• 보건행정학회지
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• 제26권1호
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• pp.71-78
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• 2016

The value of using health insurance claim database is continuously rising in healthcare research. In studies where comorbidities act as a confounder, comorbidity adjustment holds importance. Yet researchers are faced with a myriad of options without sufficient information on how to appropriately adjust comorbidity. The purpose of this study is to assist in selecting an appropriate index, look back period, and data range for comorbidity adjustment. No consensus has been formed regarding the appropriate index, look back period and data range in comorbidity adjustment. This study recommends the Charlson comorbidity index be selected when predicting the outcome such as mortality, and the Elixhauser's comorbidity measures be selected when analyzing the relations between various comorbidities and outcomes. A longer look back period and inclusion of all diagnoses of both inpatient and outpatient data led to increased prevalence of comorbidities, but contributed little to model performance. Limited data range, such as the inclusion of primary diagnoses only, may complement limitations of the health insurance claim database, but could miss important comorbidities. This study suggests that all diagnoses of both inpatients and outpatients data, excluding rule-out diagnosis, be observed for at least 1 year look back period prior to the index date. The comorbidity index, look back period, and data range must be considered for comorbidity adjustment. To provide better guidance to researchers, follow-up studies should be conducted using the three factors based on specific diseases and surgeries.

• 한국가구학회지
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• 제12권1호
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• pp.91-101
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• 2001

This study explored the trend of postwar period American furniture design and analyzes the contexts of the trend. To be more specific, this study categorized the types of the styles or "looks" of furniture which were dominant in postwar period America: the machine look ; the handicraft look ; the biomorphic look. The background and the context for each look were traced back and analyzed both diachronically and synchronically. Based on the analysis, this study provided two conclusions. First, postwar period American furniture design is in many ways indebted to the World War II, because the war itself and postwar economic revival produced high demands for furniture, which consequently produced a variety of looks of furniture. Second, the furniture design in this period is attributed to commercialism and consumer-oriented design policy formulated in the mid 1920′s when American design established its own identity separating from European avant-gardism.

• 복식
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• 제50권3호
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• pp.117-131
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• 2000

The purpose of this study is for affirmation about fashion and film industry has very important relationship through the image of film fashion in 1990. To this processing , films in 1990 were analyzed by the back ground, time place, persons's status are expressed in period movie but the person's characters, development of story mood in contemporary movies. The contents of this study are as follows : First, film fashion which was related mass fashion design and concept development and fashion designers as constume services were considered. Second, the change of star image through the 20th century. The roles and new image of film fashion in period movies and contemporary movies in 1990 were searched. Third, proposal and results were confirmed for expansion of fashion industry and film industry together. Finally, from the latter of 20th century, a lot of fashion designers have participated in film works than before, So the images of films were sued and reflected as new mass trend . Especially retro-romantic mood was expressed in fashion trend due to period movie fashion. Also minimal city look and elegance glamourous look are represented cause of contemporary movie fashion. Therefore, the cooperation between film productions and fashion professionals is very important for promotion of Korean culture development in 21st century, 'the century of image'.

• 전자공학회논문지SC
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• 제44권5호
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• pp.62-70
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• 2007

본 논문에서는 일정 토크영역에서 승압형 PFC 컨버터와 직접토크제어(DTC) 방법을 사용하여 BLDC 모터의 구동 시스템을 DSP(TMS320F2812)로 구현하였다. 기존의 6단계 PWM 전류제어와 달리 미리 정한 샘플시간 마다 간단한 look-up 표로부터 2상 도통 모드에 대한 인버터의 전압 상태 벡터를 설정함으로써 원하는 전류파형을 만들었으며 이로부터 기존의 전류제어기보다 훨씬 빠른 토크 응답특성을 얻을 수 있었다. 또한 BLDC 모터의 비 이상적인 사다리형 역기전력에 의해 발생되는 저주파 토크변동을 저감하기 위하여 위치 loop-up 표를 사용하였다. 아울러 역률을 보정하기 위해 승압형 PFC 컨버터를 구성하였고 이 때 전파 정류된 입력전압과 출력전압, 인덕터의 전류에 의해 평균전류모드 제어 방식으로 80 kHz마다 PWM 듀티(duty)가 조절 되도록 하였다. 이와 같이 복잡한 제어 알고리즘은 초고속 DSP의 출현으로 PFC와 DTC 알고리즘이 동시에 제어가 가능하며, 본 논문에서는 DTC 알고리즘을 구현할 때 DSP의 일반 범용의 출력포트를 사용하여 구현하였고 단지 PFC에서만 1개의 PWM을 사용하여 디지털 제어기를 구현하였다. 실험을 통해 DTC 알고리즘과 PFC 컨버터를 이용한 BLDC 모터 구동 시스템의 타당성과 효용성을 보였고, 실험결과로부터 PFC 컨버터를 사용하지 않았을 때는 역률이 약 0.77이었으나 PFC 컨버터를 사용하였을 때는 부하변동에 관계없이 약 0.9997로 크게 향상됨을 확인하였다.

• Journal of Astronomy and Space Sciences
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• 제24권4호
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• pp.261-268
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• 2007

We have studied the temporal variation in the North-South asymmetry of the sunspot area during the period from 1874 to 2007. Though the 9-year periodicity is commonly reported, shorter periodicities is still under study. We employ the cepstrum analysis method to analyze the noisy power spectrum of the North-South asymmetry. We demonstrate that the cleaned power spectrum shows reduction of the spurious back-ground noise level. Some of short period peaks in the power spectrum disappear after deconvolution. It should be, however, pointed out that power spectrum might look less noisy because of a filtering process during deconvolution. We conclude by pointing out that a more sophisticate filtering algorithm is required to produce a precise and reliable periodicity estimate.

• 한국수학사학회지
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• 제17권1호
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• pp.69-86
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• 2004

Discussing the history of mathematics in classrooms is often recommended as a way to help show that mathematics was not handed down unchanged from God into the students' notebooks but has been changing and growing throughout the centuries. Now that new millenium century is begun, it is appropriate for historians to look back and for teachers to show that mathematics is not only alive and well but in its most productive period ever. This paper is a brief summary that hints at the flavor of recent mathematical developments. Even if the actual content may be difficult, however, the exciting stories of the people, developments, results, and applications deserve coverage. These stories can add life to school mathematics and encourage our students to join in the fun.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.95-98
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• 2008

Temperature difference energy is a good energy source replacing the fossil fuels. In the study, we classified the temperature difference energy as 4 types by the source & using method. For the understanding economic property of temperature difference energy, we tried simle economic analysis. As the result, Pay back period of 4 case of the temperature difference energy are from 1.23 to 12.65 years. Major factors influenced economic effect are operation time and energy user distance from the temperature difference energy source. If we can select optimal capacity and look for more effient energy users, Temperature difference energy play a important role of replacing fossil energy. So, for dess emination of temperature difference energy, we suggest that temperature difference energy must be included in renewable energy. Applying the effective methods among various promotion program of renewable energy policy, utilization of temperature difference energy could be activated.

• 한국수학사학회지
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• 제32권1호
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• pp.1-15
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• 2019

We divide the timeline of the history of Finsler geometry, which dates back to Riemann's inaugural lecture in 1854, into three periods (hibernation, hiatus, rebirth) and we study formation of Romanian Finsler school around Iasi, Romania during the hiatus period. We look for the history centered around Radu Miron who is a third generation geometer of Iasi University and the mathematical heritage there through five generations. We also investigate mathematical impact of T. Levi-Civita, D. Hilbert, ${\acute{E}}$ Cartan who are considered as top mathematicians at their time.

• 복식문화연구
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• 제25권3호
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• pp.340-358
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• 2017

The purpose of this study is to fundamentally examine the vests of the robes "Daeraebok" and "Soraebok" of the Korean Empire from the 1876 Port Opening to the 1910 annexation of Korea to Japan. Among the collections of different robes of the Korean Empire which belong to various universities and institutions, only the vests were surveyed. The shape of the vests in the Korean Empire were single-breasted and double-breasted. Most V-necklines and vests with a shawl collar look like a tailored collar, where the collar outline was shaped like a notched and picked collar, which is a mix of the step collar and roll collar of the 19th century. The rear center line was not flat, but inclined to a triangle. All vests of the robe Daeraebok were equipped with gold buttons, and those of the robe Soraebok had black satin buttons. The tailoring characteristic is that the front has a different material (dark black wool) from the back (black silk). This characteristic is expected to be an important basic piece of information in the restoration and reproduction of the vest, which was worn during the imperial period, especially to reveal its shape, characteristics and composition. This characteristic can also be used as data of cultural contents based on Korean modern history.

• The Journal of Asian Finance, Economics and Business
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• 제8권7호
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• pp.671-679
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• 2021

House ownership is considered as one of the important pre-conditions for marriage in China. Given that gender imbalance is a prominent issue in the country, competition for marriage partners might motivate males to look for a house and probably bigger and more expensive house. This is believed to have caused house price hikes in recent years. This study aims to investigate the impact of gender imbalance on house prices using data from 30 provinces in China for the 2000-2017 period. The results based on the generalized method of moments (GMM) estimations show that house price is strongly influenced by gender imbalance. However, there is no evidence to support differential effects across eastern and mid-western regions. One potential reason is that pre-marriage house ownership has become a common culture for the whole community and therefore it does not vary significantly across regions. There are several important policy implications. Firstly, the issues should be addressed by the policymakers at national level and not regional level. Secondly, the government should intervene to bring back gender ratio to its normal level. Finally, the government should limit the number of houses people can buy and increase the supply of houses in the market.