• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.464-471
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• 2009

Robot and application of IT skill of construction industry are slow comparatively than another thing industry by the feature. This research proposes progress management and real time information gathering through construction automation and RFID focused on steel structure construction. Building for RTPM system, must consider various variables and surrounding situation in construction field and it is the most important and difficult matter that draw right requirement and grasp relation between this requirements to accomplish one suitable task considering these environment. Therefore, in this study analyzes requirement and target for RTPM system based on scenario that is easy to draw requirement and apply this to use case model. Presented method suggests that represent relation between goals and way that refines goal systematically from requirement of RTPM system. And it could express for visualization through the Way that attaches nonfunctional elements of system with system internal goal.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.368-368
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• 2022

The Soil and Water Assessment Tool (SWAT) has been widely used to simulate the long-term hydrological conditions of a catchment. Two output variables, outflow and sediment yield have been widely investigated in the field of water resources management, especially in determining the conditions of ungauged subbasins. The presence of missing data in weather input data can cause poor representation of the climate conditions in a catchment especially for large or mountainous catchments. Therefore, in this study, a custom module was developed and evaluated to determine the efficiency of utilizing basic spatial interpolation methods in the estimation of weather input data. The module has been written in Python language and can be considered as a pre-processing module prior to using the SWAT model. The results of this study suggests that the utilization of the proposed pre-processing module can improve the simulation results for both outflow and sediment yield in a catchment, even in the presence of missing data.

• 지구물리와물리탐사
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• 제5권4호
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• pp.280-290
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• 2002

유한요소법을 이용한 전자기장의 3차원 모델링은 전자기장의 연속조건을 수치해가 만족하지 못함으로 인해서 발생하는 벡터 기생해(vector parasite)의 문제점을 가지고 있다. 이 연구에서는 벡터 기생해로 인한 오차를 줄이기 위해, 기저함수가 크기와 방향을 가지는 벡터요소를 도입하였다. 유한요소 행렬식은 complex BCG법을 적용하여 계산시간과 기억용량을 줄이고자 하였으며, 반복적인 해의 수렴속도 향상을 위해서 Point Jacobi법을 적용하였다. 개발된 알고리듬을 수직 전기 쌍극자 송신원을 이용한 층서구조 모형에 적용하여 이를 층서구조의 해와 비교함으로써 수치 모델링 알고리듬의 타당성을 검증하였으며, 이 과정에서 기존의 유한요소법에서 발생하는 벡터 기생해의 문제점이 벡터요소를 이용하는 경우에는 나타나지 않는 것을 확인하였다. 개발된 3차원 전자탐사 모델링 기법의 고주파수 영역으로의 적용성을 고찰하기 위하여, 100MHz의 수직 자기 쌍극자 송신원을 이용한 모델링을 유전율 이상층이 존재하는 층서구조 모형에 적용하여, 이를 층서구조 해와 비교하여 알고리듬의 타당성을 확인하였다. 검증된 3차원 전자탐사 모델링 기법을 유전율 이상체에 적용하여 이상체 주변에서의 전기장의 반응을 공간적으로 살펴보았다 이 연구에서 개발된 벡터요소를 사용한 3차원 고주파 전자탐사 모델링 기법은 기존의 전기전도도 이상체 뿐만 아니라 유전율 이상체에 대한 모델링을 가능하게 하여, 고주파 전자탐사법의 새로운 적용 및 해석의 기반을 제공할 수 있을 것으로 기대된다.

• 유통과학연구
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• 제17권3호
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• pp.107-116
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• 2019

Purpose - Why, why is it difficult to predict the appropriateness of self-employment, and what are the countermeasures and policy proposals to overcome. This study intends to further develop the field of statistical variables. It is necessary to overcome the limitation of existing proper scale research in Korea. We need to find statistical variables that can determine the appropriateness of self-employment in Korea. These efforts will be helpful in evaluating OECD countries and statistics and developing domestic economic indicators. Research design, data, and methodology - It is the discovery of statistical indicators and complementary indicators that have not been revealed in previous studies. Therefore, we sought to find new statistical parameters based on the statistics of the Korea National Statistical Office, the Bank of Korea, and overseas OECD statistics. (Proper Size of Adequacy) is defined as the specific gravity or number of the self-employed in Korea, which is shown as "Out Put" by statistical analysis of STATA panel statistical data. It is possible to further develop variables such as gross domestic product, gross national product, economic growth rate, unemployment rate, income tax rate, consumer price, tax level, exports, import amount, bill default I want to dig. Results - In addition to expanding economic indicators that can be explained by self-employment determinants, we have developed a variety of methods such as linear and non-linear (U-shaped, inverted U-shaped). It is the improvement of the self-employment determinants and the analysis method to estimate the appropriate scale. Conclusions - The proposed contents are reflected in self - employment appropriateness evaluation data and hope to help the government to select the policy support and to evaluate the government business after the policy support. These efforts are expected to be of great help to operators operating their own businesses, and to government and related institutional practitioners who support them. In this way, self-employment will be created in accordance with the Korean situation, where the happy life of all the people becomes the premise and the inclusive economic activities are guaranteed. It will improve the method of analyzing proper scale of small business owners and self-employed in Korea.

• 한국추진공학회지
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• 제3권2호
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• pp.1-9
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• 1999

층류 유동을 기준으로 형성된 압력구배기법의 적용성을 난류유동에 대하여 검증하였다. 압력구배기법은 압력 자체보다는 연속방정식을 이용하여 구한 압력의 구배를 활용하므로서 유동장의 해석에 질량보존의 물리적 법칙을 용이하게 반영할 수 있는 특징이 있다. 압력구배기법은 모든 유동변수를 한 점에 위치시키고 압력구배는 그 사이에 위치시키는 준 엇갈림 좌표계를 기준으로 형성되었다. 이러한 격자계는 프로그램하기가 용이하며 유동의 물리적 특성을 올바로 반영할 수 있는 장점이 있다. 난류유동에 대한 검증은 저 레이놀즈수 $\kappa$-$\varepsilon$ 모델을 이용하여 완전히 발달한 채널유동, 후향계단유동, 원추형 디퓨저유동 등에 대하여 수행하였다. 이러한 해석결과로부터 압력구배기법은 난류유동의 해석에 적용이 가능한 것으로 판단된다. 그러나 압력구배기법은 계산시간이 다소 길게 요구되며 압력구배식의 적정 $\gamma$를 구하는 방법이 용이하지 않아 이에 대한 개선이 요구되고 있다.

• 한국토양비료학회지
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• 제12권1호
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• pp.15-23
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• 1979

본(本) 연구의 제(第)1보(報)에서 추출(抽出)된 비옥도(肥沃度) 구성인자(構成因子)의 인자평점(因子評点) 및 현지조사(現地調査)에서 얻은 기타(其他) 환경인자(環境因子)를, 설명변수(說明變數)로 취(取)하고, 현지(現地)에서 청취조사(聽取調査)로부터 얻어진 쌀 수확량(收穫量)을 목적변수(目的變數)로 하여 다중회귀(多重回歸) 분석(分析)과 하야시의 수량화(數量化) 이론(理論) I (Hayashi's theory of quantification No.1)를 적용(適用)하여 생산력을 추정(推定)한 결과(結果)는 다음과 같다. (1) 시료(試料) 개체(個體)에 대하여 얻어진 다섯개의 인자평점(因子評点)을 설명변수(說明變數)로 하여 다중회귀분석(多重回歸分析)을 행(行)한 결과(結果) 중상관계수(重相關係數)가 0.43으로 추정(推定) 정도(程度)가 낮았다. (2) 비옥도(肥沃度) 인자간(因子間)의 상호작용(相互作用)을 고려(考慮)하여 직선회귀(直線回歸) 모델을 이차방정식(二次方程式)으로 변형(變形)시켜 생산력(生産力)을 추정(推定)한 결과(結果) 중상관계수(重相關係數)가 0.59로써 추정정도(推定精度)는 약간 높아졌으나 만족할 수 있는 추정식(推定式)은 얻지 못하였다. (3) 답(畓) 토양(土壤)에서 쌀의 생산력(生産力)을 지배(支配)하는 인자(因子)로서 비옥도(肥沃度)는 물론(勿論) 중요(重要)하지만 다른 환경인자(環境因子)의 영향(影響)도 받을 것으로 사료(思料)되어 비옥도군(肥沃度群), 수분공급(水分供給)의 양부(良否), 토양배수(土壤排水)의 양부(良否), 기후대(氣候帶), 표토(表土)의 점착성(粘着性), 표토(表士)의 결시성(結持性), 토성(土性) 및 하층토(下層土)의 구조발달정도(構造發達程度) 등(等)을 설명변수(說明變數)도 취(取)하여 하야시의 수량화(數量化) 이론(理論) 1을 적용(適用)하여 생산력(生産力)을 추정(推定)한 결과(結果) 중상관계수(重相關係數)가 0.9였고, 이들 인자(因子)들 중(中) 비옥도군(肥沃度群), 수분공급(水分供給) 및 기후대(氣候帶) 인자(因子)가 생산력(生産力)에 크게 기여(寄與)하고 있는 것으로 나타났다.

• 한국자기학회지
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• 제6권2호
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• pp.106-111
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• 1996

전동기와 같이 가동부를 갖는 전기기기는 힘이나 토크를 발생시키기 위하여 고안되었고, 힘이나 토크는 이들 기기의 해석과 설계에 중요한 요소이다. 지금까지 유한요소법을 이용한 전자력 계산 방법으로는 여러가지 방법들이 제시되어 왔고, 그 중 널리 사용되는 방법으로는 맥스웰 응력법과 가상변위법이 있다. 맥스웰 응력법은 맥스웰 스트레스텐서를 이용하여 표면 전자력 밀도를 구하고 이의 표면 적분으로 전자력을 구하는 방법이고, 가상변위법은 물체에 변위가 일어났을 때 발생하는 에너지의 변화량을 이용하여 전자력을 구하는 방법이다. 전류원이 포함된 문제에서는 정확도를 높이기 위하여 벡터포텐셜을 주로 이용하여 자장해석을 하여 왔으므로 본 논문에서는 유한요소법으로 3차원 자장 문제를 해석한 결과인 자기벡터포텐셜을 맥스웰 응력법과 가상변위법에 적용하여 전기기계의 각 요소의 전자력을 구하는 방법을 제시한다. 제시한 방법의 검증을 위하여 해석 모델을 솔레노이드로 하여 제시한 방법으로 구한 전자력을 3차원으로 해석한 결과와 비교하여 그 유용성을 증명한다.

• Asia pacific journal of information systems
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• 제4권2호
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• pp.247-263
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• 1994

This paper reports the results of a field study investigating the effect of user participation and attitude on the success of information system implementation during the system development process. The theoretical framework for this research is based on the organizational change theory, in which the attitude affects the effects of user's participation. User participation and attitude were defined as independent variables and the performance of system implementation as dependent variable. User participation was defined as a direct participation by end users in the process of the new information system development. This was measured by user's participation/non-participation. User attitude refers to user's opinions or feelings before a new system is developed. This was measured by user's favor toward a system. The performance of system implementation was measured by the surrogate variable, the degree of individual satisfaction on developed system. To achieve the objective of this research, a field research method utilizing questionnaires were employed. They were distributed to 221 users present during and/or after system development. Among 185 questionnaires returned, 175 questionnaires were used for analysis. The major findings can be summarized as follows: First, there was no significant effect of user participation on user satisfaction. Second, there was a significant effect of user attitude on user satisfaction. Third, there was no significant interaction effect of user participation and attitude on user satisfaction. It is worth to note that the user's participation did not have any significant effect on the user's satisfaction. It seems the reason for the above result is due to user's involuntary participation. In fact, the user does not have much leverage in the process of system development, which may result in poor performance of user participation. Since user attitude is an important factor in the success of system implementation, however, a method to overcome unfavorable attitude of user should proceed all others.

• 센서학회지
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• 제10권5호
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• pp.329-336
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• 2001

This paper describes the steering control and geomagnetism cancellation for an autonomous vehicle using an MR sensor. The magneto-resistive (MR) sensor obtains the vector summation of the magnetic fields from embedded magnets and the Earth. The vehicle is controlled by the magnetic fields from embedded magnets. So, geomagnetism is the disturbance in the steering control system. In this paper, we propose a new method of the sensor arrangement in order to remove the geomagnetism and vehicle body interference. The proposed method uses two MR sensors located in a level plane and the steering controller has been developed. The controller has three input variables ($dB_x$, $dB_y$, $dB_z$) using the measured magnetic field difference, and an output variable (the steering angle). A simulation program was developed to acquire the data to teach the neural network, in order to test the ability of a neural network to learn the steering control process. Also, the computer simulation of the vehicle (including vehicle dynamics and steering) was used to verify the steering performance of the vehicle controller using the neural network. From the simulation and field test, good result was obtained and we confirmed the robustness of the neural network controller in a real autonomous vehicle.

• Steel and Composite Structures
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• 제48권2호
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• pp.113-130
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• 2023

The present manuscript aims to investigate the deviation between the middle surface (MS) and neutral surface (NS) formulations on the static response of bi-directionally functionally graded (BDFG) porous plate. The higher order shear deformation plate theory with a four variable is exploited to define the displacement field of BDFG plate. The displacement field variables based on both NS and on MS are presented in detail. These relations tend to get and derive a new set of boundary conditions (BCs). The porosity distribution is portrayed by cosine function including three different configurations, center, bottom, and top distributions. The elastic foundation including shear and normal stiffnesses by Winkler-Pasternak model is included. The equilibrium equations based on MS and NS are derived by using Hamilton's principles and expressed by variable coefficient partial differential equations. The numerical differential quadrature method (DQM) is adopted to solve the derived partial differential equations with variable coefficient. Rigidities coefficients and stress resultants for both MS and NS formulations are derived. The mathematical formulation is proved with previous published work. Additional numerical and parametric results are developed to present the influences of modified boundary conditions, NS and MS formulations, gradation parameters, elastic foundations coefficients, porosity type and porosity coefficient on the static response of BDFG porous plate. The following model can be used in design and analysis of BDFG structure used in aerospace, vehicle, dental, bio-structure, civil and nuclear structures.