• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.35-50
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• 2022

After the introduction of the central bus lane system, bus traffic was prioritized. This resulted in improved trust from bus users. However, the low capacity at the central bus stop reduces traffic speed and punctuality. In addition, physical constraints are inevitable because the construction of central bus lanes and bus stops considers the city's road geometry. Therefore, this study attempted to optimize the effective green time of the traffic signal system at the entrance and exit of the central bus stop to remedy its insufficient operational capacity. The Transit Capacity and Quality of Service Manual and Korea Highway Capacity Manual were used as the analysis methodologies. The number of stop areas for central bus stops to be built was determined by excluding variable physical factors, and field survey data collected from nine randomly selected central bus stops currently installed in Seoul were used. A scenario analysis was conducted on the central bus stops with insufficient capacity by adjusting the effective green time, and the capacity of the central bus stop was set as the dependent variable. According to the results, 26.7 percent of the central bus stops with insufficient capacity can solve the problem of insufficient capacity. Therefore, the results of this study can be verified by improving the operation level, and it can be effective even if the number of central bus stops calculated by engineering is not guaranteed during the planning stage of the central bus stop. As the number of central bus stops is expected to increase further as the number of central bus stops increases, it is necessary to improve the number of central bus stops. Therefore, it is hoped that the results presented in this study will be used as basic data for the improvement plan at the operational level before introducing the physical improvement plan.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4C
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• pp.247-254
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• 2006

Online testing method is one of the numerical experiment methods using experimental information for a numerical analysis directly. The method has an advantage in that analysis can be conducted without using an idealized mechanical model, because mechanical properties are updated from element test for a numerical analysis in real time. The online testing method has mainly been used for the geotechnical seismic engineering, whose major target is sand. A testing method that may be applied to a consolidation problem has recently been developed and laboratory and field verifications have been tried. Although related research thus far has mainly used a method to update average reaction for a numerical analysis by positioning an element tests at the center of a consolidation layer, a weakness that accuracy of the analysis can be impaired as the thickness of the consolidation layer becomes more thicker has been pointed out regarding the method. To clarify the effectiveness and possible analysis scope of the online testing method in relation to the consolidation problem, we need to review the results by applying experiment conditions that may completely exclude such a factor. This research reviewed the results of the online consolidation test in terms of reproduction of the consolidation settlement and the dissipation of excess pore water pressure of a clay specimen by comparing the results of an online consolidation test and a separated-type consolidation test carried out under the same conditions. As a result, the online consolidation test reproduced the change of compressibility according effective stress of clay without a huge contradiction. In terms of the dissipation rate of excess pore water pressure, however, the online consolidation test was a little faster. In conclusion, experiment procedure needs to improve in a direction that hydraulic conductivity can be updated in real time so as to more precisely predict the dissipation of excess pore water pressure. Further research or improvement should be carried out with regard to the consolidation settlement after the end of the dissipation of excess pore water pressure.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.3
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• pp.153-165
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• 2023

The purpose of this study is to propose effective scenarios for green areas in apartment complexes that can improve the connection between green spaces considering wind flow, thermal comfort, and mitigation of the urban heat island effect. The study site was an apartment complex in Godeok-dong, Gangdong-gu, Seoul, Korea. The site selection was based on comparing temperatures and discomfort index data collected from June to August 2020. Initially, the thermal and wind environment of the current site was analyzed. Based on the findings, three scenarios were proposed, taking into account both green patches and corridor elements: Scenario 1 (green patch), Scenario 2 (green corridor), and Scenario 3 (green patch & corridor). Subsequently, each scenario's wind speed, wind flow, and thermal comfort were analyzed using ENVI-met to compare their effectiveness in mitigating the urban heat island effect. The study results demonstrated that green patches contributed to increased wind speed and improved wind flow, leading to a reduction of 31..20% in the predicted mean vote (PMV) and 68.59% in the predicted percentage of dissatisfied (PET). On the other hand, green corridors facilitated the connection of wind paths and further increased wind speed compared to green patches. They proved to be more effective than green patches in mitigating the urban heat island, resulting in a reduction of 92.47% in PMV and 90.14% in PET. The combination of green patches and green corridors demonstrated the greatest increase in wind speed and strong connectivity within the apartment complex, resulting in a reduction of 95.75% in PMV and 95.35% in PET. However, patches in narrow areas were found to be more effective in improving thermal comfort than green corridors. Therefore, to effectively mitigate the urban heat island effect, enhancing green areas by incorporating green corridors in conjunction with green patches is recommended. This study can serve as fundamental data for planning green areas to mitigate future urban heat island effects in apartment complexes. Additionally, it can be considered a method to improve urban resilience in response to the challenges posed by the urban heat island effect.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.57-70
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• 2009

Considerable advance has been made on research on effect of steel pipe Umbrella Arch Method (UAM) and mechanical reinforcement mechanism through numerical analyses and experiments. Due to long analysis time of three-dimensional analysis and its complexity, un-quantitative two-dimensional analysis is dominantly used in the design and application, where equivalent material properties of UAM reinforced area and ground are used, For this reason, development of reasonable, theoretical, quantitative and easy to use design and analysis method is required. In this study, both field UAM tests and laboratory tests were performed in the residual soil to highly weathered rock; field tests to observe the range of reinforcement, and laboratory tests to investigate the change of material properties between prior to and after UAM reinforcement. It has been observed that the increase in material property of neighboring ground is negligible, and that only stiffness of steel pipe and cement column formed inside the steel pipe and the gap between steel pipe and borehole contributes to ground reinforcement. Based on these results and concept of Convergence Confinement Method (CCM), two dimensional axisymmetric analyses have been performed to obtain the longitudinal displacement profile (LDP) corresponding to arching effect of tunnel face, UAM effect and effect of supports. In addition, modified load distribution method in two dimensional plane-strain analysis has been suggested, in which effect of UAM is transformed to internal pressure and modified load distribution ratios are suggested. Comparison between the modified method and conventional method shows that larger displacement occur in the conventional method than that in the modified method although it may be different depending on ground condition, depth and size of tunnel, types of steel pipe and initial stress state. Consequently, it can be concluded that the effect of UAM as a beam in a longitudinal direction is not considered properly in the conventional method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.557-564
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• 2009

In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast overpressure is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, information and test results related to the blast experiment of internal and external have been limited due to military and national security reasons. Therefore, in this paper, to evaluate blast effect on reinforced have concrete structure and its protective performance, blast tests are carried out with $1.0m{\times}1.0m{\times}150mm$ reinforce concrete slab structure at the Agency for Defence Development. The standoff blast distance is 1.5 m and the preliminary tests consists with TNT 9 lbs and TNT 35 lbs and the main tests used ANFO 35 lbs. It is the first ever blast experiment for nonmilitary purposes domestically. In this paper, based on the basic experiment procedure and measurement details for acquiring structural behavior data, the blast experimental measurement system and procedure are established details. The procedure of blast experiments are based on the established measurement system which consists of sensor, signal conditioner, DAQ system, software. It can be used as basic research references for related research areas, which include protective design and effective behavior measurements of structure under blast loading.

• Korean Journal of Psychosomatic Medicine
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• v.31 no.1
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• pp.10-18
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• 2023

Objectives : The purpose of this study is to investigate the characteristics of patients referred for delirium and depressive disorder and to find direction of improvement of consultation-liason psychiatry in general hospital. Methods : We performed a retrospective computed chart review of the 4,966 inpatients hospitalized at Konkuk University Hospital who were referred to the Department of Psychiatry from August 1, 2005 to December 31, 2011. Results : Depressive disorder shows the order of frequency of consultation type Parallel-Complementary-Mending. Delirium shows the order of frequency of consultation type Mending-Parallel-Complementary. When comparing 'follow up consultation' and 'without follow up consultation' group within the depressive disorder, the proportion of men in the 'follow up consultation' group was higher. In the analysis of the consultation type, the 'follow up consultation' group showed the order of consultation type Parallel-Mending- Complementary, and type Parallel-Complementary-Mending in the 'without follow up consultation' group. When comparing 'follow up consultation' and 'without follow up consultation' group within the delirium, the proportion of the surgical field in the 'follow up consultation' group was higher. In the analysis of the consultation type, both group showed the order of consultation type Mending-Parallel- Complementary. Conclusions : Doctors in each department and psychiatrists should pay attention to delirium symptoms that may occur in surgical inpatients and preventive measures should be taken. Screening tests should be conducted in medical patients to properly evaluate coexisting psychiatric diseases. Risk factors of Delirium and Depressive disorder should be identified from the time of hospitalization, and actively discussing treatment plans and early interventions could improve the quality of medical services.

• Exercise Science
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• v.23 no.1
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• pp.1-11
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• 2014

The purpose of this study was to develop and validate regression models to estimate maximal oxygen uptake (VO₂max) from the 20 m Progressive Shuttle Run Test (20 m PSRT) in Korean middle-school girls aged 13-15 years. The 20 m PSRT and VO₂max were assessed in a sample of 194 participants. The sample was randomly split into validation (n=127) and test-retest reliability (n=99, 32 out of 127 participants also performed validity test) groups. 127 participants performed a graded exercise test (GXT, stationary gas analyser) and the 20 m PSRT (portable gas analyser) once to develop a VO₂max prediction model and to analyze the validity of the modified 20 m PSRT protocol (starting at 7.5 km/h and increasing by 0.5 km/h every 1 min). 99 participants performed the 20 m PSRT twice for test-retest reliability purpose. Mean measured VO₂max (39.2±5.1 ml/kg/min) from the potable gas analyzer was significantly increased from that measured during the GXT from stationary gas analyzer (37.7±5.7 ml/kg/min, p=.001) using the modified 20 m PSRT protocol. But it was a narrow range (1.5 ml/kg/min). The measured VO₂max from the potable and stationary gas analyzers correlated at r=.88(p<.001). Test-retest of the 20 m PSRT yielded comparable results (Laps r=.88 & final speed r=.85). New regression equations were developed from present data to predict VO₂max for middle-school girls: y=.231×Laps-.311×weight(in kg)+46.201 (r=.74, SEE=4.29 ml/kg/min). It is concluded that (a) the modified 20 m PSRT protocol is a valid and reliable test and (b) this equation developed in this study provides valid estimates of VO₂max of Korean middle-school girl aged 13-15 years.

• 한국노년학
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• v.29 no.2
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• pp.629-643
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• 2009

The purpose of this study is, by using the demographic variables, to identify self-efficacy, social support, and quality of life of the elderly with depression and to assess the impacts of these factors upon their quality of life. By analyzing the factors which have an impact upon the life quality of the elderly with depression, this study aims to provide important information which help understand them, and to find out what kind of care is necessary for their happy and satisfactory life. The study took purposive sampling and survey of 215 people among the elderly with depression who were under care of the outpatient clinics, day hospitals, and mental health clinics located in Seoul and Kyunggi Province, Korea. This study was conducted from November 10th to 20th, 2008 and the data were collected using the questionnaires of self-efficacy, social support, and quality of life scales. Using a SPSS/WIN 15.0 program, the analysis of the data showed the following results. First, among the demographic characteristics, the elderly with depression who were male, had spouse, higher education, no public assistance, shorter period of depression, and were healthy turned out to have higher self-efficacy. In terms of social support, the participants who had higher education, no public assistance, and were healthy turned out to have more social support. Further, in terms of quality of life, the variables of spouse, public assistance, period of depression, and health condition were statistically significant. Second, as a result of hierarchical regression, it appeared that the elderly with depression, who had higher self-efficacy, more social support, spouse, good health, no public assistance, and shorter period of depression, turned out to have higher quality of life. Based on the study findings, the implications of social work practice, policy, and future research were discussed.

• 한국노년학
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• v.31 no.3
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• pp.505-526
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• 2011

The purposes of this paper were to examine the level of knowledge of and attitudes toward the elderly and investigate the differences in the level of knowledge of and attitudes about the elderly by selected socio-demographic factors and aging related factors in Korea and the United States. The research subjects were 1129 college students attending 10 schools in Korea and the United States(840 Korean students in 5 schools, located in Seoul City, Gyeonggi-Do, Chungcheong-Do in Korea and 289 American students in 5 schools located in the State of New York of the United States). They were interviewed, using the structured questionnaire, and the data were analyzed by SPSS 15.0 for Windows. The research questionnaire was composed of Fact on Aging Quiz Part 1(FAQ 1) developed by Palmore(1998), Semantic Differential Scale development by Sanders et al., and several socio-demographic and aging related variables. The results indicated that, first, the level of knowledge of the elderly for Korean students was 12.51/25 and for American students was 11.57/25, resulting that the knowledge level of the elderly in Korea was higher than that of the United States. In addition, the results of students' knowledge differences between korea and the United States showed that Korean students showed high ratio of correct answer in 9 questions while American students showed high ratio of correct answer in only 4 questions, resulting that Korean students have higher knowledge than American students. Second, the level of attitudes toward the elderly for Korean students was 77.54 and for American students was 70.07 in 20-140 points, resulting that the attitude level of the elderly among American students were more positive than that of Korean students. The results of students' attitudes differences between Korea and the United States showed that Korean students responded positive tendency in only one question while American students responded positive tendencies in 14 questions, resulting that American students were more positive attitudes toward the elderly than that of Korean students. Third, there is a significant correlation between the knowledge of and attitudes toward the elderly in both Korean and American students. Based on these results, implications for policy, practice, and research were further discussed.

• 한국노년학
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• v.30 no.4
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• pp.1359-1375
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• 2010

Expecting the expansion of the elderly population under long-term home care with the coming of the aged society, this study purposed to propose a prevention and self-reliance support model and to get practical implications for minimizing dependency on care benefits and enhancing the effectiveness of prevention and self-reliance support. Research methods employed for this study were: first, reviewing theoretical literature for clarifying the concept of prevention and self-reliance support in providing long-term care benefits for the elderly; second, identifying factors hindering prevention and self-reliance support through analyzing standard long-term care use plans and documents related to long-term care benefits at elderly welfare centers to which the research subjects belonged; and third, surveying care benefit users on factors hindering their use of prevention and self-reliance support and their needs in the use of care benefits. Based on the results of the three types of qualitative research, we proposed directions for prevention and self-reliance support modeling and suggested practical implications for enhancing the effectiveness of prevention and self-reliance support. For this study, we collected documentary materials and conducted in-depth interviews with the participants with the consents and cooperation of managers and professional social workers at day care centers and elderly welfare centers in D City. According to the results of this study, literature review suggested that long-term care prevention and self-reliance support should be provided in a way of 'strengthening user-centered support systems,' which support elderly long-term care beneficiaries' right to lead a life as the subject of their own life. Document analysis found the absence of benefits related to health and medicine and lack of social support systems for prevention and self-reliance support, and the results of in-depth interviews suggested the necessity to strengthen services related to elderly long-term care beneficiaries' prevention and self-reliance, and the keen needs of the long-term care elders for prevention and self-reliance included: ① loneliness, anxiety, fear; ② missing for and worry about children and people; ③ moving, outing; ④ health and medical services, rehabilitation programs; ⑤ desire to use day care; ⑥ inconvenience of house structure; ⑦desire for meal menus; and ⑧ the occurrence of disuse syndrome. Based on these results, we suggested the base of prevention and self-reliance support modeling with three axes: ① strengthening user-centered support systems; ② strengthening support systems connected to health and medicine; and ③ strengthening social support systems.