• Health Policy and Management
• /
• v.18 no.1
• /
• pp.21-42
• /
• 2008

This study investigates economies of scale, cost complementarity and economies of scope for healthcare organizations using econometric approaches. The economies of scale appear to exist in each service provided by a hospital such as inpatient treatment services, outpatient treatment services, and other patient treatment services, respectively. When we test all services in aggregate level, it also indicates that the healthcare industry on average exhibits the economies of scale of 6 percent, which implies that scaling up hospital sizes will bring substantial cost savings to them Evidence shows that cost complementarity exists between outpatient services and other services for patients and, i.e., these other services for patients experience the reduction in marginal costs as the outputs of the outpatient services increase. For the economies of scope, they are present in most service areas; aggregate level services, outpatient services, and other services for patients, respectively. Inpatient treatment services, however, do not show any evidence of the economies of scope. Results show that the economies of scope are achieved by the general hospital type that provides all service areas such as inpatient treatments, outpatient treatments, and other services for patients. The existence of the economies of scope provides the rationale for extending the existing line of business in a hospital into more diverse areas of services where its benefit comes in the form of cost savings. In sum, it overall provides evidence that the M&As in this industry are encouraged to achieve cost reductions from the economies of scale and scope by changing the size and the output mix.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.10B
• /
• pp.1192-1199
• /
• 2011

The purpose of this paper is to test empirically whether the sunk cost fallacy occurres or not under the two-part tarriff and to give the desirable rate-making for minimizing sunk cost fallacy. According to the results of analysis highly paid monthly fee makes more traffics over the level of optimal consumption because of sunk cost fallacy. Therefore monthly fee reduction will cause the optimal consumption that is near the solution of their own utility function.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.12
• /
• pp.705-712
• /
• 2003

In this paper, we propose new unified methodologies of reliability and its cost evaluation in power distribution systems. The unified method means that the proposed reliability approaches consider both conventional evaluation factor, i.e. sustained interruptions and additional ones, i.e. momentary interruptions and voltage sags. Because the three voltage quality phenomena generally originate from the outages on distribution systems, the basic and additional reliability indices are summarized considering the fault clearing mechanism. The proposed unified method is divided into the reliability evaluation for calculating the reliability indices and reliability cost evaluation for assessing the damage of customer. The analytic and probabilistic methodologies are presented for each unified reliability and its cost evaluation. The time sequential Monte Carlo technique is used for the probabilistic method. The proposed DVL(Demand Varying Load) model is added to the reliability cost evaluation substituting the average load model. The proposed methods are tested using the modified RBTS(Roy Billinton Test System) form and historical reliability data of KEPCO(Korea Electric Power Corporation) system. The daily load profile of the each customer type in domestic are gathered for the DVL model. Through the case studies, it is verified that the proposed methods can be effectively applied to the distribution systems for more detail reliability assessment than conventional approaches.

• Land and Housing Review
• /
• v.1 no.1
• /
• pp.1-7
• /
• 2010

Case-based reasoning (CBR) method can make estimators understand the estimation process more clearly. Thus, CBR is widely used as a methodology for cost estimation. In CBR, the quality of case retrieval affects the relevance of retrieved cases and hence the overall quality of the reminding capability of CBR system. Thus, it is essential to retrieve relevant past cases for establishing a robust CBR system. Case retrieval needs the following tasks to obtain appropriate case(s); indexing, search, and matching (Aamodt and Plaza 1994). However, the previous CBR researches mostly deal with matching process that has limits such as accuracy and efficiency of case retrieval. In order to address this issue, this research presents a CBR cost model for building projects that has two-step retrieval process: decision tree and nearest neighbor methods. Specifically, the proposed cost model has indexing, search and matching modules. Features in the model are divided into shape-based and scale-based attributes. Based on these, decision tree is established for facilitating the search task and nearest neighbor method was utilized for matching task. In regard to applying nearest neighbor method, attribute weights are assigned using GA optimization and similarity is calculated using the principle of distance measuring. Thereafter, the proposed CBR cost model is developed using 174 cases and validated using 12 test cases.

• Korean Chemical Engineering Research
• /
• v.59 no.3
• /
• pp.467-479
• /
• 2021

Abstract: A kinetic model was developed for the dehydration of ethanol to ethylene based on two parallel reaction pathways. Kinetic parameters were estimated by fitting experimental data of powder catalysts in a lab-scale test, and the effectiveness factor was determined using data from pellet-type catalysts in bench-scale experiments. The developed model was used to design a multitubular fixed-bed reactor (MTR) and an adiabatic reactor (AR) at a 10 ton per day scale. The two different reactor types resulted in different process configurations: the MTR consumed the ethanol completely and did not produce the reaction intermediate, diethyl ether (DEE), resulting in simple separation trains at the expense of high equipment cost for the reactor, whereas the AR required azeotropic distillation and cryogenic distillation to recycle the unreacted ethanol and to separate the undesired DEE, respectively. Quantitative analysis based on the equipment and annual energy costs showed that, despite high equipment cost of the reactor, the MTR process had the advantages of high productivity and simple separation trains, whereas the use of additional separation trains in the AR process increased both the total equipment cost and the annual energy cost per unit production rate.

• Journal of Information Technology Services
• /
• v.10 no.4
• /
• pp.205-218
• /
• 2011

Unit testing which is the first task to perform software testing has a major impact on reducing s/w development cost and improving s/w quality. In order to make unit testing become the formal procedure rather than ad-hoc tasks performed by developer, the language-neutral measures are necessary in the programming which is able to specify the test cases. This paper presents a test assertion language for the language-neutral specification of the test cases. The suggested language is based on the ISO/IEC 24709-1, but it supports object oriented features and can describe test cases for unit testing. The test cases that are specified by the language can be used for generating test oracle source codes by test oracle generation tools.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.03a
• /
• pp.455-462
• /
• 2002

There exist several kinds of continuous consolidation tests to analyze the consolidation behavior of soft clay. The constant rate of strain (CRS) test has been adopted as a standard method by several countries, and some researches also have been peformed by domestic researchers. Among those, the constant pressure ratio (CPR) test is peformed with the constant ratio of excess porewater pressure to vertical effective stress. The test has the advantage of considerable reduction of duration time. In the study, the consolidation characteristics are analyzed by performing the CPR test as validate the pressure ratio with undisturbed soft clay and remolded clay, Also, results of the standard consolidation test and CRS test are compared to verify the CPR test can be employed for practical use. As a result, effects of variation of the pressure ratio on consolidation parameter are similar to the strain rate in the CRS test. Therefore, the test can be used to analyze the consolidation behavior of soft clay But the test have some problems such as expensive cost of equipment and highly skilled workmanship.

• Journal of Korean Society for Quality Management
• /
• v.43 no.4
• /
• pp.533-544
• /
• 2015

Purpose: The purpose of this study is to analyze the cost efficiency of food industry in JeollaNamdo. And this study is focused on the correlation between the economic efficiency of food industry and its cost efficiency, based on the analysis of 372 food companies' data in JeollaNamdo in 2012. Methods: DEA cost minimization is the measurement of the cost efficiency of JeollaNamdo food industry in 2012. In this study, the CCR and BBC models have been employed to analyze the decomposing cost efficiency-technical efficiency, allocative efficiency, and scale efficiency respectively. And the Spearman rank correlation and Wilcoxon signed rank test also have been employed to check the correlation and difference between the ranking orders based on the efficiency scores respectively. Results: For the CCR model, mean cost efficiency was found to be 0.084(0.54 for allocative efficiency and 0.19 for technical efficiency). For the BCC model, mean cost efficiency was found to be 0.252(0.453 for allocative efficiency and 0.564 for technical efficiency). Average scale efficiency was found to be 0.38. In analyzing the results, this study argues that the optimal way to improve cost efficiency is by reducing inputs proportionally and changing their combination. Conclusion: The efficiency scores of the two models show high correlation, whereas, the differences between them are also found to be significant. Hence, it should be cautious to select a suitable model when we do the research.

• International conference on construction engineering and project management
• /
• 2024.07a
• /
• pp.1322-1322
• /
• 2024

Reinforced concrete (RC) , a major contributor to resource depletion and harmful emissions, fuels research on optimizing its design. Optimizing RC structures is challenging due to the mix of discrete and continuous variables, hindering traditional differentiation-based methods. Thus, this study aims to optimize RC structures cost-effectively using deep reinforcement learning. When the Agent selects design variables, Environment checks design criteria based on KDS 14-20 code (South Korea) and calculates reward. The Agent updates its Neural Network with this reward. Target for optimization is a simply supported doubly RC beam, with design variables including cross-section dimensions, sizes and quantities of tension and compression reinforcement, and size of stirrups. We used 200,000 training sets and 336 test sets, each with live load, dead load, beam length variables. To exclude labeled data, multiple training iterations were conducted. In the initial training, the reward was the ratio of maximum possible cost at beam length to the designed structure's cost. Next iterations used the ratio of optimal values by the previous Agent to the current Agent as the reward. Training ended when the difference between optimal values from the previous and current Agent was within 1% for test data. Brute Force Algorithm was applied to the test set to calculate the actual cost-optimal design for validation. Results showed within 10% difference from actual optimal cost, indicating successful deep reinforcement learning application without labeled data. This study benefits the rapid and accurate calculation of optimized designs and construction processes in Building Information Modeling (BIM) applications.

• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.10
• /
• pp.829-835
• /
• 2016

Electro-Mechanical Actuator installed on the aircraft plays a key role in an aircraft's flight control through flight control computer. Reliable prediction of the actuator is important for the aircraft. To estimate the lifetime of a product, it is necessary to test full target life. However, it is very difficult to perform it due to the long life time of actuator but short period of development time with increasing cost. Therefore, accelerated life test has been used to reduce the test time for various reasons such as reducing product's development cycle and cost. In this paper, to predict the lifetime of the actuator, we analyzed the flight profile of aircraft and adapted the method of accelerated life test in order to accelerate failure modes that might occur under user conditions. We also set up an endurance test equipment for validating the demanded lifetime of an actuator and performed accelerated life test.