• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.178-185
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• 1999

Minimum life-cycle cost helps to evaluate cost effectiveness of base-isolated bridges under specific condition. Life-cycle cost mainly consists of the initial construction cost and the expected damage cost. Damage cost estimation needs proper model of input ground motion failure probability evaluation method and limit states definition. We model the input ground motion as spectral density function compatible with the response spectra defined at each seismicity and site condition. Spectrum analysis and crossing theory is suitable for reseating calculation of failure probabilities in the process of cost minimization. Limit states of base-isolated bridges re defined for superstructure isolator and pier respectively The method is applied to both base-isolated bridges and conventional bridges under the same conditions to investigate cost effectiveness of base isolation in low and moderate seismic region. the results show that base-isolation of bridges are more effective in low and moderate seismic region and that the site effects on the economical efficiency may not be negligible in such a region.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.219-220
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• 2019

교내 기자재가 고장이 나면 사용자는 수리하는 담당자에게 직접 연락을 하여 조취를 취한다. 고장수리 담당자의 처리 여부에 대한 확인은 유선으로 상호간에 확인하는 방법뿐이다. 본 연구를 통해 고장 난 기자재를 처리하고 싶은 사용자를 위해 실시간으로 처리 현황을 확인 할 수 있는 인터페이스와 기능을 지원하는 시스템을 개발하였다. 관리자는 해당 분류에 맞게 처리하는 담당자를 구별해 시스템에 글을 게시하고, 담당자는 담당 부서 게시물만 열람할 수 있도록 하여 빠른 일처리를 지원할 수있는 기능을 중점으로 개발하였다. 또한 하나의 기자재마다 책임자를 구별하고 처리 완료된 기자재의 종류의 기록과 통계를 사용자와 담당자가 보기 어려운 단위나 수치보다는 시각적인 효과를 받기 위한 그래프의 사용과 색상을 통하여 알림을 전해준다.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.133-141
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• 1993

From Jan.1982 to Dec.1990, 77 patients with rectal cancer were treated with curative surgical resection followed by postoperative adjuvant irradiation alone or combined with chemotherapy at the Department of Radiation Oncology, Korea University Hospital (KUH). Fifty-four (54/77, $70.1{\%}$) patients underwent abdominoperineal resection , 20 (20/77, $26{\%}$) patients underwent low anterior resection, and 3 (3/77, $3.9{\%}$,) patients had wide excision only. Thirty-nine (39/77, $50.5{\%}$) received sequential chemotherapy (2 cycles to 12 cycles). The 5-year survival rate for the entire group was $43{\%}:\;78.2{\%}$ in B2+B3, $39.4{\%}$ in stage C1+C2+C3. Survival rates decreased with increasing penetration of the bowel wall by tumor and the presence of regional lymph node metastasis. Those patients survival who underwent an abdominoperineal resection also experienced a significant decrease in compared to low anterior resection ($23.1{\%}$ vs. $63.8{\%}$ in 5-year survival, p <0.05). Local failure occurred in 15 ($19.5{\%}$) out of the 77 patients overall, 1($5.3{\%}$) of 19 in stage B2+B3, and 14 ($24.1{\%}$,) of 58 in stage C1+C2+C3. Presacral area was most common site of local failufre (8/17, $47.1{\%}$). Distant failure occurred in 13 ($16.9{\%}$) of 77 patients. The most frequent site of distant failure was the lung followed by the liver, the bone, and the brain. Combined locoregional and distant failure occurred in 2 ($2.6{\%}$) of 77 patients. Pathological confirmation of perirectal fat and/or regional lymph node involvement resulted in a singificant decrease in survival and local control.

• Journal of the Korean Society of Safety
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• v.35 no.6
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• pp.1-8
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• 2020

In recent years, hydrogen has received much attention as an alternative energy source to fossil fuels. In order to ensure safety from the increasing number of hydrogen refueling stations, prevention methods have been required. In this regard, this study suggested an approach to reduce the risk of hydrogen refueling station by increasing Safety Integrity Level (SIL) for a Steam Methane Reformer (SMR) in On-Site Hydrogen Refueling Station. The worst scenario in the SMR was selected by HAZOP and the required SIL for the worst scenario was identified by LOPA. To verify the required SIL, the PFDavg.(1/RRF) of Safety Instrumented System (SIS) in SMR was calculated by using realistic failure rate data of SIS. Next, several conditions were tested by varying the sensor redundancy and proof test interval reduction and their effects on risk reduction factor were investigated. Consequently, an improved condition, which were the redundancy of two-out-of-three and the proof test interval of twelve months, achieved the tolerable risk resulting in the magnitude of risk reduction factor ten times greater than that of the baseline condition.

• Tunnel and Underground Space
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• v.16 no.6 s.65
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• pp.506-525
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• 2006

For the design of large scale rock slope which has complex formations and geological structures, generally, insufficiency of geotechnical investigations and laboratory tests are the main factors of slope failures doling construction. In such case, remedial measures to stabilize slope should be selected and applied through reliable investigations and analysis considering the geotechnical characteristics. The rock slope of this study, one of the largest cut slopes in Korea with a length of 520.0 m and maximum height of 122.0 m consists of metasedimentary rocks. And a case study on the causes of large-scale rock slope failure was carried out by analysis of landslides history and site investigations during construction. When the slope with the original design slope of 0.7: 1.0 (H:V) was partially constructed, the slope failure was occurred due to the factors such as poor conditions of rocks (weathered zone, coaly shale and fault shear zone), various discontinuities (joints, foliations and faults), severe rain storm and so on. The types of failures were rockfall, circular failure, wedge failure and the combination of these types. So, the design of slope was changed three times to ensure long-term slope stability. This paper is intended to be a useful reference for analyzing and estimating the stability of rock slopes whose site conditions are similar to those of this study site such as geological structures and geotechnical properties.

• 한국전자현미경학회:학술대회논문집
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• 2001.11a
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• pp.70-74
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• 2001

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.139-142
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• 2003

As composite materials are gaining wide acceptance in aircraft structure, repair of damaged composite is becoming an important issue. The issues in composite repair include high cost, material interchangeability, water ingression, and structural integrity. To address these problems, researchers have studied on the composite repair in various aspects. In this paper, an Internet-based advisory service (called Repair Advisory Service, RAS) for composite repair is proposed to increase efficiency for repair process. In the RAS system the web browser is used as its user interface, which provides easy access to the service. The RAS server provides web-based tools for failure prediction, Structural Repair Manual (SRM), automated prepreg cutting process, material properties, inventory and knowledge base. The computer codes implemented for repair design estimate the tensile failure and shear failure of repaired structures. The prediction of failure is based on the maximum strain criterion for tensile failure while elastic-perfect plastic shear failure model is applied for interfacial failure. The OEM's SRM is provided in the PDF format for viewing and searching by web browsers instead of looking up paper version SRM. The knowledge base in this site offers a room to share and distribute ideas, memos, publications, or suggestions from the repair engineers. The fabrication tool of RAS reads repair geometry from engineers then generates a CNC toolpath to cut prepreg patches. The RAS service is open to public and available at http://nano.gsnu.ac.kr/. Broad feedback from field technicians and engineers is welcome to improve the usefulness of RAS.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.117-122
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• 2003

Every year in domestic slope failure caused by rainfall is happening frequently. Specially, causable failure accident by localized downpour accompanied when summer rainy season period and produces typhoon gets damage of large scale human life and property. Failure happened at slope of 121 places ranged whole country national highway by No.15 typhoon Rusa that strike whole country during 3 days from August 30, 2002. Slope failure that happen by typhoon are judged for major cause to effect of ground saturation and surface water by localized downpour. In this research, failure characteristic was analyzed to target 20 places attaining site investigation among failure slope. As a result, erosions by surface water was construed for major cause of failure and judged for direct relation in failure slope weathering and topography Also, result that analyze inclination of failure part, in the case of ripping rock, inclination of failure side is forming Incline of the lowest 40$^{\circ}$, because surface failure of depth 4m on or so scale happened, it is require that regulating plan gently design standard inclination of weathered rock and soil layer And it is considered that desirable preparation of design standard about measure that help smooth drainage of surface water and can restrain percolation in ground to reduce failure damage by rainfall.

• Radiation Oncology Journal
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• v.2 no.2
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• pp.191-202
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• 1984

Biological behavior and treatment results of 33 patients with Adenoid Cystic Carcinoma (ACC) in the Head and Neck at Yonsei Cancer Confer for 10 years between 1971 and 1980 were retrospectively analysed. Most common, primary site was minor salivary glands such as maxillary sinus, nasal cavity and base of tongue. The typical biological behavior of these tumors was very slowly in growth with long time of duration(mean 19 months) from 1 month to 10 years and more frequent of nerve invasion but rare invasion of neck nodes. Local control and failure pattern in the results of treatment, 16 of 17 patients with irradiation alone were seen complete or partial response but 5 cases of locoregional recurrence, 2 cases of failure of neck node and 4 cases of distant metastasis as lung and brain. On the other hand, among 10 cases of surgery and postoperative irradiation, 2 cases of locoregional failure and 3 cases of distant metastasis as lung and bone. 2 of 4 cases with surgery alone were recurred within primary site. Actuarial overall NED survival at 3 ana 10 years were $52.6\%$ and $42.8\%$, respectively. Survival rate of 10 Patients with surgery and Postoperative irradiation was more high than 17 Patients of radiation alone. Therefore, we have known that surgery with postoperative adjunctive irradiation is most effective treatment modality of adenoid cystic carcinoma in the head and neck. Primary site, treatment modality and with or without nerve ana bone invasion have influenced on prognosis.

• International Journal of Contents
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• v.8 no.3
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• pp.71-78
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• 2012

The emergence of the Internet has provided a new outlet for consumers who experience service failure from products and services, augmenting the traditional options of entry, voice and action. Consumers' negative word of mouth through online (word-of-mouse or eWOM) far exceeds traditional word of mouth (WOM) in respect of its potential effectiveness, speed and spread. This paper tries to figure out the service failure themes in the health care industry by analyzing online word-of-mouse using the critical incidents technique (CIT). Complaint themes in the area of healthcare are identified and analyzed. The results identify that major complaint theme differed according to the site type. Also, the findings indicate that delivery and customer services are critical issues when consumer makes negative WOM.