• 한국과학교육학회지
• /
• 제13권1호
• /
• pp.31-47
• /
• 1993

This study was intended to find the characteristics of the middle school students' thinking processes and problem spaces when they solved the physics problems. Ten ninth grade students in Chon-Buk Do, Korea were participated in this study. The researcher investigated their thinking processes in solving 5 physics problems on electric circuit. "Thinking aloud" method was used as a research method. The students' thinking processes were recorded using an audio tape recorder and transfered into protocols. The protocols were analyzed by problem solving process coding system which was developed by Lee(1987) on the basis of Larkin's problem solving process model. The results are as follows : (1) On the average 2.85 items were solved among 5 test items, and only one person could solve all of the items correctly. (2) Problems were solved in sequence of understanding the problem, planning, carrying out the plan, and evaluating steps regardless of the problem difficulty. (3) In regard to the thinking process steps, there was no difference between the good solvers and the poor ones. But in the detail performance of problem solving, the former was different from the latter in respect with using the design of general solving procedure. (4) The basic problem spaces by the item analysis were divided into two classes. One was the problem space by using Qualitative approach in problem solving, and the other was one by using Quantitative approach. As novices in physics problem solving, most of the students used the problem space by using the Quantitative approach.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권11호
• /
• pp.1491-1495
• /
• 2004

Small Tail Han Sheep has significant characteristics of high prolificacy and non-seasonal ovulatory activity and is an excellent local sheep breed in P. R. China. Recently a novel member of the transforming growth factor $\beta$ (TGF$\beta$) superfamily termed bone morphogenetic protein 15 (BMP15) was shown to be specifically expressed in oocytes and to be essential for female fertility. Therefore, BMP15 is a candidate gene for reproductive performance of Small Tail Han Sheep. The whole genomic nucleotide sequence of BMP15 gene in Small Tail Han Sheep was searched for polymorphisms by PCR-SSCP and direct sequencing, and only one polymorphism was found. The polymorphism was a result of a 3 base pair deletion, which eliminated a single Leu codon (CTT). The allelic frequencies for A (without deletion) and B (with a codon deletion) are 0.73 and 0.27 respectively. The effects of BMP15 genotype on litter size were evaluated using the least squares model. This indicated that there was a significant association between litter size of Small Tail Han Sheep and a deletion in BMP15 gene (p=0.02<0.05). Small Tail Han Sheep ewes with AA and AB genotype produce on average 0.5 and 0.3 more lambs per litter than those ewes with BB genotype.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권20호
• /
• pp.8741-8747
• /
• 2014

Purpose: We aimed to investigate the associations between polymorphisms of interleukin-1A (IL-1A), IL-1B, and IL-1 receptor antagonist (IL-1RN) and prostate cancer (PCa) risk. Materials and Methods: A comprehensive search for articles of MEDLINE and EMBASE databases and bibliographies of retrieved articles published up to August 3, 2014 was performed. Methodological quality assessment of the trials was based on a standard quality scoring system. The meta-analysis was performed using STATA 12.0. Results: We included 9 studies (1 study for IL-1A, 5 studies for IL-1B, and 3 studies for IL-1RN), and significant association was found between polymorphisms of IL-1B-511 (rs16944) as well as IL-1B-31 (rs1143627) and PCa risk. IL-1B-511 (rs16944) polymorphism was significantly associated with PCa risk in homozygote and recessive models, as well as allele contrast (TT vs CC: OR, 0.74; 95%CI, 0.58-0.94; P=0.012; TT vs TC+CC; OR, 0.79; 95%CI, 0.63-0.98; P=0.033; T vs C: OR, 0.86; 95%CI, 0.77-0.96; P=0.008). The association between IL-1B-31 (rs1143627) polymorphism and PCa risk was weakly significant under a heterozygote model (OR, 1.35; 95%CI, 1.00-1.80; P=0.047). Conclusions: Sequence variants in IL-1B-511 (rs16944) and IL-1B-31 (rs1143627) are significantly associated with PCa risk, which provides additional novel evidence that proinflammatory cytokines and inflammation play an important role in the etiology of PCa.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
• /
• pp.28.4-29
• /
• 2009

The 'Amon-Ra' instrument of the proposed 'EARTHSHINE' satellite is a dual (i.e. imaging and energy) channel instrument for monitoring the total solar irradiance (TSI) and the Earth's irradiance at around the L1 halo orbit. Earlier studies for this instrument include, but not limited to, design and construction of breadboard Amon-Ra imaging channel, stray light suppression and system performance computation using Integrated Ray Tracing (IRT) technique. The Amon-Ra instrument is required to produce 0.3% in uncertainty for both Sunlight and Earthlight measurement. In this study, we report accurate estimation of the output electric signal derived from the orbital variation of radiant exitance from the Sun and the Earth arriving at the aperture and detector plane of the Amon-Ra. For this, orbital irradiance are computed analytically first and then confirmed by simulation using Integrated Ray Tracing (IRT) model. Specially, the results show the arriving power at the bolometer detector surface is $1.24{\mu}W$ for the Sunlight and $1.28{\mu}W$ for the Earthlight, producing the output signal pulses of 34.31 mV and 35.47 mV respectively. These results demonstrate successfully that the arriving radiative power is well within the bolometer detector dynamic range and, therefore, the proposed detector can be used for the in-orbit measurement sequence. We discuss the computational details and implications as well as the simulation results.

• Journal of Microbiology and Biotechnology
• /
• 제22권6호
• /
• pp.818-825
• /
• 2012

Keratinases are exciting keratin-degrading enzymes; however, there have been relatively few studies on their immobilization. A keratinolytic protease from Chryseobacterium sp. kr6 was purified and its partial sequence determined using mass spectrometry. No significant homology to other microbial peptides in the NCBI database was observed. Certain parameters for immobilization of the purified keratinase on chitosan beads were investigated. The production of the chitosan beads was optimized using factorial design and surface response techniques. The optimum chitosan bead production for protease immobilization was a 20 g/l chitosan solution in acetic acid [1.5% (v/v)], glutaraldehyde ranging from 34 g to 56 g/l, and an activation time between 6 and 10 h. Under these conditions, above 80% of the enzyme was immobilized on the support. The behavior of the keratinase loading on the chitosan beads surface was well described using the Langmuir model. The maximum capacity of the support ($q_m$) and dissociation constant ($K_d$) were estimated as 58.8 U/g and 0.245 U/ml, respectively. The thermal stability of the immobilized enzyme was also improved around 2-fold, when compared with that of the free enzyme, after 30 min at $65^{\circ}C$. In addition, the activity of the immobilized enzyme remained at 63.4% after it was reused five times. Thus, the immobilized enzyme exhibited an improved thermal stability and remained active after several uses.

• Genomics & Informatics
• /
• 제7권1호
• /
• pp.38-40
• /
• 2009

The EST Knowledge Integrated System, EKIS (http://ekis.kribb.re.kr), was established as a part of Korea's Ministry of Education, Science and Technology initiative for genome sequencing and application research of the biological model organisms (GEAR) project. The goals of the EKIS are to collect EST information from GEAR projects and make an integrated database to provide transcriptomic and metabolomic information for biological scientists. The EKIS constitutes five independent categories and several retrieval systems in each category for incorporating massive EST data from high-throughput sequencing of 65 different species. Through the EKIS database, scientists can freely access information including BLAST functional annotation as well as Genechip and pathway information for KEGG. By integrating complex data into a framework of existing EST knowledge information, the EKIS provides new insights into specialized metabolic pathway information for an applied industrial material.

• 한국통신학회논문지
• /
• 제41권9호
• /
• pp.1120-1131
• /
• 2016

본 논문은 흡연으로 인한 화재사고 방지를 위해, 비디오 영상에서 흡연자를 검출하는 알고리즘을 제안한다. 흡연자의 행동을 인식하기 위해 행동 인식 기법의 계층적 방법 중 서술 기반 접근 방법을 기반으로 제안하는 알고리즘은 배경 영역 분리, 객체 검출, 이벤트 탐지, 이벤트 판단 과정으로 구성된다. 배경 영역 분리 과정으로 학습률이 다른 두 개의 가우시안 혼합 모델을 이용하여 입력 영상으로부터 고속 움직임 전경, 저속 움직임 전경 영상을 생성하고, 저속움직임 전경 영상을 chain-rule 기반 외곽선 검출 알고리즘을 통하여 객체의 위치를 추출해낸다. 위치 정보를 기반으로 흡연자의 세 가지 특징인 얼굴, 연기, 손의 움직임을 이벤트 탐지 과정에서 검출한다. Haar-like feature를 이용하여 얼굴을 검출하며, 고속 움직임 전경에서 연기의 발생 빈도수와 방향성을 반영하여 연기를 검출한다. 움직임 추정을 통해 반복적인 손의 움직임을 검출한다. 일정 구간의 비디오 시퀀스 내 객체들에 대하여, 검출된 특징들의 서술적 관계를 반영하여 각각의 객체가 흡연자인지 판단한다. 제안하는 방법은 실시간으로 여러 다른 객체들 사이에서 강인하게 흡연자를 검출한다.

• 분석과학
• /
• 제13권1호
• /
• pp.101-107
• /
• 2000

자동차 페인트는 안료층과 도색된 페인트층의 색상, 도막층의 배열 및 화학적 성분에 의해 구별되어 질 수 있다. 법과학 시료로 채택된 페인트 도막의 미세편에 의한 뺑소니 차량의 성공적인 확인은 표준시료의 포괄적인 수집 및 전처리 과정 없이 직접 분석하는 기법이 무엇보다 중요하다. 열분해 가스크로마토그래피는 고분자 시료뿐만 아니라 법과학적 시료의 정성 및 정량분석을 수행하는데 정확하고 신뢰성 있는 방법으로 널리 이용되고 있다. 본 실험실은 국내에서 선호도가 높은 각 자동차 회사의 4개 색상 73종에 대해 Curie Point Pyrolyzer(JHP-3) 및 Capillary Column(Ultra Alloy-5)이 장착된 가스크로마토그래프를 이용하여 실험을 진행하였다. 이 분석방법은 용의차량의 페인트와 유류된 페인트의 비교뿐만 아니라 자동차의 제조회사, 차종검객까지 확인하는 데에 이용이 가능하였다.

• Wind and Structures
• /
• 제28권5호
• /
• pp.285-298
• /
• 2019

For super long-span bridges, the aerodynamic forces induced by the flow passing the box girder should be considered carefully. And the Reynolds number sensitively of aerodynamic characteristics is one of considerable issue. In the study, a numerical study on the Reynolds number sensitivity of aerodynamic characteristic (flow pattern, pressure distribution and aerodynamic forces) of a twin-box girder were carried out using large eddy simulation (LES) with the dynamic Smagorinsky-Lilly subgrid model. The results show that the aerodynamic characteristics have strong correlation with the Reynolds number. At the leading edge, the flow experiences attachment, departure, and reattachment stages accompanying by the laminar transition into turbulence, causing pressure plateaus to form on the surface, and the pressure plateaus gradually shrinks. Around the gap, attributing that the flow experiences stages of laminar cavity flow, the wake with alternate shedding vortices, and turbulent cavity flow in sequence with an increase in the Reynolds number, the pressures around the gap vary greatly with the Reynold number. At the trailing edge, the pressure gradually recovers as the flow transits to turbulence (the flow undergoes wake instability, shear layer transition-reattachment station), In addition, at relative high Reynolds numbers, the drag force almost does not change, however, the lift force coefficient gradually decreases with an increase in Reynolds number.

• 한국정보통신학회논문지
• /
• 제25권2호
• /
• pp.308-313
• /
• 2021

이 연구는 2019년 판문점 남북미 정상 회동 트윗을 타임 시퀀스와 함께 수집하여 시퀀셜 토픽모델링인 DTM으로 분석하였다. 트위터와 같은 마이크로 블로깅 서비스는 단일 이벤트에 뉴스와 오피니언이 혼재된 비정형 데이터가 대규모로 동시에 발생하고, 정보와 반응이 동일 메시지 형식으로 생산된다. 때문에 토픽 트렌드를 파악하려면 시퀀셜 데이터의 특성을 반영하여 패턴 분석을 해야 맥락적 의미를 알 수 있다. 토픽 일관성 점수를 구해 LDA를 평가한 후 DTM을 계산한 결과, 뉴스 보도와 오피니언 관련 토픽 30개가 도출되었고, 각 토픽과 키워드는 시간에 따라 발생 확률이 역동적으로 진화하고 있었다. 결론적으로 DTM은 특정 이벤트에 대한 사회 전반에 나타난 통합적 토픽 추이를 시간에 따라 분석하는데 적합한 모델임을 밝혔다.