• 보건교육건강증진학회지
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• 제26권1호
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• pp.93-104
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• 2009

Objectives: Although Asian immigrants have lower rates of smoking and binge drinking than other ethnics in the US, Korean Americans have the highest rate of Asian immigrants. This study, therefore, compared with the rates and examined the predictors of smoking and binge drinking by gender and ethnicity among Asian immigrants in California. Methods: In 2001 and 2003, California Health Interview Survey (CHIS) were conducted in English and their original languages with Asian immigrants residing in 58 Counties and 3 Cities, California. We performed analysis to find out the differences of smoking and binge drinking rates using the secondary data, CHIS 2001 and 2003. Multiple logistic regression analysis for survey data identified predictors of smoking and binge drinking behaviors by gender and ethnicity. Results: Korean American males (35.4%) and Japanese American females (15.4%) had higher rates of smoking prevalence compared with other Asian immigrants in California. In binge drinking, 26.5% of male and 8.1% of female among Korean Americans were binge drinker, and the rates were the top with Asian Americans who had lived in California. It showed the remarkable gap between gender of smoking and binge drinking among Vietnamese immigrants, whereas not the striking difference among Japanese Americans. In multiple regression models, age, educational level, occupation, marital status, English proficiency, and health insurance coverage remained significant for smoking and binge drinking behaviors(P<0.05). Even though the time in the US was not significant, it seemed to be related to educational level and English proficiency. In particular among female, smoking and binge drinking behaviors were associated with acculturation. Conclusion: Although Asian Americans had shared with American culture since they had immigrated in the US, they had significantly different prevalence rates of smoking and binge drinking based on gender and ethnicity. Therefore, future efforts should be focused on understanding differences by ethnicity and target at high-risk subgroups. To achieve this, it needs to develop the educational materials in Korean and their original languages.

• Journal of Communications and Networks
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• 제5권4호
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• pp.290-302
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• 2003

Ultra wide band (UWB) radio has recently attracted increased attention due to its expected unlicensed operation, and potential to provide very high data rates at relatively short ranges. In this article we briefly describe some main candidate multiple access and modulation schemes for UWB communications, followed with their power spectral density calculation and properties. We also present some illustrative capacity results, and provide a discussion of the impact of network topology on multiple access capacity.

• Journal of the korean society of oceanography
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• 제38권4호
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• pp.157-165
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• 2003

In order to understand the characteristics of sedimentary environments in Ulleung Basin of the East Sea (Sea of Japan), three sediment cores were taken with a box corer during R/V Tamyang cruise in October 1999. Activities of $^{7}Be,{\;}^{210}Pb,{\;}^{226}Ra,{\;}^{234}Th,{\;}^{238}{\;}and{\;}^{137}Cs$ in sediment samples were determined by non-destructive gamma-ray spectrometry. Rates of sedimentation and particle mixing were estimated by best fitting an advection­diffusion particle mixing model to the data of $^{7}Be,{\;}^{234}Th,{\;}and{\;}^{210}Pb$. Estimated sedimentation rates were 0.06-0.08 cm/yr and particle mixing rates were $0.13-0.65{\;}\textrm{cm}^2/yr$. The use of multiple tracers in our study prevented us from probable up to 38% overestimation of sedimentation rates.

• 한국농공학회지
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• 제30권1호
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• pp.50-62
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• 1988

This study refers to the development of a hydrologic model simulating daily inflow and release rates for irrigation reservoirs. A daily - based model is needed for adequate operation of an irrigation reservoir sufficing the water demand for paddy fields which is closely related to meteorological conditions. Inflow rates to a reservoir need to be accurately described, which may be simulated using a hydrologic model from daily rainfall data. And the objective of this paper is to develop, test, and apply a hydrologic model for daily runoff simmulation. A well - known tank model was selected and modified to simulate daily inflow rates. The model parameters were calibrated using observed runoff data from twelve watersheds, Relationships between the parameters and the watershed characteristics were derived by a multiple regression analysis. The simulation results were in agreement with the data. The inflow model was found to simulate low flow conditions more accurately than high flow conditions, which may be adequate for water resources utilization.

• Journal of information and communication convergence engineering
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• 제6권3호
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• pp.353-357
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• 2008

One objective in developing the next generation of wireless communication systems is to increase data rates and reliability. A promising way to achieve this is to combine multiple-input and multiple-output signal processing with a space-time coding scheme, which offers higher coding and diversity gains and improves the spectrum efficiency and reliability of a wireless communication system. It is noted, however, that time delay differences and phase differences among different channels increase symbol interference and degrade system performance. In this letter, we investigate phase differences and their effects on multiple-input and multiple-output systems, and propose a compensation algorithm for the Rayleigh fading model to minimize their effects.

• ETRI Journal
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• 제28권5호
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• pp.680-683
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• 2006

One objective in developing the next generation of wireless communication systems is to increase data rates and reliability. A promising way to achieve this is to combine multiple-input and multiple-output signal processing with a space-time coding scheme, which offers higher coding and diversity gains and improves the spectrum efficiency and reliability of a wireless communication system. It is noted, however, that time delay differences and phase differences among different channels increase symbol interference and degrade system performance. In this letter, we investigate phase differences and their effects on multiple-input and multiple-output systems, and propose a compensation algorithm for the Rayleigh fading model to minimize their effects.

• 대한전자공학회논문지TC
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• 제47권2호
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• pp.40-46
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• 2010

다중 사용자 MIMO (Multiple-Input Multiple-Output) 시스템에서 협력적 전송을 기반으로 한 협력적 PF (Proportional Fair) 스케쥴러를 사용하는 경우 사용자 평균 전송률의 로그 합 성능의 개선이 가능하다. 단일 셀 기반의 기존 PF 알고리듬은 여러 채널 환경에 대하여 그 성능이 평가되어 왔으나 여러 개의 기지국들이 스케쥴링에 참여하여 한 프레임 동안 다수의 사용자를 스케쥴링하는 알고리듬의 제시 및 성능 평가는 많은 연구가 필요한 상태이다. 본 논문에서는 서로 다른 셀에 속하는 인접한 세 섹터에 위치한 기지국들이 사용자들의 채널 정보를 교환하여 다중 사용자에게 자원을 할당하는 협력적 PF 스케쥴러를 분산 다중 사용자 MIMO 시스템에 적용하고 사용자 평균 전송률의 로그 합 성능을 평가한다. 또한 그 성능을 기지국 간의 채널 정보 교환 없이 자원을 할당할 사용자를 각자 선택하는 병렬적 PF 스케쥴러와 자원 할당 시 선택할 수 있는 동시 사용자 그룹의 모든 조합을 검색하는 full-search 협력적 PF 스케쥴러의 평균 전송률의 로그 합 성능과 비교 분석한다. 본 연구에 적용된 협력적 PF 스케쥴러는 하위 사용자 평균 전송률의 로그 합 성능 측면에서 병렬적 PF 스케쥴러보다 우수한 성능을 보인다. 또한 모든 조합을 검색함으로서 가장 큰 평균 전송률의 로그 합 성능을 나타내는 full-search 협력적 PF 스케쥴러의 성능의 대부분을 달성하면서도 연산 복잡도를 크게 감소시킨다.

• Journal of Korean Neurosurgical Society
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• 제64권4호
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• pp.486-494
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• 2021

The growth of pulsed electromagnetic field (PEMF) therapy and its progress over the years for use in post-operative bone growth has been revolutionary in its effect on bone tissue proliferation and vascular flow. However, further progress in PEMF therapy has been difficult due to lack of more evidence-based understanding of its mechanism of action. Our objective was to review the current understanding of bone growth physiology, the mechanism of PEMF therapy action along with its application in spinal surgery and associated outcomes. The authors of this review examined multiple controlled, comparative, and cohort studies to compare fusion rates of patients undergoing PEMF stimulation. Examining spinal fusion rates, a rounded comparison of post-fusion outcomes with and without bone stimulator was performed. Results showed that postoperative spinal surgery PEMF stimulation had higher rates of fusion than control groups. Though PEMF therapy was proven more effective, multiple factors contributed to difficulty in patient compliance for use. Extended timeframe of treatment and cost of treatment were the main obstacles to full compliance. This review showed that PEMF therapy presented an increased rate of recovery in patients, supporting the use of these devices as an effective post-surgical aid. Given the recent advances in the development of PEMF devices, affordability and access will be much easier suited to the patient population, allowing for more readily available treatment options.

• Journal of Preventive Medicine and Public Health
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• 제41권4호
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• pp.279-286
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• 2008

Objectives: This study was performed to provide the basic data for establishing countermeasures for preventing injury by analyzing the incidence rates, the risk factors, the characteristics of the injury and the utilization of medical care for mild injury that lasted for two weeks. Methods: We examined the injury survey data among the National Health and Nutrition Survey data. The definition of mild injury that lasted for two weeks was that the injury that caused pain at least once a day for two weeks or the injury for which the usual daily activity of the injured person was severely affected. We used statistical analysis methods such as chi-square test and multiple logistic regression analysis. Results: The incidence rate of injury that lasted for two weeks was 4.7 per 1,000 persons. On the multiple logistic regression, the children and adolescents (OR=3.80, 95%CI=1.63-8.84) had higher rates of injuries than the adults, and the middle and high school (OR=0.51, 95%CI=0.31-0.85) and college(OR=0.34, 95%CI=0.17-0.68) students had lower rates of injuries than the elementary school students. The unemployed (OR=0.39, 95%CI=0.20-0.73) and others (OR=0.38, 95%CI=0.21-0,70) had lower rates of injuries than the blue collar workers. The major causes of injuries were found to be falling and slipping, and the most prevalent place of occurrence was near or at home. Conclusions: A prevention program needs to be developed and continuous education must be offered to the children, adolescents and blue collar workers.

• Korean Journal of Mathematics
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• 제28권1호
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• pp.1-7
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• 2020

A partition X describes that there exists α_i kinds of alleles occurring i loci for each i. All genes have multiple alleles, i.e., they exist in more than two allelic forms, although any one diploid organism can carry no more than two alleles. The number of possible genotypes in a multiple allel series depends on the number of alleles. We will deal with an n locus model in which mutation and gene conversion are taken into consideration. In this paper, we firstly find the probability p_n(x) of genotype $$p_{n+1}(x)=p_n(x){\sum\limits_{k=1}^{r}}q_{kx}p_n(k)$$ with the rates of mutation and gene conversion. Also we find the probability of genotype without the rates of mutation and gene conversion and we apply this probability to two examples.