• Smart Structures and Systems
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• 제6권4호
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• pp.363-372
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• 2010

Accurate peak response estimation of a seismically excited structure with frictional damping system (FDS) is very difficult since the structure with FDS shows nonlinear behavior dependent on the structural period, loading characteristics, and relative magnitude between the frictional force and the excitation load. Previous studies have estimated the peak response of the structure with FDS by replacing a nonlinear system with an equivalent linear one or by employing the response spectrum obtained based on nonlinear time history and statistical analysis. In case that earthquake excitation is defined probabilistically, corresponding response of the structure with FDS becomes to have probabilistic distribution. In this study, nonlinear time history analyses were performed for the structure with FDS subjected to artificial earthquake excitation generated using Kanai-Tajimi filter. An equation for the probability density function (PDF) of the displacement response is proposed by adapting the PDF of the normal distribution. Coefficients of the proposed PDF are obtained by regression of the statistical distribution of the time history responses. Finally, the correlation between the resulting PDFs and statistical response distribution is investigated.

• 대한두개안면성형외과학회지
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• 제17권4호
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• pp.218-221
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• 2016

Temporal hollowing is a common complication that occurs after coronal approach surgeries. However, temporal hollowing without previous nerve damage or trauma history is rare. Herein, we present a patient with cryptogenic temporal hollowing. A 22-year-old man without any history of craniofacial interventions or trauma presented with temporal hallowing. Magnetic resonance imaging revealed fatty degeneration of the left temporalis muscle. Electromyography and nerve conduction study showed no signs of neurologic abnormalities. The patient received autologous fat injection of 30 mL harvested from the left thigh using the modified Coleman technique. Temporal hollowing is commonly caused by atrophy of the superficial temporal fat pad. Its incidence is reported to be as high as 6% after coronal approach operation. Augmentation using porous hydroxyapatite or titanium mesh is a treatment option. Autologous fat graft can also be an option for mild to moderate temporal hollowing. In this case, a patient with no history of trauma, surgery, or myogenic disease developed temporal hollowing. Further study of the little-known cryptogenic form of temporal hollowing is warranted.

• 한국지역사회생활과학회지
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• 제15권2호
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• pp.159-166
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• 2004

This study was undertaken to investigate the severity of depression and to analyze various factors related to depression in chronic back pain patients in urban-rural areas. In this study, 30 patients who suffered from back pain more than 6 months, and 30 normal subjects who had similar demographic characteristics as the patient group were evaluated using the Back Depression Inventory(BDI). Various factors such as age, sex, causes of back pain, vocational history, pain continuity, visual analogue scale(VAS), duration of pain, type of management, and urban or rural residence were recorded for the study group. The results are 1) The study group revealed higher BDI scores than the control group(p＜0.05). 2) The patients who were older and had higher VAS, longer duration of pain, or previous history of surgical management for back pain, and an urban 033residence revealed higher BDI scores(p<0.05). 3) The BDI scores were not significantly influenced by the subjects' sex, causes of back pain, pain continuity, and vocational history in the study group(p>0.05). From this study, we concluded that a Psychosocial approach is required for the management of chronic back pain patients. Also, it is necessary to assess the factors, which are making depression worse in other chronic diseases for comprehensive rehabilitation.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.639-644
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• 2007

The accurate peak response estimation of a seismically excited structure with frictional damping system(FDS) is very difficult since the structure with FDS shows nonlinear behavior dependent on the structural period, loading characteristics, and relative magnitude between the frictional force and the excitation load. Previous studies have estimated that by replacing a nonlinear system with an equivalent linear one or by employing the response spectrum obtained based on nonlinear time history and statistical analysis. In the case that on earthquake load is defined with probabilistic characteristics, the corresponding response of the structure with FDS has probabilistic distribution. In this study, nonlinear time history analyses were performed for the structure with FDS subjected to artificial earthquake loads generated using Kanai-Tajimi filter. An equation for the probability density function (PDF) of the displacement response is proposed by adapting the PDF of the normal distribution. Finally, coefficients of the proposed PDF is obtained by regression analysis of the statistical distribution of the time history responses. Finally, the correlation between PDFs and statistical response distribution is presented.

• 한국식생활문화학회지
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• 제34권2호
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• pp.93-111
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• 2019

This paper provides a comprehensive description of previous studies of making and developing kimchi in terms of the origins of kimchi and the changes in the history of kimchi, along with newly discovered data, including the collection of works in Joseon Dynasty as well as old cookbooks discovered after the year 2000, and latest research in related disciplines, e.g., ancient history studies, archeology, and linguistics. Because new ruins and relics, such as the Liao-ho Civilization in the Northeast Asia continent, which was closely related to Dongyi tribes, have been discovered and studied, it is important to determine how to reflect the outcome of archeological studies on the origin of preserved vegetables. In addition, to describe the background and changes in the independent formation of making Korean kimchi chronologically, they were divided into the following: development from jjanji to singunji; formation of the basis for seokbakji dressed with fermented fish sauce; settlement of seokbakji culture for dressing seokbakji with fermented fish sauce and spices, including chili varieties when they were introduced; and establishment of the method for making whole cabbage kimchi, which is currently typical kimchi made by adding the seokbakji as the stuffing of the cabbage kimchi, to examine the time and specific details of the change.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권2호
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• pp.79-84
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• 2022

Objectives: The purpose of this study was to evaluate risk factors and symptoms in cemento-osseous dysplasia (COD) patients. Materials and Methods: In this study, 62 patients who were diagnosed histologically with COD were investigated from 2010 to 2020 at the author's institution. We compared clinical and radiological characteristics of symptomatic and asymptomatic patients. The factors were sex, age, lesion size, site, radiologic stage of lesion, apical involvement, sign of infection, and history of tooth extraction. Statistical analysis was performed using Fisher's exact test and the chi-square test. Results: COD was more prevalent in female patients. With the exception of three cases, all were focal COD. The majority of patients presented with symptoms when the lesion was smaller than 1.5 cm in size. Symptoms were observed when the apex of the tooth was included in the lesion or there was a local infection around the lesion. The history of tooth extraction and previous endodontic treatment were evaluated, and history was not a significant predictor for the onset of symptoms. Conclusion: In this study, risk factors associated with symptomatic patients were size of lesion, apical involvement, and local infection.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1336-1342
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• 2022

Risk-informed safety classification of structures, systems and components (SSCs) is very important for ensuring the safety and economic efficiency of nuclear power plants (NPPs). However, previous methods for safety classification of SSCs do not take the plant operating modes or the operational process of SSCs into consideration, thus cannot concentrate on the safety and economic efficiency accurately. In this contribution, a new method for safety classification of SSCs based on the categorization of plant operating modes is proposed, which considers the NPPs operating history to improve the economic efficiencies while maintaining the safety. According to the time duration of plant configurations in plant operating modes, average importances of SSCs are accessed for an NPP considering the operational process, and then safety classification of SSCs is performed for plant operating modes. The correctness and effectiveness of the proposed method is demonstrated by application in an NPP's safety classification of SSCs.

• 한국수학사학회지
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• 제21권2호
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• pp.1-18
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• 2008

이 논문은 18세기 조선의 구고술에 이어서 19세기 조선의 구고술의 발달을 연구하여 조선 산학의 발전을 규명한다. 홍길주(洪吉周), 남병길(南秉吉), 이상혁(李尙爀), 조희순(趙羲純)등의 구고술의 사료 분석을 통하여 19세기 조선의 구고술의 특성을 연구한다.

• 건축역사연구
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• 제23권4호
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• pp.81-90
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• 2014

This paper aimed to identify the variation of layout in Hwangnyoungsa buddhist temple site based on studying published the excavation research paper and texts related to layout. According to earlier studies, in 1st construction period(553~569) of Hwangnyoungsa, there were trisection spaces with one main hall and two corridors in inner part and then in 2nd period(584~645), unified one. But actually trisection spaces had been maintained until the middle part of 8th century. And in each space there was the main hall with large yard. That is the 2nd period layout of Hwangnyoungsa. For the attainment this result, each building remains are judged under duplicated situation which one was the previous and next by consideration of the construction condition and special features of foundation. Although the meaning of trisection system of Hwangnyoungsa is similar with the layout of ancient palace, it could be said to derive from accumulation excavation research in Silla's archeological site and such studies.

• 건축역사연구
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• 제25권5호
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• pp.15-25
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• 2016

The color that painted on the ground of Dancheong becomes Gachil(basecoat)-Dancheong and underpainting of Moro-Dancheong or Geum-Dancheong. So, the color of underpainting is the most important element that determines impression of the building. Thus, the architecture after using "Sangrokhadan" has different characters from what it had been. In the existing perception toward the background color of Dancheong, it was considered the characters of Korean Dancheong so-called "Sangrokhadan" that paint vertical elements like columns red and upper part of the columns green. But this study examined the color of Dancheong according to the era and region before and after Goryeo Dynasty era, then it reveals that Sangrokhadan technique was applied from the 14th century in the late Goryeo Dynasty. One of the Goryeo architecture, Geungnakjeon Hall of Bongjeongsa Temple is thought to be a previous style that is not applied "Sangrokhadan" technique because old elements are painted red pigment.