A Study on the Flying Stability of Optical Flying Head on the Plastic Disks

Sookyung Kim(김수경),Sang-Joon Yoon(윤상준),Dong-Hoon Choi(최동훈),Seung-Yop Lee(이승엽) 한국소음진동공학회 2004 한국소음진동공학회 학술대회논문집 Vol.2004 No.11

A study on the flying stability of optical flying head on the plastic disks

Kim, Sookyung,Yoon, Sang-Joon,Choi, Dong-Hoon,Lee, Seung-Yop IEEE 2005 IEEE transactions on magnetics Vol.41 No.2

In the optical drive system, adopting the optical-flying-type head (OFH) flying on a removable plastic disk, the flying stability of the small OFH should be carefully considered to ensure the reliability for the first surface recording. This study gives two simulation results on the flying stability of the OFH: one is the dependence of the flying height and pitch angle variations on the wavelength and amplitude of disk waviness, and the other is the flying stability of the slider and suspension system during the dynamic load/unload process.

일 지역사회에서 치매환자의 사망률과 위험요인

박수경(Sookyung Park),이준영(Jun-Young Lee),서국희(Guk Hee Suh),장성만(Sung-Man Chang),조맹제(Maeng Je Cho) 대한노인정신의학회 2007 노인정신의학 Vol.11 No.1

Objectives : The aim of this study was to investigate mortality rates and risk factors in dementia patients in a rural cohort. Methods : A total of 114 subjects with clinically diagnosed dementia were followed up for eight years from 1997 to 2005. Their mortality was compared with sociodemographic and clinical variables using the Cox proportional hazards models after adjusting age, sex, and education. Results : During follow-up, the mortality rate of subjects was 80.2% and the mean (SD) duration of survival from at diagnosis to death was 4 years. Mortality in subjects with dementia depended on old age (relative risk [RR] : 1.05;95% confidence interval [CI] : 1.01-1.08), male (RR : 1.61;CI : 1.00-2.59), low Clinical Dementia Rating scale (RR : 1.54;CI : 1.14-2.10), low Activities of Daily Living (RR : 0.72;CI : 0.59-0.89), low Instrumental Activities of Daily Living (RR : 0.83;CI : 0.75-0.92), no physical activity (RR : 0.44;CI : 0.28-0.70), smoking (RR : 1.74;CI : 1.05-2.89). Conclusion : Mortality in dementia depended on age, sex, CDR, ADL, IADL, physical activity, smoking. These findings have important implications that contribute to make the disease management of dementia patients.

Spatial distribution patterns of old-growth forest of dioecious tree Torreya nucifera in rocky Gotjawal terrain of Jeju Island, South Korea

Shin, Sookyung,Lee, Sang Gil,Kang, Hyesoon The Ecological Society of Korea 2017 Journal of Ecology and Environment Vol.41 No.8

Background: Spatial structure of plants in a population reflects complex interactions of ecological and evolutionary processes. For dioecious plants, differences in reproduction cost between sexes and sizes might affect their spatial distribution. Abiotic heterogeneity may also affect adaptation activities, and result in a unique spatial structure of the population. Thus, we examined sex- and size-related spatial distributions of old-growth forest of dioecious tree Torreya nucifera in extremely heterogeneous Gotjawal terrain of Jeju Island, South Korea. Methods: We generated a database of location, sex, and size (DBH) of T. nucifera trees for each quadrat ($160{\times}300m$) in each of the three sites previously defined (quadrat A, B, C in Site I, II, and III, respectively). T. nucifera trees were categorized into eight groups based on sex (males vs. females), size (small vs. large trees), and sex by size (small vs. large males, and small vs. large females) for spatial point pattern analysis. Univariate and bivariate spatial analyses were conducted. Results: Univariate spatial analysis showed that spatial patterns of T. nucifera trees differed among the three quadrats. In quadrat A, individual trees showed random distribution at all scales regardless of sex and size groups. When assessing univariate patterns for sex by size groups in quadrat B, small males and small females were distributed randomly at all scales whereas large males and large females were clumped. All groups in quadrat C were clustered at short distances but the pattern changed as distance was increased. Bivariate spatial analyses testing the association between sex and size groups showed that spatial segregation occurred only in quadrat C. Males and females were spatially independent at all scales. However, after controlling for size, males and females were spatially separated. Conclusions: Diverse spatial patterns of T. nucifera trees across the three sites within the Torreya Forest imply that adaptive explanations are not sufficient for understanding spatial structure in this old-growth forest. If so, the role of Gotjawal terrain in terms of creating extremely diverse microhabitats and subsequently stochastic processes of survival and mortality of trees, both of which ultimately determine spatial patterns, needs to be further examined.

교통 이력자료를 위한 데이터베이스 설계

송수경 ( Sookyung Song ),윤혜정 ( Hyejung Yun ),정수정 ( Sujeong Cheong ),이윤경 ( Yoon-kyung Lee ),남궁성 ( Sung Namgung ),오철 ( Cheol Oh ),이민수 ( Minsoo Lee ) 한국정보처리학회 2007 한국정보처리학회 학술대회논문집 Vol.14 No.1

현재 한국도로공사에서 운영하는 교통 관리 시스템은 일반 사용자에게 실시간 교통 정보를 제공하는 목적으로 만들어졌다. 그러므로 장기간의 교통자료를 모아서 얻은 교통 이력자료를 가지고 분석 및 연구를 수행하는데 제약이 많다. 본 논문에서는 교통 연구자에게 교통 이력자료를 가지고 분석 및 연구를 수행할 수 있는 데이터베이스를 위한 설계 방법을 제안한다.

Harnessing Recombinant DnaJ Protein as Reversible Metal Chelator for a High-Performance Resistive Switching Device

Jang, Sung Kyu,Kim, Sookyung,Salman, Muhammad Saad,Jang, Ji-ryang,Um, Yu Mi,Tan, Lihan,Park, Jin-Hong,Choe, Woo-Seok,Lee, Sungjoo American Chemical Society 2018 Chemistry of materials Vol.30 No.3

<P>A high-performance biomaterial-based resistive switching (RS) device is fabricated by harnessing a thermally denatured protein (hexa-His-tagged recombinant molecular chaperone DnaJ (rDnaJ)) as a switching layer in a Cu/rDnaJ/Pt configuration on SiO<SUB>2</SUB>/Si substrate. The conductivity of the heat-denatured rDnaJ protein layer between the metal electrodes can be reversibly controlled to enable the formation/rupture of conductive Cu filaments by tailoring the metal chelating properties of the amino acid residues in the insulating protein matrix in a pH- and/or redox potential-dependent manner, giving rise to high-performance nonvolatile RS behavior. The rDnaJ-based RS device exhibits extremely low set voltage (∼0.12 V) and reset voltage (∼−0.08 V) with excellent uniformity, along with large memory window (<I>R</I><SUB>HRS</SUB>/<I>R</I><SUB>LRS</SUB> > 10<SUP>6</SUP>) and long retention time (>10<SUP>6</SUP> s). In addition, the rDnaJ RS device, which is fabricated on a flexible poly(ethylene terephthalate) substrate, exhibits an uncompromised switching performance. The present study is the first attempt to explore the use of a recombinant protein as a functional switching layer in RS devices. This approach opens up a new method of harnessing recombinant proteins with engineered properties as powerful building blocks to suit the requirements of next-generation biocompatible, flexible, high-performance, and low power consumption electronics.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2018/cmatex.2018.30.issue-3/acs.chemmater.7b04261/production/images/medium/cm-2017-04261p_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm7b04261'>ACS Electronic Supporting Info</A></P>

원자현미경을 이용한 생물시료의 생물리학적 분석기법 개발과 소개

조상준(Sang-Joon Cho),전기평(Kipyoung Jeon),최수경(Sookyung Choi) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

In order to develop fundamental nature-inspired technologies for future, various fields of science and technology have been invested to understand the complex biological system. Among the vast array of technologies, nanotechnological devices like the Scanning Probe Microscope (SPM) start to open new chapter of understanding structure, function, and regulation of this complex biological system at the nanometer level in real time with a hope for new scientific discovery. SPM provides not only high-resolution imaging of cellular structures below the optical limit, but also evaluation of biophysical properties of the biological samples and monitoring dynamics and processes even in real time. SPM technique promises direct access to the both structural and functional information of a biological sample at unprecedented high spatial resolution that no other techniques are able to provide currently. We will introduce the general applications and new development of SPM in life science research.

교통 이력 자료를 위한 대용량 데이터베이스 구축

송수경 ( Sookyung Song ),정수정 ( Sujeong Cheong ),이민수 ( Minsoo Lee ),남궁성 ( Sung Namgung ) 한국정보처리학회 2007 한국정보처리학회 학술대회논문집 Vol.14 No.2

현재 한국도로공사에서 운영하는 고속도로 교통관리시스템(FTMS)과 우회도로 교통정보시스템(ARTIS)은 차량 검지 장치와 CCTV 를 통해 실시간 교통 자료를 수집하고, 도로전광표지(VMS), 방송, 인터넷 등 다양한 매체로 교통 정보를 제공하는 시스템이다. 이러한 시스템들은 매일 도로에서 수집되는 엄청난 양의 교통 자료를 실시간 교통 정보 제공하는데 목적을 두고 있어, 교통 자료를 가공하고 처리하여 분석을 수행하는 연구 환경을 제공하는데 어려움이 많다. 본 논문에서는 여러 시스템으로부터 대용량의 교통 자료를 가져와 하나의 통합 데이터베이스로 구축하고, 이를 통해 얻은 교통 이력 자료를 연구할 수 있는 환경을 제안한다.

교통 데이터에 대한 품질 평가 및 자료 처리 기법의 구현

정수정(Sujeong Cheong),송수경(Sookyung Song),이민수(Minsoo Lee),남궁성(Sung Namgung) 한국정보과학회 2007 한국정보과학회 학술발표논문집 Vol.34 No.2C

대용량의 자료가 생산됨에 따라 데이터를 효율적으로 저장, 관리, 이용할 수 있는 데이터웨어하우스의 역할이 중요하게 되었고, 그에 따라 자료 처리 기법의 개발은 필수 과제가 되었다. 품질 평가와 오류 판단, 결측 보정의 자료 처리 과정은 자료의 신뢰도를 판단하고 활용도를 높일 수 있는 과정으로 매우 중요하다. 본 논문에서는 우리나라의 실제 교통상황을 반영하고 평가 기준의 오차를 줄이면서 더욱 간단명료한 평가 계산식을 도입하여 효율적인 품질평가와 오류판단, 결측 보정의 자료 처리 기법을 제안한다. 또한 오류 판단 기준에 새로운 파라미터를 도입하여 교통 연구자의 요구 사항을 반영할 수 있게 하였다. 결측 보정 과정은 여러 기법을 연구하고 기존의 결측 보정 기법에 입력 변수를 추가하여 실제 대용량의 교통 자료에 적용하였다. 그리고 교통 자료가 저장되는 데이터베이스에 직접 접근하여 결측 보정과정을 수행하도록 PL/SQL로 구현하였으며, 이를 통해 교통 연구자에게 쉽고 다양한 방법으로 결측 보정을 수행하고 그 결과를 이용하여 다양한 교통 정보를 가공할 수 있는 환경을 제공하였다.

Development of Microsatellite Markers Using Next-Generation Sequencing and Genetic Characterization in Three Natural Monument Populations of Koelreuteria paniculata (Goldenrain Tree)

Jei-Wan Lee,Sang-Chul Kim,Sookyung Shin,Ji-Young Ahn,Min-Woo Lee 한국원예학회 2020 원예과학기술지 Vol.38 No.4

This study was conducted to develop microsatellite markers in Koelreuteria paniculata using next-generation sequencing. A total of 71,114,562 reads of 20x coverage for the K. paniculata genome were generated and assembled to 141,924 contigs of a minimum of 500 bp long. One hundred seventy-nine of the 79,633 contigs containing microsatellite regions were used for primer design. Fourteen primer sets were selected as polymorphic markers by applying them to three K. paniculata populations, designated as natural monuments in Korea. Somewhat low levels of genetic diversity were observed. The grand means of the number of alleles, observed heterozygosity, and expected heterozygosity were 2.7, 0.493, and 0.407, respectively. Analysis of molecular variance indicated a high level of genetic differentiation among populations. Distinct patterns of three populations were identified in the principal coordinate analysis and Bayesian structure analysis. The probability of identity of these markers was estimated to be quite low, suggesting that these markers have the robust potential power to distinguish genetically different individuals. K. paniculata has a high economic value as an ornamental tree, and a honey tree. The novel microsatellite markers developed in this study will be useful for future breeding programs and genetic studies aimed at developing conservation plans.