• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.574-577
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• 1995

The proposed method is described for scheduling their output of thermal power units so as to comply with total emission constraint, area emission constraint and the both of those constraints. Also, by using a trade-off curve, representing all dispatch alternatives and conflict between the emission and the fuel cost, the sensitivity analysis of the emission and the fuel cost is applied to this algorithm. By the way, this proposed method is analyzed how dispatch changes as a function of the total environmental cost, and as a function of the relative weighting of individual environmental insults, e.g, NOx and $SO_{2}$. By applying the proposed method to the system, the usefulness of this method is verified.

• ETRI Journal
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• 제40권1호
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• pp.101-110
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• 2018

In wireless positioning systems using range measurements non-line-of-sight (NLOS) links cause estimation errors. Several studies have attempted to improve the positioning performance by mitigating these NLOS errors. These studies, however, have focused on the performance of a dataset consisting of three or more links. Therefore, measurement errors induced by links are averaged, and a reliable link is not fully utilized in the dataset. This paper proposes a Link Reliability based on Range Measurement (LRRM) scheme, which specifies the relative reliability of each link using residuals. The link reliability becomes the input to a Link Residual Weighting (LRW) scheme, which is also proposed as a weighted positioning scheme. Moreover, LRRM and LRW constitute new turbo positioning, where the estimation errors are reduced considerably by iterative updates.

• 품질경영학회지
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• 제25권2호
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• pp.169-188
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• 1997

The purpose of this study is concerned with suggesting a new a, pp.oach to evaluating the overall product quality in the sense of the relative efficiency of products, whose quality is measured with 8-dimensional attributes, suggested by Garvin. The attributes included 8 quality measures, that is, performance, features, reliability, conformance, durability, serviceabilit, aesthetics, and perceived quality. This study, also, introduced DEA(Data Envelopment Analysis) as an evaluation tool to tackle the problem of how to measure one product against another when each product can be measured along a number of dimensions, and given that there exists no a priori satisfactory weighting scheme to combine these dimensions into an overall rating for each products. In order to a, pp.y the DEA to evaluating the products, we must define two concepts, such as DMU(Decision Making Units) and input-output relationship. Finally, the suggested method in this study was validated through a case study of the electric jar, and this DEA a, pp.oach can be used in evaluating the other products with multi-attrribute quality.

• Journal of Welding and Joining
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• 제16권3호
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• pp.44-54
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• 1998

In this study a new arc sensor algorithm for automatic weld seam tracking was proposed, which uses the relative welding current variation according to the tip-to-workpiece distance in GMA welding. Since the new developed arc sensor algorithm is not sensitive to unstable factors of arc signal, the system is expected to get rid of the problems of already existing arc sensor system which include the difficulty of modeling the process for various welding conditions and limitation of application to thick plate welding. Thus the system is applicable not only to thick plate welding but also to thin plate welding. To implement the new arc sensor algorithm the system parameters which include sampling time, averaging range, weighting factor of moving averaging, basic compensation time, and basic compensation distance were determined by experimental analysis. Consequently this system has shown the successful tracking capability for the various welding conditions.

• 한국정밀공학회지
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• 제15권11호
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• pp.100-107
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• 1998

This paper presents the development of estimation model and control method based on the new robot vision. This proposed control method is accomplished using the sequential estimation scheme that permits placement of the rigid body in each of the two-dimensional image planes of monitoring cameras. Estimation model with six parameters is developed based on the model that generalizes known 4-axis scara robot kinematics to accommodate unknown relative camera position and orientation, etc. Based on the estimated parameters, depending on each camera the joint angle of robot is estimated by the iteration method. The method is experimentally tested in two ways, the estimation model test and a three-dimensional rigid body placement task. Three results show that control scheme used is precise and robust. This feature can open the door to a range of application of multi-axis robot such as assembly and welding.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제19권3호
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• pp.289-303
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• 2015

In this paper, an optimal guidance law with terminal angle constraint considering the seeker's lock-on condition, in which the target is located within the field-of-view (FOV) and detection range limits at the end of the midcourse phase, is proposed. The optimal solution is obtained by solving an optimal control problem minimizing the energy cost function weighted by a power of range-to-go subject to the terminal constraints, which can shape the guidance commands and the missile trajectories adjusting guidance gains of the weighting function. The proposed guidance law can be applied to both of the midcourse and terminal phases by setting the desired relative range and look angle to the final interception conditions. The performance of the proposed guidance law is analyzed through nonlinear simulations for various engagement conditions.

• 대한한의학회지
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• 제18권1호
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• pp.456-469
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• 1997

The cerebral infarction arised from occulsion of cerebral artery has a high mortality rate and fatal sequelae. Sohabhyangwon(蘇合香元) is generally regarded to have a effect of walking up the patient from unconsiousness and promoting the flow of Qj(氣) by warming channel. METHOD The purpose of this study is to find out the effections of Sohabhyangwon(蘇合香元) on regional cerebral blood flow and relative cerebral infarction area in the experimentally induced infartion in rats In this experiment, 12 Spraque-Dawley rats weighting 280-350g were used. Cerebral ischemia induced by intraluminal suture technique of Kozumi's and Zea-Longer's method. $Co_{2},\;O_2$, pH, arterial blood pressure in rats were checked by Blood Gas Analyzer every 30 minutes for 2 hours. And regional cerebral blood flow were checking by hydrogen clearance technique, cerebral infarcted area was megsured by Image Analysis System. RESULTS 1. During the experiment, $CO_{2},\;O_2$, pH, arterial blood pressure in rats had no change in both sample group and control group. 2. Cortical cerebral blood flow decreased at same rate in both sample group and control group after inducing cerebral infarction. 3. On comparison of relative cerebral infarcted area, Sohabhyangwon(蘇合香元) perfused group showed a significant decrease. CONCLUSION According to the result above, Sohabhyangwon has a protection effect on cranial nerve and-has no effect on cerebral blood flow.

• 한국디지털건축인테리어학회논문집
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• 제13권1호
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• pp.33-41
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• 2013

Considering the fact that quality of life(QOL) conceptually has objective and subjective attributes but difficulties in measuring the subjective aspect cause a number of studies not to be balanced, this study exploits AHP(Analytical Hierarchy Process) which has been used for systematic decision making to include the other aspect. As the first step of the process decision making hierarchy model is set by content analysis of the UNDP QOL index and additional review of previous studies. 'Improving urban QOL' is a goal on top, 'Economical QOL', 'Environmental QOL', 'Social QOL' and 'Physical QOL' are dimensions of sub-goal(means objectives), and further decomposition follows. AHP shows that the dimensions of economical, physical, environmental and social QOL scored higher respectively. The aim of the model is to measure and prioritize the urban QOL in the two case study cities. The final score of the each city could be computed by integration of relative weights of dimensions for urban QOL. The final score of QOL for city A was 0.6642 and for city B the figure decreased to 0.3358. The method of this study could be used in stages of the process of urban planning. First stage is when planners try to have a correct and reliable perspective from the existed conditions of the city. Second stage is when the projects should be investigated to be confirmed for their efficiency. In other words planners can direct the scarce resources towards the aspects of QOL which are more important. And the results revealed that using AHP creates opportunity to involving the different groups in the stage of criteria weighting so that the attitudes of local community could be integrated well to the decision making to be suitable for a new paradigm of participatory and communicative planning.

• 한국지반신소재학회논문집
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• 제16권4호
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• pp.93-101
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• 2017

본 연구에서는 고소성 점토지반으로 구성된 광양지역의 준설매립층 및 원지반층에서 채취된 자연 시료를 이용하여 기존에 제안된 6가지 방법(Casagrande, Onitsuka, Silva, Becker, Janbu, Karlsrud)으로 선행압밀압력을 산정하는데 있어서 상대적인 용이성을 기준으로 5등급의 가중치 점수를 부여 하였다. 이 때, 높은 등급이 부여된다는 것이 곧바로 정확한 선행압밀압력의 산정을 의미하는 것은 아니므로, 불교란 시료에 의한 일축압축강도를 구한 후 압밀압력과의 상관관계를 나타내는 강도증가율을 평가하였다. 이를 토대로, 각각의 방법으로 평가된 선행압밀압력과 비배수전단강도의 비, 즉, 강도증가율이 국내 해성 점성토 지반의 일반적인 값의 범위인 0.25~0.35 사이의 분포 유무 및 표준편차(강도증가율의 변화폭)를 분석하여 적용성을 평가하였다. 그 결과, Becker 및 Onitsuka 방법의 평균 가중치가 다른 방법들(Casagrande, Janbu, Karlsrud)에 비해 낮고 강도증가율도 국내 해성점토 지반의 일반적인 값의 범위에 있으며, 표준편차도 낮게 평가되어 일관성 있는 평가가 가능한 것으로 분석되었다.

• Structural Engineering and Mechanics
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• 제65권2호
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• pp.173-181
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• 2018

In this paper, finite element (FE) model updating based on multi-objective optimization with the surrogate model for a steel plate girder bridge is investigated. Conventionally, FE model updating for bridge structures uses single-objective optimization with finite element analysis (FEA). In the case of the conventional method, computational burden occurs considerably because a lot of iteration are performed during the updating process. This issue can be addressed by replacing FEA with the surrogate model. The other problem is that the updating result from single-objective optimization depends on the condition of the weighting factors. Previous studies have used the trial-and-error strategy, genetic algorithm, or user's preference to obtain the most preferred model; but it needs considerable computation cost. In this study, the FE model updating method consisting of the surrogate model and multi-objective optimization, which can construct the Pareto-optimal front through a single run without considering the weighting factors, is proposed to overcome the limitations of the single-objective optimization. To verify the proposed method, the results of the proposed method are compared with those of the single-objective optimization. The comparison shows that the updated model from the multi-objective optimization is superior to the result of single-objective optimization in calculation time as well as the relative errors between the updated model and measurement.