• Korean Journal of Hydrosciences
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• 제5권
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• pp.33-43
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• 1994

This study is to determine the critical duration of design rainfall and to utilize it for the design of detention pond with pump station. To examine the effect of the duration and temporal distribytion of the design rainfall, Huff's quartile method is used for the 9 cases of durations (ranges from 20 to 240 minutes) with ten years return period, and the ILLUDAS model is used for runoff analysis. The storage ratio, which is the ratio of maximum storage amounts to total runoff volume, is introduced to determine the criticalduration of design rainfall. The duration which maximizes the storage ratio is adopted as the critical duration. This study is applied to 18 urban drainage watercheds with pump station in Seoul, of which the range of watershed area is 0.24~12.70$km^2$. The result of simulation shows that the duration which maximizes storage ratio is 30 and 60 minutes on the whole. It is also shown that the storage ratios of 2nd - and 3rd-quartile pattern are larger than those of 1st- and 4th-quartile pattern of temporal distribution. A simplified empirical formula for Seoul area is suggested by the regression analysis between the maximum storage ratio and the peak ratio. This formula can be utilized for the preliminary design and planning of detention pond with pump station.

• 한국수자원학회논문집
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• 제51권12호
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• pp.1237-1245
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• 2018

본 연구에서는 주 단위 지하수자원 관리 취약시기 평가 방법을 개발하였다. 강수의 지하수위에 대한 영향을 고려하기 위하여 한계 침투량을 고려한 강우이동평균 방법을 통해 지하수위와의 상관계수를 산정하였다. 취약 시기 평가 기준을 개발하고 평가 기준에 대한 가중치를 엔트로피 방법을 이용하여 산정하였다. 강수와의 상관계수와 산정된 가중치를 이용한 주 단위 지하수자원 관리 취약시기 평가 방법을 개발하였으며, 개발한 방법을 통하여 소규모 행정구역을 대상으로 취약시기를 평가하였다. 본 연구에서 개발된 방법은 지역적일뿐만 아니라 계절적인 지하수자원의 효율적 관리 대책 수립의 근거가 될 수 있을 것이다.

• 한국기계가공학회지
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• 제17권6호
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• pp.46-52
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• 2018

Nondestructive evaluation for mechanical degradation of ultrasuper-critical (USC) heat-resistance steel, which is attractive to the next generation of power plants is studied by magnetic reversible permeability. The interrelationship between reversible permeability and high-temperature mechanical degradation has been investigated by precise measurement of permeability nondestructively. Also, the effects of microstructural variation on reversible permeability are discussed. Isothermal aging was observed to coarsen the tempered carbides ($Cr_{23}C_6$), generated the intermetallic phases ($Fe_2W$), and grow rapidly during aging. The dislocation density also decreases steeply within lath interior. The peak to peak interval (PPI) of reversible permeability profile decreased drastically during the initial 500 h aging period, and was thereafter observed to decrease only slightly. The variation in PPI is closely related to the decrease in the number of pinning sites and the degradation in tensile strength.

• 대한건축학회논문집:구조계
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• 제36권3호
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• pp.129-134
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• 2020

The current evaluation time period for the construction management service is the project completion or after project completion. Therefore, the construction manager has the following problems. First, it is difficult to prepare the evaluation due to the new field movement of the existing participating engineer. Next, the CM work is complex as well as extensive. Therefore, the critical success factors of the construction technology services evaluation are required as a systematic performance standard of CM work. In this study, we extracted the critical success factors that can systematically prepare the evaluation from the early stage of the project through in - depth interviews with experts. And, this study was analyze the priority of each factor by using AHP technique. As a result, the most important factors were related to the systemization of the preparation process, the construction manager work capabilities and practical construction management. And the priorities of all factors were analyzed high in the factors suggested by the owner groups. The results of this analysis are expected to provide the standards that construction management service performer carry out structured management of construction management throughout the project.

• Journal of Chest Surgery
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• 제55권4호
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• pp.265-273
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• 2022

Lung transplantation is considered a viable treatment option for patients with end-stage lung disease. Recent decades have seen a gradual increase in the number of lung transplantation patients worldwide, and in South Korea, the case number has increased at least 3-fold during the last decade. Furthermore, the waiting list time is becoming longer, and more elderly patients (>65 years) are undergoing lung transplantation; that is, the patients placed on the waiting list are older and sicker than in the past. Hence, proper management during the pre-transplantation period, as well as careful selection of candidates, is a key factor for transplant success and patient survival. Although referring and transplant centers should address many issues, the main areas of focus should be the timing of referral, nutrition, pulmonary rehabilitation, critical care (including mechanical ventilation and extracorporeal membrane oxygenation), psychological support, and the management of preexisting comorbid conditions (coronary artery disease, diabetes mellitus, gastroesophageal reflux disease, osteoporosis, malignancy, viral infections, and chronic infections). In this context, the present article reviews and summarizes the pre-transplantation management strategies for adult patients listed for lung transplantation.

• International Journal of Advanced Culture Technology
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• 제11권2호
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• pp.36-43
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• 2023

This study aims to derive discourse's linguistic meaning, production method, and social practice implications by analyzing news reports on de-facility for people with disabilities. To this end, the discourse was analyzed by applying Fairclough's framework of critical discourse analysis. The subject of analysis is a news article on the de-facility of the disabled on the N portal site, and the analysis period is one year, from January 1 to December 31, 2022. First, as a result of the study, the surface meaning of the news discourse on the de-facility for disabled people was ideological through the seriousness of the problem for disabled people, the poor environment, and the policy of de-facility for disabled people separated from reality. Second, the social meaning of the de-facility news discourse for disabled people appeared from a realistic perspective, such as the structural cause of the problem for disabled people and the need for sensible government policies and measures to practice de-facility for disabled people. Finally, the socio-cultural practical implications of the de-facility news discourse for people with disabilities proposed the development of a systematic and realistic de-facility management manual for the disabled, practical government policy support, and changes in self-support perception for disabled people. The results of this study are expected to help find an alternative direction to reduce the gap between actual policies for de-facility for disabled people and practice in the field in the future.

• Journal of Trauma and Injury
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• 제36권4호
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• pp.362-368
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• 2023

Purpose: Clinical reports on treatment outcomes of sternal fractures are lacking. This study details the clinical features, treatment approaches, and outcomes related to traumatic sternal fractures over a 10-year period at a single institution. Methods: A retrospective cohort study was conducted of patients admitted to a regional trauma center between January 2012 and December 2021. Among 7,918 patients with chest injuries, 266 were diagnosed with traumatic sternal fractures. Patient data were collected, including demographics, injury mechanisms, severity, associated injuries, sternal fracture characteristics, hospital stay duration, mortality, respiratory complications, and surgical details. Surgical indications encompassed emergency cases involving intrathoracic injuries, unstable fractures, severe dislocations, flail chest, malunion, and persistent high-grade pain. Results: Of 266 patients with traumatic sternal fractures, 260 were included; 98 underwent surgical treatment for sternal fractures, while 162 were managed conservatively. Surgical indications ranged from intrathoracic organ or blood vessel injuries necessitating thoracotomy to unstable fractures with severe dislocations. Factors influencing surgical treatment included flail motion and rib fracture. The median length of intensive care unit stay was 5.4 days (interquartile range [IQR], 1.5-18.0 days) for the nonsurgery group and 8.6 days (IQR, 3.3-23.6 days) for the surgery group. The median length of hospital stay was 20.9 days (IQR, 9.3-48.3 days) for the nonsurgery group and 27.5 days (IQR, 17.0 to 58.0 days) for the surgery group. The between-group differences were not statistically significant. Surgical interventions were successful, with stable bone union and minimal complications. Flail motion in the presence of rib fracture was a crucial consideration for surgical intervention. Conclusions: Surgical treatment recommendations for sternal fractures vary based on flail chest presence, displacement degree, and rib fracture. Surgery is recommended for patients with offset-type sternal fractures with rib and segmental sternal fractures. Surgical intervention led to stable bone union and minimal complications.

• 터널과지하공간
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• 제8권1호
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• pp.53-66
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• 1998

Considering the mechanical cracking in the concrete lining of tunnels occurring in relatively short period of time after the construction, there is a need for the study on the mechanical behavior and the cracking characteristics of double lining support system(shotcrete and concrete lining). For the proposed study, downscaled lining models of Kyung-Bu High Speed Railway tunnels were tested. Most longitudinal cracks at about 93 percentage developed within 30 arch degree from the vault. Cracking load was about 30 percentage of the failure load and the deflection under the cracking load was 10 percentage of the deflection under the failure load. The overbreak around the vault contributed to the reduction of the capacity for cracking and failure by the percentage greater than the reduced effective depth. Of several rock block types considered in this research, the triangular block was the most critical, and the right triangular block under eccentric load was secondly critical for the stability of the tunnel lining system. The dimensionless support reaction curves were derived from the experimental results for single and double lining. The general equation to compute the designed flexural moment was modified.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.174-179
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• 2004

The paper deals with gravitational effect on dynamic stability of a cantilevered pipe conveying fluid. The eigenvalue branches and modes associated with flutter of cantilevered pipes conveying fluid are fully investigated. Governing equations of motion are derived by extended Hamilton's principle, and the solutions are sought by Galerkin's method. Root locus diagrams are plotted for different values of mass ratio of the pipe, and the order of branch in root locus diagrams is defined. The flutter modes of the pipe at the critical flow velocities are drawn at every one of the twelfth period. The transference of flutter-type instability from one eigenvalue branches to another is investigated thoroughly.

• 한국건축시공학회지
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• 제12권6호
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• pp.558-565
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• 2012

Schedule management of construction work is critical to completing construction projects within a given period of time. Many efforts have been made and multiple tools have been developed to support the management of construction projects using smart devices such as smartphones and tablet PCs. This study proposed a method for managing construction schedules via a smart device using Flash. The interactive and graphic properties of Flash enable the development of an app that can allow a field manager to manage schedules easily and efficiently. A prototype was implemented using Adobe Flex Builder, and a sample network was applied in a smartphone. It is convenient for a construction manager to manage construction schedules using the tool because Flash controls graphic components easily. In further studies, network diagrams such as CPM (Critical Path Method) should be developed and applied to the app.