• Health Policy and Management
• /
• v.26 no.1
• /
• pp.71-78
• /
• 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.

• Journal of the Korea Furniture Society
• /
• v.12 no.1
• /
• pp.91-101
• /
• 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.

• Journal of the Korean Society of Costume
• /
• v.50 no.3
• /
• pp.117-131
• /
• 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'.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.5
• /
• pp.62-70
• /
• 2007

In this paper, the boost Power Factor Correction(PFC) technique for Direct Torque Control(DTC) of brushless DC motor drive in the constant torque region is implemented on a TMS320F2812DSP. Unlike conventional six-step PWM current control, by properly selecting the inverter voltage space vectors of the two-phase conduction mode from a simple look-up table at a predefined sampling time, the desired quasi-square wave current is obtained, therefore a much faster torque response is achieved compared to conventional current control. Furthermore, to eliminate the low-frequency torque oscillations caused by the non-ideal trapezoidal shape of the actual back-EMF waveform of the BLDC motor, a pre-stored back-EMF versus position look-up table is designed. The duty cycle of the boost converter is determined by a control algorithm based on the input voltage, output voltage which is the dc-link of the BLDC motor drive, and inductor current using average current control method with input voltage feed-forward compensation during each sampling period of the drive system. With the emergence of high-speed digital signal processors(DSPs), both PFC and simple DTC algorithms can be executed during a single sampling period of the BLDC motor drive. In the proposed method, since no PWM algorithm is required for DTC or BLDC motor drive, only one PWM output for the boost converter with 80 kHz switching frequency is used in a TMS320F2812 DSP. The validity and effectiveness of the proposed DTC of BLDC motor drive scheme with PFC are verified through the experimental results. The test results verify that the proposed PFC for DTC of BLDC motor drive improves power factor considerably from 0.77 to as close as 0.9997 with and without load conditions.

• Journal of Astronomy and Space Sciences
• /
• v.24 no.4
• /
• pp.261-268
• /
• 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.

• Journal for History of Mathematics
• /
• v.17 no.1
• /
• pp.69-86
• /
• 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
• /
• 2008.05a
• /
• pp.95-98
• /
• 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.

• Journal for History of Mathematics
• /
• v.32 no.1
• /
• pp.1-15
• /
• 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.

• The Research Journal of the Costume Culture
• /
• v.25 no.3
• /
• pp.340-358
• /
• 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
• /
• v.8 no.7
• /
• pp.671-679
• /
• 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.