• Journal of Preventive Medicine and Public Health
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• v.40 no.5
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• pp.381-387
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• 2007

Objectives: This study was conducted in order to determine how the association between socioeconomic position(SEP) and health status changes with age among Seoul residents aged 25 and over. Methods: We utilized the 2001 and 2005 Seoul Citizens Health Indicators Surveys. We used self-rated 'poor' health status as an outcome variable, and family income as an indicator of SEP. In order to characterize the differential effects of socioeconomic position on health by age, we conducted separate multivariate analyses by 10-year age groups, controlling for sociodemographic covariates. In order to assess the relative health inequality across socioeconomic groups, we estimated the Relative Index of Inequality (RII). Results: The risk of 'poor health' is significantly high in low family income groups, and this increased risk is seen at all ages. However, the magnitude of relative socioeconomic inequality in health, as measured by the odds ratio and RII, is not identical across age groups. The difference in health across income groups is small in early adulthood (ages 25-34), but increases with age until relatively late in life (ages 35-64). It then decreases among the elderly population (ages more than 65). When the RII reported in 2005 is compared to that reported in 2001, RII can be seen to have increased across all ages, with the exception of individuals aged 25-34. Conclusions: The magnitude of health inequality is the greatest during mid- to late adulthood (ages 45-64). In addition, health inequalities have worsened between 2001 and 2005 across all age groups after economic crisis.

• Journal of Biosystems Engineering
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• v.30 no.2 s.109
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• pp.127-133
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• 2005

Precision tillage is designed to till lands variably according to their firmness. Therefore, it is necessary to measure soil firmness in fields and present it in a form with which the variable tillage on be performed. Such forms may be classified into two categories: sensor-based and map-based forms. The map-based approach appears to be inevitable until the technology develops high enough to secure the sensor-based approaches. The first step for map-based precision tillage may be to develop a tillage recommendation map. In this study, a tractor-mountable automatic soil firmness measurement system was developed to construct a cone index map. The system is comprised of three ASAE Standard cone penetrometers and a hydraulic unit for controlling operation of the penetrometers. The system is designed to conduct stop-and-go measurements in fields. The measurements from the three penetrometers are transferred to a microcomputer and the average cone index was calculated. This average cone index was taken as soil firmness of the location where the measurement was made. The cone indices thus determined were used to construct a cone index map using the ArcView software. The system also displays the soil penetration resistance, cone index and soil depth as the cone penetrates into the soil. The field performance of the system was evaluated and the cone index maps at different depths were also presented.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.406-414
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• 2012

The purpose of this study tries to find some competitive marketing strategies of the hotel wedding service. In order to do that, this study positively analyzes the followings: First, the causality between the qualities of hotel wedding service and customer satisfaction. Second, the word-of-mouth intention on the causality. The study bases on the survey that has been conducted for five-star hotel customers in Seoul. 20 questionnaires were circulated in each for 12 five-star hotels in Seoul. The number of sample used in this study is 315. This study draws two conclusions from the above survey analysis: First, the hotel wedding service influences customer satisfaction. Second, customers' word-of-mouth plays a meaningful controlling role between the qualities of hotel wedding service and customer satisfaction. Regarding the results and limits of this study, more researches are needed into the products of hotel wedding service and the sample segmentation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11C
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• pp.51-63
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• 2001

According to the popular use of the multimedia services in distributed environments, the need for the variable multimedia communication technologies have been presented today. In order to support the efficient transmission multimedia streams, the multicasting, and the interoperability between multimedia applications in distributed environments, the development of the open exclusive multimedia communication systems and the provision of the control and management methodologies for media streams have been required. In order support the realtime transmission of multimedia stream in distributed environments. the protocols such as RTP, RSVP, and RTSP have been standardized. For supporting the interoperability between multimedia applications and the control and management of streams, the distributed processing platforms such as CORBA by OMG and DSM-CC by DAVIC were published. In this paper, we introduce the CORBA-based distributed multimedia communication system which support the realtime transmission, control, and management of multimedia streams and provide the interoperability between multimedia applications. Finally, we present the QoS measurement results by the interoperability between our systems and VoD systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10C
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• pp.820-828
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• 2008

In order to achieve high coding efficiency, H.264/AVC video coding standard adopts the techniques such as variable block size coding, motion estimation with quarter-pel precision, multiple reference frames, rate-distortion optimization, and etc. However, these coding methods have a defect to greatly increase the complexity for motion estimation. Particularly, from multiple reference frame motion estimation, the computational burden increases in proportion to the number of the searched reference frames. Therefore, we propose the method to reduce the complexity by controlling the number of the searched reference frames in motion estimation. Proposed algorithm uses the optimal reference frame information in both $P16{\times}16$ mode and the adjacent blocks, thus omits unnecessary searching process in the rest of inter modes. Experimental results show the proposed method can save an average of 57.31% of the coding time with negligible quality and bit-rate difference. This method also can be adopted with any of the existing motion estimation algorithm. Therefore, additional performance improvement can be obtained.

• Korean Journal of Optics and Photonics
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• v.22 no.1
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• pp.5-9
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• 2011

There are technical difficulties in measuring the numerical apertures of multi-mode gradient-index plastic optical fibers (GI-POFs) due to their strong speckle noise originating from dopants, non-uniformity of gradient-index profile, and multi-mode interference. Therefore, we propose a new method of obtaining the numerical aperture by controlling the size of the incident laser beam and measuring the numerical aperture of GI-POF. The results show that we can get a value for the numerical aperture of GI-POF very similar to that measured by the conventional method. We can also obtain the optimum launching condition of input beam and maximum coupling efficiency.

• Korean Educational Research Journal
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• v.40 no.3
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• pp.1-16
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• 2019

The purpose of this study is to explore the factors related to high school students 'academic stress. This study uses data from KEDI's(KELS 2013 6th). The data were analyzed using descriptive statistics, Pearson correlation analysis, and hierarchical analysis using the SPSS Statistics program. The results of the study are as follows. First, personal factors, social support factors, and family-related factors showed statistically significant correlation with academic stress. Second, personal factors, family-related factors, and social support factors were all found to have statistically significant effects on high school students' academic stress. After controlling the personal factors and family-related factors, the social support factors further explain the academic stress of high school students by two percent, and the most influential variable among social support factors was the relationship with their parents.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.111-120
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• 2016

PCAOB conducts the direct supervision for the PCAOB registered accounting firm. Therefore, if an accounting firm is registered with the PCAOB, it will thoroughly manage for their quality management systems. The registered auditor can be expected to have better quality of the audit. This study carried out the analysis using the audit fee which proxies for audit quality. The results of analysis are as follows. After controlling for foreign accounting firms affiliated status, company size, risky assets, leverage, ROA, and market-related variables, PCAOB is a significant explanatory variable for the audit fees. The results of this study support the hypothesis that PCAOB-registered auditors will provide a good audit quality.

• Korean Journal of Social Welfare
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• v.47
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• pp.206-242
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• 2001

A survey research was conducted for a sample of 306 adult children who have an elderly parent or both parents alive. The purpose of the research was to test a structural equation model which specified the effects of early family relationships on comtemporary relationships and assistance patterns between adult children and their parents. The data were analyzed using EQS for Windows 5.7, utilizing maximum likelihood method. The results showed that early family relationships affected filial concern first, which in turn affected the level of assistance provided by adult children for elderly parents. No direct effect has been found between early family relationships and the level of assistance by adult children for elderly parents. Filial concern was played as an intervening variable. Early family relationships gave no direct effects to adult children's intention to assist their parents. Here again, filial concern was played as an intervening factor. Adult children's intention to assist their parents had not been led directly to provision of actual support to parents by their adult children. Thus, it was identified that intention to support is one thing, and the actual support is another. Controlling for the effects of filial concern, overall, early family relationship patterns gave no differential effects to the different aspects of support provided to parents by their adult children. On the basis of these results, this paper provided both discussions and suggestions for some strategies of intervention in the present family relationships in order for the inter-generational exchange of supports to happen in the future.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.590-597
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• 2016

We designed the multiple scattering points generation system to simulate an actual situation of target signal for high range resolution radar system. This provides replicating the target signals and controlling the status of target signals for radar system. This is composed transmit antenna and multi target generator. Transmit antenna is waveguide array antenna and multi target generator has signal distribution module and control & power module. Multi target generator is able to provide the high isolation and variable output power. Moreover, in order to monitor all output signals of the multi target generator, the flows of signals are programed in control & power module. The performance is demonstrated using experimented results of high range resolution radar.