• 한국정밀공학회지
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• 제21권5호
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• pp.99-105
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• 2004

Internet provides the useful method to monitor the current states of the machine tool no matter where a personnel monitors it. In this paper, a monitoring method of the torque of the machine tool's spindle induction motor using interne is suggested. To estimate the torque accurately, spindle driving system of an CNC lathe is divide into two parts, induction motor part and mechanical part attached to the induction motor spindle. Magnetizing current is calculated from the measured 3 phase currents without speed sensor used to estimate the torque generated by an induction motor. In mechanical part of the system, some of the torque is used to overcome friction and remaining torque is used to overcome cutting force. An equation to estimate friction torque is drawn as a function of cutting torque and rotation speed. Graphical programming is used to implement the suggested algorithm. to monitor the torque of an induction motor in real time and to make the estimated torque monitored on client computers. Torque of the spindle induction motor is well monitored on the client computers in about 3% error range under various cutting conditions.

• 한국건설관리학회논문집
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• 제25권3호
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• pp.68-82
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• 2024

The planning stage of laser scanning is crucial for acquiring high-quality 3D source data. It involves assessing the target space's environment and formulating an effective measurement strategy. However, existing practices often overlook on-site conditions, with decisions on scanner deployment and scanning locations relying heavily on the operators' experience. This approach has resulted in frequent modifications to scanning locations and diminished 3D data quality. Previous research has explored the selection of optimal scanner locations and conducted preliminary reviews through simulation, but these methods have significant drawbacks. They fail to consider scanner inaccuracies, do not support the use of multiple scanners, rely on less accurate 2D drawings, and require specialized knowledge in 3D modeling and programming. This study introduces an optimization technique for laser scanning planning using 3D simulation to address these issues. By evaluating the accuracy of scan data from various laser scanners and their positioning for scanning a retaining wall structure in a small-scale building, this method aids in refining the laser scanning plan. It enhances the decision-making process for end-users by ensuring data quality and reducing the need for plan adjustments during the planning phase.

• 대한교통학회지
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• 제22권5호
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• pp.61-73
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• 2004

복잡한 대규모의 도로망에서 방대한 정보를 분석하여 실시간으로 최적 경로를 탐색해야 하는 경로 안내 시스템에서는 탐색 효율이 필수적이다. 리를 위하여 많은 연구들이 탐색 대상이 되는 노드와 링크의 수를 줄이려고 노력해왔다. 이 논문에서는 일부 영역만이 탐색으로 함수의 최적값을 찾는 단계별 세분화 방법(Coarse Grid Method)의 원리를 도로망에 응용한ㄴ다. 처음에는 간선 도로망, 다음에는 주요 도로망, 그 다음에는 세부 도로망 등으로 그 대상을 단계적으로 세분화함으로써 동시에 수많은 노드들간의 경로를 찾는 기존 방법에서의 탐색시간을 단축한다. 이 시스템을 우리나라 전국 규모의 충분히 세분화된 실제 도로망에 적용하여 시스템의 효율성, 실용성과 실시간 운영 가능성을 경로의 탐색 시간, 경로의 적합성 등에서 입증한다.

• International Journal of Computer Science & Network Security
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• 제22권4호
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• pp.261-273
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• 2022

Over the last decade, the scientific community has been actively developing technologies for automated software bug fixes called Automated Program Repair (APR). Several APR techniques have recently been proposed to effectively address multiple classroom programming errors. However, little attention has been paid to the advances in effective APR techniques for software bugs that are widely occurring during the software life cycle maintenance phase. To further enhance the concept of software testing and debugging, we recommend an optimized automated software repair approach based on hybrid technology (OAPR-HOML'1). The first contribution of the proposed OAPR-HOML'1 technique is to introduce an improved grasshopper optimization (IGO) algorithm for fault location identification in the given test projects. Then, we illustrate an opposition learning based artificial neural network (OL-ANN) technique to select AST node-level transformation schemas to create the sketches which provide automated program repair for those faulty projects. Finally, the OAPR-HOML'1 is evaluated using Defects4J benchmark and the performance is compared with the modern technologies number of bugs fixed, accuracy, precession, recall and F-measure.

• 콘크리트학회논문집
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• 제11권6호
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• pp.57-67
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• 1999

Optimization scheme is presented for the design of precast prestressed double-tee beams used as slabs in the parking or market structures. The objective considered is defined by a function that minimizes the hight of the double-tee beam, including the prefabricated element and the concrete topping poured in a second phase. The Sequential Quadratic Programming method is adopted to solve the problem. As an example 12 double-tee beams are designed with the design loads of the current design code of our country. The results from optimization process show that at least 29cm less in overall height than that designed by PCI design handbook. The section determined from the optimization process was refined for practical considerations. A MathCad 7.0 Pro Spreadsheet was prepared to verify all ACI requirements for flexure, shear and deflections. Flexural tests are performed on four full-scale 12.5m prototype models and show that all the specimens are fully comply the flexural strength requirements as specified by ACI 318-95. The present optimization scheme can be used for wider application of the design of precast prestressed double-tee beams with different materials and configurations particularly for in a large scale or for important designs.

• 컴퓨터교육학회논문지
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• 제3권1호
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• pp.1-12
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• 2000

최근 리눅스 운영체제가 웹 서버용으로 많이 사용되고 있으나, 웹 서버를 구축하기 위한 여러 가지 소프트웨어의 설치 및 데이터베이스 연동 등의 번거로운 작업들이 필요하다. 특히 국내 초, 중, 고교에서는 학교의 여건상 컴퓨터를 전문적으로 활용하여 웹 서버 구축이나 사이버스쿨을 구축 할 인원도 흔하지 않다. 본 논문은 리눅스 상에서 웹서버 프로그램의 설치와 데이터베이스의 연동 및 웹 프로그래밍 언어를 이용하여 웹 기반 사이버 스쿨을 자동으로 구축해 주는 시스템의 설계 및 구현에 관한 것이다. 이 시스템의 설계 개념은 컨텐츠가 없는 웹 기반 사이버 스쿨의 생성과 컨텐츠의 구축 과정을 분리한 2단계(phase) 구축방법이다. 즉, 몇 개의 명령어로 웹 기반 사이버 스쿨을 구축하고, 컨텐츠는 적재기능(upload)을 이용하여 이미 만들어진 파일을 간단히 적재한다.

• 대한전기학회논문지:전력기술부문A
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• 제55권7호
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• pp.297-305
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• 2006

This paper summarizes a development of visualization software for protective engineering in low-voltage power systems. The study is concentrated on the following aspects. First, a software engineering method is applied for designing the object-oriented program. The design and implementation of a Graphic User Interface(GUI) and its integration to a power system framework are developed using object-oriented programming(OOP) in Visual C++. Second, we develop the short circuit analysis module that oriented a low-voltage power system. It is possible to calculate a peak, symmetrical RMS, DC component and asymmetrical fault currents for each time. And it is the first software that can calculate the fault current for single branch of three-phase system. The calculation accuracy is compared with commercial software, and the libraries of low-voltage components are served for convenience use. Third, protective engineering functions are equipped. It is possible to automatically select the circuit breaker which based on the user input characteristics and the fault current calculation and examine the protective coordination. Through the case study, we verified that the developed software can be effectively used to examine the protective engineering in low-voltage power systems.

• 대한교통학회지
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• 제17권2호
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• pp.127-135
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• 1999

간선도로상에서의 교통혼잡해소를 위해서 연동화기법이 많이 사용되지만 기존 모형들은 간선도로를 한 개의 교통축으로 하여 신호를 최적화해주기 때문에 이들과 교차되는 교차도로는 물론 일반적인 도로망체계에서의 교통흐름을 고려하지 못한다. 그리고 도로망 제어가 가능한 모형의 경우에도 루프로 형성되어야 하고 현시순서에 제약이 따르기 때문에 적용상에 한계가 있다. 따라서 본 연구에서는 이러한 문제들을 해결하고자 이동류들을 이용하여 현시순서를 최적화하고 이를 일반적인 도로망에 적용할 수 있는 모형을 제시하였다. 모형적용 결과 본 모형은 다양한 도로망 구조나 교차로 형태를 반영하여 도로망에서의 차량흐름을 동시에 제어해주는 신호계획를 산정해 낼 수 있었다. 본 모형의 사용으로 일반적인 도로망체계에서 각 도로들의 교통량과 용량을 고려하는 연동처리가 가능해져 도시가로망에서의 교통흐름을 원활히 해줄 것으로 기대된다.

• 제어로봇시스템학회논문지
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• 제8권7호
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• pp.613-623
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• 2002

Ascent trajectory optimization and explicit guidance problems for a satellite launch vehicle with yaw maneuver in a 3-dimension are considered. The trajectory optimization problem with boundary conditions is formulated as a nonlinear programming problem by parameterizing the inertial pitch and yaw attitude control variables, and is solved by using the SQP algorithm. The flight constraints such as gravity-turn and range safety conditions are imposed. An explicit inertial guidance algorithm in the exoatmospheric phase is also presented. The guidance algorithm provides steering command and time-to-go value directly using the current states of the vehicle and the desired orbit insertion conditions. The liquid propelled Delta 2910 launch vehicle is used as a numerical model.

• 한국산업정보학회논문지
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• 제15권5호
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• pp.149-158
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• 2010

본 논문에서는 Use Case Diagram, Class Diagram, Activity Diagram, Sequence Diagram을 이용하여 PDA용 메신저 프로그램을 설계 및 구현하였다. PDA용 메신저 프로그램 대상으로는 PC 서버기능, 로그인기능, 친구 관리기능, 쪽지기능, 대화가능, 파일전송가능, 회원메뉴기능 등 총 7가지 기능을 선정하였다. 본 논문의 구현 결과 다음과 같은 효과를 가져왔다. 첫째, UML Diagram을 이용함으로서 개발자가 개발할 문제와 프로그래밍의 흐름을 쉽게 이해 할 수 있었다. 둘째, PDA를 자주 이용하는 사용자들은 시간의 제약을 받지 않고, 오랜 시간 동안 개발자와 커뮤니케이션을 할 수 있었다. 셋째, 객체지향 분석 단계에서는 UML Diagram의 유용성이 높았다. 넷째, 프로그램의 Update와 Maintenance가 용이하였다.