• Journal of Korean Society of Transportation
• /
• v.18 no.2
• /
• pp.17-26
• /
• 2000

LOS(Level of Service), the qualitative measure describing operational condition of highway, must be evaluated as quantative index in terms of user service. So, This study is focused on developing the user cost function that user cost is measured in the variation of V/C, MOE(Measure of Effectiveness) of LOS in basic Section of highway. The user cost is calculated as the sum of accident cost, operation cost, travel time cost. The data is collected in the four basic section of Singal-Ansan and Jung bu Highway. As the result of user cost function analysis, the user cost is the lowest When V/C is 0.54. Considering the V/C ratio(0.7) of Basic Section in rural highway suggested in KHCM, We find out that the LOS suggested KHCM increase the user cost of highway.

• Journal of Internet Computing and Services
• /
• v.5 no.5
• /
• pp.17-26
• /
• 2004

Mobile multicast schemes are classified into remote subscription and bi-directional tunneling. While the former scheme has much overhead in the maintenances of multicast tree, the latter suffers from inefficient routing. In this paper, we propose dynamic mobile multicast routing (DMMR) scheme, which is operated on the basis of cost functions related with forwarding cost and tree reconstruction cost, Basically DMMR intends to find lower cost between forwarding cost and tree reconstruction cost. Forwarding cost is the cost of tunneling multicast packets from home agent, and tree reconstruction cost is the joining cost of foreign agent to multicast group. In the case that a mobile host moves to the other area, its foreign agent calculates cost functions related with forwarding cost and tree reconstruction cost. If forwarding cost is higher than tree reconstruction cost, foreign agent joins to multicast group and reconstructs the multicast tree. Accordingly, foreign agent can dynamically adapt remote subscription or bi-directional tunneling, Our scheme provides more stable multicast service to the mobile hosts regardless of the movements of mobile host and the number of mobile group members.

• Journal of Korean Society of Transportation
• /
• v.22 no.7 s.78
• /
• pp.41-48
• /
• 2004

We may consider the inducement of demand to public transportation as a solution to relieve traffic congestion and pollution. Subway has merits as moving on schedule, transporting more people than bus. But subway is required a vast investment in the early stage of construction has a huge debt. So it runs into red figures, and on this account, services of subway are falling more and more. Development of subway's operation cost function is useful to understand structure of subway's operation and catch the relations of operation cost and actual results. In addition, we can present the policy that is a helpful to the operation as development of operation cost function. But there are short of studies about operation cost deal with a subway comparison with local train. Because local train has many lines and data, on the other hand, subway has one to four lines and less data. Most of previous studies sought the operation cost function of Seoul. So this study aimed to develop and apply the operation cost function of Seoul, Incheon, Busan and Daegu area using full allocation method. In this study, we considered the number of passengers, track-km, train-km, revenue as actual results. By appling the operation cost function, we compared the average cost of each city and confirmed the existence of economies of scale about the number of passengers, train-km.

• Journal of Digital Convergence
• /
• v.18 no.2
• /
• pp.261-268
• /
• 2020

Machine learning is achieved by making a cost function from a given digital signal data and optimizing the cost function. The cost function here has local minimums in the cost function depending on the amount of digital signal data and the structure of the neural network. These local minimums make a problem that prevents learning. Among the many ways of solving these methods, our proposed method is to change the learning step-size. Unlike existed methods using the learning rate (step-size) as a fixed constant, the use of multivariate function as the cost function prevent unnecessary machine learning and find the best way to the minimum value. Numerical experiments show that the results of the proposed method improve about 3%(88.8%→91.5%) performance using the proposed method rather than the existed methods.

• Journal of Convergence for Information Technology
• /
• v.11 no.3
• /
• pp.125-131
• /
• 2021

The problem of determining the maintenance point which minimizes the process-related total cost is called the 'process mean shift problem'. By expanding and integrating the existing maintenance models that have been partially progressed, we present a expanded and integrated maintenance model which reflects the production site where various situations occur. To implement this, we set both the upper and lower limits of the product specification, and adopted the quality loss function for conforming items. Also, we set the process variance of the wear level as a function rather than a constant. In this study, we developed two general functions to the wear level. One is about the production volume and the other is maintenance cost. As a result, this study is expected to be a maintenance model that can be applied to various processes. In the future, this study can be developed as a profit maximization model by adding profit items from product sales, and expansion to a maintenance model that introduces failure to the model of this study can be considered.

• Journal of the Korean Society for Railway
• /
• v.16 no.4
• /
• pp.318-330
• /
• 2013

It is necessary to estimate the operating cost for constructing an urban railway system. The present study was thus carried out to develop an estimation function of the operating cost for a MRT(Medium-sized Rapid Transit) system. We selected seven independent variables that could influence the operating cost: the rolling stocks, the number of trains in operation, the length of the lines, the number of stations, the number of passengers per day, the frequency of train operation, and the number of depots. We performed a multiple regression using Excel. Three types of regression functions were thereupon developed. All of them proved to be appropriate after comparing the results of the estimated cost. It will therefore be possible to use one of these three types, depending on the assumptions of the independent variables.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.43 no.10 s.352
• /
• pp.134-139
• /
• 2006

In this paper we present the Low-Power Bus Driven Floorplan(BDF) in which the bus power consumption is minimized by using a new cost function. The previously reported BDF has used the cost function which minimizes only the chid and the bus area. However, such a cost function may not consider the bus power consumption determined by the topology of a bus in case of the segmented bus design. In this paper, we formulate a new cost function which. reflects the communication frequency and the real distance between blocks in a bus to model the bus power consumption. For the Low-Power BDF with the new cost function, the experimental results show the bus power consumption cost is reduced by 11.43% on the average.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.3
• /
• pp.8-14
• /
• 2001

In this paper, we present a new cost function for subband block adaptive algorithm and block conjugate gradient algorithm for noise cancellation of acoustic signal. For the cost function, we process the subband signals with data blocks for each subbands and recombine it a whole data block. After these process, the cost function has a quadratic form in adaptive filter coefficients, it guarantees the convergence of the suggested block conjugate gradient algorithm. And the block conjugate gradient algorithm which minimizes the suggested cost function has better performance than the case of full-band block conjugate gradient algorithm, the computer simulation results of noise cancellation show the efficiency of the suggested algorithm.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1997.11a
• /
• pp.111-114
• /
• 1997

동영상 압축 알고리즘에서 움직임 추정기법은 매우 중요한 역할을 담당하는 반면, 수행시간이나 하드웨어 구현에 어려움이 많아 이를 개선하기 위한 알고리즘들이 개발되어 왔다. 본 논문에서는 적절한 화소 분류를 통해 우수한 화질과 적은 계산량, 간단한 하드웨어 구조를 가지는 새로운 움직임 추정기법을 제안한다. 기존의 1-비트 화소 분류 방법에서 변형된 새로운 비용 함수를 이용한 2-비트, 3-비트 화소 분류 방법과 2차 비용함수를 이용한 화소 분류 방법을 제안한다. 또한 여러 고속 움직임 추정 알고리즘과도 쉽게 연결하여 사용할 수 있으며 우수한 성능을 나타내는 것을 모의 실험을 통해 보였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.05c
• /
• pp.1647-1650
• /
• 2003

분산 데이터베이스 시스템에서 데이터의 할당이란 릴레이션이 분할되어 생성된 프래그먼트들을 여러 사이트에 분산시키는 것을 의미한다. 최적의 데이터 할당이란 할당에 소요되는 비용을 최소화시키는 할당 해를 찾는 것이라고 할 수 있는데, 본 논문에서는 저장, 질의 처리 및 전송 비용을 고려한 데이터 할당 함수를 정의하였다. 본 논문에서 정의한 할당 함수에서는 전송비용을 갱신 전송 비용과 검색 전송 비용으로 나누어서 산출하도록 정의하였다.