Field A Change in the Air gap 2~10 cm by 1.36~1.75 cm, the average continuously increased about 28.7% and Field B Change in the Air gap 2~10 cm by 1.36~1.75 cm, the average continuously increased about 31.6%. The result of DVH analysis for relative dose of the maximum dose According to Air gap 2~10 cm is the mean average of 110.3% from 108.1% to a sustained increased by approximately 2.03% and The average relative dose of minimum dose is the mean average of 93.9% percent to 90.8 percent from the continuous decrease of about 3.31 percent. The result of Homogeneity index value to the according to Air gap 2~10 cm is the 2-fold increase from 1.09 to 2.6. Conclusion: In proton therapy case, we can see the increasing of lateral penumbra area when airgap getting increase. And increasing of Dmax and decreasing Dmin in the field are making increase homogeneity index, So we can realize there are not so good homogeneity in the PCTV. Therefore we should try to minimize air gap in proton therapy case.

• Korean Journal of Health Education and Promotion
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• v.23 no.5
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• pp.1-11
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• 2006

Objectives: The 2003 WHO/FAO technical report described that Korea has largely maintained its traditional high-vegetable diet despite major social and economic changes, and had lower than expected levels of obesity prevalence than other industrialized countries. However, the prevalence of obesity in Korea has recently been rapidly increasing. The aim of this study was to elucidate the determinants of this rapid growth of obesity prevalence in Korea and to compare the results of national nutrition surveys between Korea and Japan. Methods: The trends of the National Health and Nutrition Survey in Korea instituted every 3 years and that in Japan conducted every year were compared. The results of obesity prevalence defined as more than 25 of the Body Mass Index, the percentage of habitual exercisers and the results of the nutritional surveys were examined from 1992 to 2005 in Korea and from 1992 to 2004 in Japan. Results: The prevalence of obesity in males has been gradually increasing in both Korea and Japan since 1992. Though until 1995 the prevalence of obesity in the Korean male population was less than that in Japan, after 1998 Korea surpassed Japan and a markedly increasing trend was observed. In females, the increasing trend of obesity was slower than males in both Korea and Japan. However, the prevalence of obesity was much higher in Korea compared with that in Japan. The percentage of exercisers was much lower in Korea than in Japan. Although, the definition of an exerciser varies with the survey year in Korea and is different from that in Japan, almost 70% of the population was not regularly engaging in moderate or hard intensity exercise in Korea. From 1995, the total energy intake was increased by 9.8% in Korea but it was decreased by 6.9% in Japan. Presently, the energy intake per capita per day in Korea exceeded that in Japan. Remarkable increases in the intake of meat and poultry, vegetable oils and fats, and milk and dairy products were observed in Korea from 1995 to 2005. On the other hand, these values decreased during the same period in Japan. Conclusion: The prevalence of obesity in Korea is increasing and has surpassed that of Japan. The current trends could be attributed to the low prevalence of habitual exercisers, and an increase in energy intake and the proportion of energy intake from fat.