모바일 그래픽 가속기용 부동소수점 절사 승산기 설계

조용성,이용환,Cho, Young-Sung,Lee, Yong-Hwan 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.3

모바일 통신 서비스의 발전과 반도체 기술의 발달로 모바일 기기에 멀티미디어 서비스와 2D/3D 게임과 같이 고수준의 그래픽 처리를 필요로 하는 콘텐츠가 가능하게 되었다. 모바일 기기는 특성상 더욱 작은 칩 면적과 저전력 소비의 조건이 만족되어야 하며, 본 논문에서는 이러한 모바일 기기에 적용 가능한 2D/3D 벡터 그래픽 처리용 부동소수점 절사형 승산기를 설계한다. 본 논문의 승산기는 기본적으로 radix-4 Booth 인코딩을 적용하고, 면적과 전력소모를 줄이기 위하여 절사방식을 사용한다. 구현된 절사형 승산기는 평균 퍼센트 오차가 0.00003% 정도로 모바일 기기에 충분히 적용가능하다. 승산기는 0.35um CMOS 셀 라이브러리를 이용하여 논리 합성되었고, 그 결과 절사되지 않은 기존의 radix-4 Booth 승산기에 비해 게이트 수가 약 33.8%정도 감소하였다. As the mobile communication and the semiconductor technology is improved continuously, mobile contents such as the multimedia service and the 2D/3D graphics which require high level graphics are serviced recently. Mobile chips should consume small die area and low power. In this paper, we design a truncated floating-point multiplier that is useful for the 2D/3D vector graphics in mobile devices. The truncated multiplier is based on the radix-4 Booth's encoding algorithm and a truncation algorithm is used to achieve small area and low power. The average percent error of the multiplier is as small as 0.00003% and neglectable for mobile applications. The synthesis result using 0.35um CMOS cell library shows that the number of gates for the truncated multiplier is only 33.8 percent of the conventional radix-4 Booth's multiplier.

정.동적 하중에 의한 비압밀비배수 보강화강풍화토의 전단강도 특성

조용성,구호본,박인준,김유성,Cho, Yong-Sung,Koo, Ho-Bon,Park, Inn-Joon,Kim, You-Seong 한국지반공학회 2006 한국지반공학회논문집 Vol.22 No.7

When enforced earth is used for the retain wall and four walls, the most important thing would be how to maximize the land utilization. Accordingly, in case of enforced earth, we pile up the minimal height of earth ($20{\sim}50\;cm$) and harden the earth using a static dynamic hardening machine. In this paper, we tried to analyze and compare the stress transformation characteristics of reinforced weathered granite soil with geosynthetics when repetitive load is added to the enforced earth structure and when static load is added. The result is that the cohesion component of the strength increased greatly and the friction component decreased slightly.

3차원 GIS 모델을 활용한 공동 주택 단지의 일조율과 천공율의 상관관계에 관한 연구 - 중계동 아파트 62개 단지를 대상으로 -

조용성,원제무,Cho, Yong-Sung,Won, Jae-Mu 한국주거학회 2011 한국주거학회 논문집 Vol.22 No.1

There are various kinds of Large-Scale apartment sites in Seoul. There are more households in apartment sites than single family houses. Nowadays, it is easy to find a lot of apartment sites built in the style of a high rise building. On the matter of space, a building is influenced by the buildings near it. The influence a building has to another is different in both qualitative and quantitative ways. Therefore, in the case of apartment sites, the environmental surroundings of each household is affected by the nearby buildings. For these reasons, the environment is having more and more influence on the price of each household in apartment sites. This paper has defined Sunshine and Sky as the major environmental elements. In order to be analyzed, they have to be measurable. Thus, there are two types of variables in environmental surrounding of apartment sites, -the Duration of Sunshine and the possible amount of visible Sky- the significant variables which influence the housing price. This paper deals with the relationship between the possible duration of sunshine and the possible amount of sky a household is visible to. It focused on 62 different apartment sites which were built after 1990. It is based on the 3-dimensional Geographic Information System & Computer Aided Engineering for analyzing the sunshine simulation and the viewing simulation. This paper will be helpful for designing the apartment sites considering the balance between sunshine and sky.

대기오염 노출이 첫 출산아 저체중에 미치는 영향에 관한 연구 -서울지역 1999년~2003년 출생코호트를 중심으로-

조용성,손지영,이종태,Cho, Yong-Sung,Son, Ji-Young,Lee, Jong-Tae 한국환경보건학회 2007 한국환경보건학회지 Vol.33 No.4

Recent epidemiologic studies show that gestational exposure to air pollution adversely affects pregnancy outcomes including low birth weight in preform birth. In this study, we evaluated the effect of air pollutants on LBW (low birth weight) on firstborn fetus throughout the gestational period using the birth cohort between 1999 and 2003 in Seoul. Using birth cohort data from the National Statistics Office of Korea we identified 288,346 firstborn births (excluded missing data on lack of information for birth weight and discordance between residential and certificated address from a total of 316,451) during 1999 to 2003 with complete covariate (gender, parity, date of birth, gestational age, parental age and educational level, maternal occupation etc.) and maternal residential history data. Our subjects were defined as more than 37 weeks and less than 44 weeks of completed gestation and we identified 5,457 persons (1.89%) by low birth weight (<2.5 kg) in this study. Using logistic regression, we estimated the risk of mean (entire pregnancy and trimester period) air pollution concentrations for CO, $O_3,\;PM_{10},\;NO_2\;and\;SO_2$. In terms of trimester-specific exposure, we found that some air pollutants exposure in each trimester would increase the risk for LBW. Results also showed that the effect size of air pollutants exposure during the first and third trimester is higher than during the second trimester. In all trimester, the estimated risk of LBW was 1.831 (95% CI=1.573-2.132) with unit increase for CO, 1.139 (95% CI=1.107-1.172) for 50, and 1.009 (95% CI=1.001-1.017) for $O_3$. Our results suggest that exposure during the gestation period to relatively low levels of some air pollutants may be associated with a reduction in birth weight on first-born fetus. These findings implicate the effective risk management strategies should be applied to minimize the public health impacts for pregnant women.

메타분석을 적용한 전국 7개 대도시의 대기오염과 일일사망발생의 상관성 연구(1998년$\sim$2001년)

조용성,이종태,손지영,김윤신,Cho, Yong-Sung,Lee, Jong-Tae,Son, Ji-Young,Kim, Yoon-Shin 한국환경보건학회 2006 한국환경보건학회지 Vol.32 No.4

This study is performed to reexamine the association between ambient air pollution and daily mortality in seven major cities of Korea using a method of meta-analysis with the data filed for the period 1998-2001. These cities account for half of the Korean population (about 23 million). The observed concentrations of carbon monoxide (CO, mean=1.08 ppm), ozone ($O_3$, mean=33.97 ppb), particulate matter less than 10 ${\mu}m$ ($PM_{10},\;mean=57.11\;{\mu}g/m^3$), nitrogen dioxide ($NO_2$, mean=25.09 ppb), and sulfur dioxide ($SO_2$, mean=9.14 ppb) during the study period were at levels below Korea's current ambient air quality standards. Generalized additive models were applied to allow for the highly flexible fitting of seasonal and long-term time trends in air pollution as well as nonlinear associations with weather variables, such as air temperature and relative humidity. Also, we calculated a weighted mean as a meta-analysis summary of the estimates and its standard error. In city-specific analyses, an increase of $41.17{\mu}g/m^3(IQR)\;of\;PM_{10}$ corresponded to $1{\sim}12%$ more deaths, given constant weather conditions. Like most of air pollution epidemiologic studies, this meta-analysis cannot avoid fleeing from measurement misclassification since no personal measurement was taken. However, we can expect that a measurement bias be reduced in district-specific estimate since a monitoring station is better representative of air quality of the matched district. Significant heterogeneity was found for the effect of all pollutants. The estimated relative risks from meta-like analysis increased compared to those relative risks from pooled analysis. The similar results to those from the previous studies indicated existence of health effect of air pollution at current levels in many industrialized countries, including Korea.

순차적 근사화 기법을 이용한 VI 성능향상설계

조용성(Yong-Sung Cho),김홍규(Hong-Kyu Kim),곽창섭(Chang-Seob Kwak),송기동(Ki-Dong Song) 대한전기학회 2013 대한전기학회 학술대회 논문집 Vol.2013 No.7

송전선로 주변과 비주변 초등학생을 대상으로 극저주파 자기장 노출과 뇨중 성장 호르몬 분비량간의 상관성 연구

조용성(Yong-Sung Cho),김윤신(Yoon-Shin Kim),이종태(Jong-Tae Lee),최성호(Sung-Ho Choi),홍승철(Seung-Cheol Hong),장성기(Seong-Ki Jang) 한국실내환경학회 2005 한국실내환경학회지 Vol.2 No.1

본 연구는 송전선로 주변과 비 주변 초등학생을 대상으로 극저주파 자기장 노출량을 비교하고 극저주파 자기장 노출과 성장호르몬 분비량간의 상관성을 조사하기 위해 2003년 12월부터 2004년 4월까지 28명의 송전선로 주변 초등학생과 60명의 비 주변 초등학생을 대상으로 극저주파 자기장 24시간 개인노출량을 평가하였으며, 극저주파 자기장 노출 영향 지표로서 성장호르몬 분비량을 조사하였다. 본 연구결과를 요약하면 다음과 같다. 송전선로 주변과 비 주변 초등학생의 일반적 특성을 조사하였는데, 가정내 체류시간과 수면시간 및 식습관 중 육류섭취와 전기장판 사용 현황에서는 통계적으로 유의한 차이가 나타나지 않았으나 학교생활 시간과 송전선로와 거주지까지의 거리 및 패스트푸드점 이용을 통한 식습관에서는 통계적으로 유의한 차이를 나타내었다. 또한 가정내 전기제품 수에서도 통계적으로 유의한 차이를 나타내었다. 신체지수량의 경우에는 송전선로 주변학생의 경우에는 평균 20.35㎏/㎡으로 정상범위를 나타내었으나 비 주변 거주 학생의 경우에는 평균 18.71㎏/㎡으로 다소 낮은 지수를 나타내었다. 극저주파 자기장 개인노출 수준을 24시간과 가정생활 및 학교생활별로 비교한 것으로서 24시간동안 송전선로 주변 학생의 경우에는 평균 0.365 μT의 높은 자기장 수준을 나타내었으며, 특히 학교생활의 경우에는 0.796μT로 매우 높은 자기장 수준을 나타내었다. 송전선로 비 주변 학생의 경우에는 주변학생에 비해 1/10 이하의 자기장 수준을 나타내었으며 특히 학교생활 중의 자기장 노출수준에서는 0.02μT로 주변 학생에 비해 약 1/40로 낮은 자기장 수준을 나타내었다. 성장호르몬과 극저주파 자기장 노출수준간의 상관성을 분석하였는데, 매우 낮은 역상관성을 나타내었다. 또한 성장호르몬 분비량에 영향을 줄 수 있는 요인별 차이를 평가하였는데, 송전선로 주변 초등학생의 성장호르몬 분비량은 0.88ng/g-cr으로 비 주변 초등학생의 성장호르몬 분비량 1.14ng/g-cr보다 통계적으로 유의하게 낮게 나타났다(p<0.05). 한편, 송전선과 거주지까지의 거리가 100m 이내인 초등학생의 성장호르몬 분비량은 0.99ng/g-cr으로 100m 이상인 초등학생의 1.09ng/g-cr에 비해 통계적으로 유의하지는 않았으나 낮은 성장호르몬 분비량을 나타내었다(p>0.05). 본 연구에서는 극저주파 자기장 노출과 성장호르몬 분비량간의 음의 관련성이 나타났으나 분석상의 제한점으로 인해 향후 이에 대한 추가적인 연구가 필요함을 제안할 수 있었다. The present study investigated the hypothesis that a extremely low frequency magnetic field (ELF-MF) partially suppresses the synthesis of human growth hormone (HGH) in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 μT, whereas the levels for the primary schoolchildren living away from overhead transmission power line was 0.05 μT. From simple analyses, the mean growth hormone levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, and statistically significant differences in the levels of the growth hormone (p = 0.0316), whereas not statistically significant differences in the levels of the growth hormone related to the distance from residence to power line less and more than 100 m by cut-off point (p = 0.4017). In conclusion, these results may indicate that urinary levels of nocturnal growth hormone are altered in primary schoolchildren exposed to extremely low frequency magnetic field at overhead transmission power line.

진공차단기 접점설계를 위한 해석툴 개발

조용성(Yong-Sung Cho),김홍규(Hong-Kyu Kim),곽창섭(Chang-Sub KWAK),송기동(Ki-Dong Song) 대한전기학회 2013 대한전기학회 학술대회 논문집 Vol.2013 No.4

인천시 대기오염과 일별 사망의 상관성에 관한 시계열적 연구(1998년~2001년)

조용성(Yong-Sung Cho),이종태(Jong- Tae Lee),김윤신(Yoon-Shin Kim),현연주(Youn-Joo Hyun),문정숙(Jeong-Suk Moon) 대한환경위생공학회 2003 대한환경위생공학회지 Vol.18 No.3

This study is performed to examine the relationship between air pollution exposure and mortality in Incheon for the years of 1998 - 2001. Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of seasonal trend, air temperature, humidity, and day of the week as confounders in a nonparametric approach. Daily death counts were associated with CO(l day before), O₃(2 day before), PM10(l day before), NO₂(l day before), SO₂(l day before). Increase of 32.21㎨(interquartile range) in PM10 was associated with 1.9 % (95% CI = 0.8 % - 2.9 %) increase in the daily number of death. This effect was greater in children (less than 15 aged) and elderly(more than 65 aged). We concluded that Incheon had 2 - 4 % increase in mortality in association with IQR in air pollutants. Daily variations in air pollution within the range currently occurring in Incheon might have an adverse effect on daily mortality. These findings also support the hypothesis that air pollution, at levels below the current ambient air quality standards of Korea, is harmful to sensitive subjects, such as children or elderly.

개인 취향에 맞는 음악 선곡 시스템

조용성(Yong-Sung Cho),강은영(Eun-Young Kang),손영선(Young-Sun Sohn) 한국지능시스템학회 2002 한국지능시스템학회 학술발표 논문집 Vol.12 No.2