• 한국정보처리학회논문지
• /
• 제7권8호
• /
• pp.2310-2326
• /
• 2000

데이터전송(data-shipping)모델에 근간을 둔 클라이언트-서버(client-server)DBMS는 트랜잭션간 캐슁(inter-transaction caching)을 허용함에 의해 클라이언트의 자원을 효율적으로 이용할 수 있다. 그거나 트랜잭션간 캐슁을 허용하면 각 클라이언트는 데이터베이스의 일부분을 동적으로 캐슁할 수 있기 때문에 트랜잭션 캐쉬 일관성 유지(transactional cache consistency maintenance : TCCM)기법의 필요성을 야기한다. 지연 로킹(deferred locking: DL)기법은 주사본 로킹 기법에 근간을 둔 새로운 검사기반의 TCCM 기법이다. DL에서는 클라이언트에 캐슁된 데이터의 유효성 검사를 위한 메시지 부담을 줄이기 위하여 다수의 로크 요청과 데이터전송 요청을 단일 메시지로 구성하였다. 모의실험을 통하여, DL 기법과 검사기반기법중 가장 대표적인 적응적 낙관적 동시성 제어 기법과 캐슁 두단계 로킹 기법과의 성능을 비교하였다. DL 기법은 다른 검사기반 기법과 비교하여 적당한 수준의 트랜잭션 철회율을 보이며 성능도 우수하다.

• 경영과학
• /
• 제18권1호
• /
• pp.155-164
• /
• 2001

The widespread diffusion of Internet has enables every college and education institute to develope cyber education systems to meet the multiple needs of students, but it is not true that the effectiveness of cyber education is fruitful in terms of evaluation systems. Most of the early developed web-based evaluation systems for cyber education require that all the students should solve uniformed test set which are included in the predetermined static HTML pages. Therefore, it is impossible to dynamically provide a test set with consistency and reliability. This paper purpose to describe the employment of simulated annealing in cyber testbank system for test set generation that satisfy all constraints. The constraints include number of items for each skill, method, domain, topic, and so on. This research developed two phase heuristic combining sequential test set generation algorithm with simulated annealing. As a result of computer simulations, it was found that the two phase heuristic outperforms the other algorithms.

• Bulletin of the Korean Chemical Society
• /
• 제16권9호
• /
• pp.873-885
• /
• 1995

The local structural and thermodynamical properties of blends A-B/H of a diblock copolymer A-B and a homopolymer H are studied using the polymer reference interaction site model (RISM) integral equation theory with the mean-spherical approximation closure. The random phase approximation (RPA)-like static scattering function is derived and the interaction parameter is obtained to investigate the phase transition behaviors in A-B/H blends effectively. The dependences of the microscopic interaction parameter and the macrophase-microphase separation on temperature, molecular weight, block composition and segment size ratio of the diblock copolymer, density, and concentration of the added homopolymer, are investigated numerically within the framework of Gaussian chain statistics. The numerical calculations of site-site interchain pair correlation functions are performed to see the local structures for the model blends. The calculated phase diagrams for A-B/H blends from the polymer RISM theory are compared with results by the RPA model and transmission electron microscopy (TEM). Our extended formal version shows the different feature from RPA in the microscopic phase separation behavior, but shows the consistency with TEM qualitatively. Scaling relationships of scattering peak, interaction parameter, and temperature at the microphase separation are obtained for the molecular weight of diblock copolymer. They are compared with the recent data by small-angle neutron scattering measurements.

• 한국BIM학회 논문집
• /
• 제10권4호
• /
• pp.98-109
• /
• 2020

Based on the prior research which developed the consistency review checklist of the BIM model and 2D drawing through the drawing analysis of the construction documents phase, the apparent limits of the existing template and the template development items were derived. As well, the BIM-based drawing templates of the construction documentation phase were developed and verified using ArchiCAD BIM software. The developed template was then applied to the actual project model in the construction documents phase, and, as a result, 50% of existing work elements could be utilized as templates. This is an increase of more than 30% over the existing template utilization elements, and it is analyzed to be effective in practical application and utilization. Based on the results of this study, if the BIM model construction criteria matching the drawing's utilization purpose are presented, while at the same time the BIM data interlocking and drawing template development studies are conducted, the utilization of BIM data can be maximized and additional drawing work can be minimized to increase the percentage of template utilization elements. In addition, it is believed that this can employed to address functional and institutional problems of BIM-based drawing and make a contribution to the activation of BIM.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2000년도 가을 학술발표논문집 Vol.27 No.2 (1)
• /
• pp.513-515
• /
• 2000

시스템 개발 단계 중 분석 단계는 이후의 설계, 구현 및 유지 보수 단계를 지원하기 위한 가장 중요한 단계로, 이후 단계에 미치는 영향이 크다. 그러므로, 분석단계의 산출물이 정확한지, 산출물간의 일관성을 검증하는 작업이 필요하다. 이에, 본 논문에서는 비즈니스 업무 개발에 초점을 두어, 사용자의 참여가 이루어지는 단순한 표기법을 사용하는 정보구조 모델링의 분석 단계의 여러 구조도 들간의 일관성 검증 방법을 제시한다. 이로써 분석 단계 중에 범하기 쉬운 오류들을 최소화하여, 정확한 분석 모델을 통한 사용자 만족도가 높은 시스템을 만들 수 있다.

• Journal of Power Electronics
• /
• 제14권1호
• /
• pp.92-104
• /
• 2014

To insure stable operation and eliminate twice torque ripple, a topology for a six phase permanent magnet synchronous generator (SP-PMSG) with a neutral point connected together was analyzed in this paper. By adopting an extended transformation matrix, the mathematic model of the space vector control was established. The voltage and torque equations were deduced while considering the third harmonic flux and inductance. In addition, the suppression third harmonic method and the closed loop control strategy were proposed. A comparison analysis indicates that the cooper loss minimum method and the current magnitude minimum method can meet different application requirements. The voltage compensation amount for each of the methods was deduced which also takes into account the third harmonic effect. A simulation and experimental result comparison validates the consistency through theoretical derivation. It can be seen that all of the two control strategies can meet the requirements of post-fault.

• 한국미생물·생명공학회지
• /
• 제25권6호
• /
• pp.560-565
• /
• 1997

DNA fragment assembly is a major concem in shot-gun DNA sequencing project. It is to reconstruct a consensus DNA sequence from a collection of random oritented fragments. We developed a computer program that is useful for DNA fragment assembly. Inputs to the program are DNA fragment sequences including IUB-IUPAC bases. The program produces the most probable reconstruction ot the original DNA sequence as a text format or a PostScript format. The program consists of four phases: the first phase quickly eliminates fragment pairs that can not possibly overlap. In the second phase, the quality of overlap between each pair is calculated to a score. In the third phase, overlap pairs are sorted by their scores and consistency of the overlaps is checked. The last phase determines consensus sequences and displays them. The performance of fragment assembly program was tested on a set of DNA fragment sequences which were generated from long DNA sequences of GenBank by a fragmentation program.

• 대한인간공학회:학술대회논문집
• /
• 대한인간공학회 1996년도 춘계학술대회논문집
• /
• pp.301-306
• /
• 1996

Different patterns of dynamic trunk performance between normal subjects and low-back pain (LBP) patients have been investigated. Ten healthy subjects and ten LBP patients were recruited for this study. An experiment was designed to quantify the dynamic motion of the back and hip during repetitive flexion/extension of the trunk. The angular velocity, angular acceleration and the phase angle difference between the hip and back were recorded as dependent measures via electro- mechanical devices. Results showed the significant differences in the velocity and acceleration of the hip and back and the phase angle between normal subjects and LBP patients. The consistency of kinematic variables during motion cycles was also examined in terms of variance ratio (Hershler and Milner, 1978). Based on the results of the study, these quantifiable variables such as trunk kinematics and hip-spine coordination can be developed as a medical tool to identify LBP patients in addition to current imaging techniques.

• Korean Chemical Engineering Research
• /
• 제47권6호
• /
• pp.755-761
• /
• 2009

일반적으로 비등점의 차이가 큰 물질들은 그 물리적 성질의 차이로 인해 혼합물에서 비이상적인 상거동을 보이며, 이러한 혼합물의 상거동 특성을 이해하기 위해서는 정확한 실험적 데이터가 필요하다. 본 연구에서는 재순환 평형조가 포함된 기-액 상평형 장치를 사용하여 10, 30, 60 kPa에서 톨루엔과 크레졸 혼합물에 대한 정압 기-액 평형 실험을 행하였다. 측정한 기-액 평형 데이터는 NRTL과 UNIQUAC 모델식을 이용하여 잘 적합할 수 있었으며 Gibbs/Duhem 식에 근거한 열역학적 건전성 테스트를 수행하여 실험결과의 건전성을 확인하였다. 한편, 혼합물의 과잉몰부피를 측정하여 Redlich-Kister 다항식으로 나타내었다.

• 공업화학
• /
• 제21권3호
• /
• pp.295-300
• /
• 2010

1-propanol과 bromochloromethane 혼합물은 공비점의 형성이나 큰 휘발성 차이 때문에 실제 증류탑이나 흡수탑 등의 단위 공정에서 효율적이고 경제적인 운전이 쉽지 않다. 이처럼 비이상성이 큰 혼합물을 효과적으로 다루기 위해서는 혼합물에 대한 기-액 평형 등의 열역학적인 정보가 필수적이다. 본 연구에서는 재순환 기-액 평형장치를 이용하여 일정 압력 하에서 30 kPa에서 70 kPa까지 1-propanol과 bromochloromethane 혼합물의 기-액 평형을 측정하였으며 얻어진 실험 데이터를 UNIQUAC과 NRTL 모델식을 이용하여 상관하였고 과잉 Gibbs 에너지와 활동도 계수를 추산하였다. 또한 Gibbs/Duhem식에 근거한 열역학적 건전성 테스트를 수행하였고 진동 밀도계를 사용하여 이성분계의 과잉 몰부피를 측정하였으며 그 결과를 Redlich-Kister다항식으로 상관하였다.