• Ocean and Polar Research
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• v.36 no.3
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• pp.289-302
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• 2014

This paper aims to evaluate the indirect economic damages to anglers of the marine recreational charter caused by marine pollution associated with the Herbei Spirit vessel, which spilled 12,547 kl of crude oil in Taean coastal areas in December 2007. In order to evaluate the indirect cost to anglers of the charter fishing, consumer surplus for charter fishing is estimated using a Poisson model (PM), a negative binomial model (NBM), a truncated Poisson model (TPM), and a truncated negative binomial model (TNBM), which account for the characteristics of count data (non-negative discrete data), for individual travel cost method (ITCM). Because of over-dispersion problem in PM and TPM, NBM and TNBM are considered to be more appropriate statistically. All parameters such as income, fishing careers, travel cost and catch that are estimated are statistically significant and theoretically valid. Based on TNBM results, consumer surplus per trip and per person was estimated to be 277 thousand won, total consumer surplus per person and per year about 2.3 million won, and the marginal effect of consumer surplus on % changes in catch rate is about 33 thousand won. The consumer surplus was converted into total indirect economic damages for aggregation which are evaluated to be 125 billion won, reflecting the number of anglers and damage rate.

• Ecology and Resilient Infrastructure
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• v.4 no.3
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• pp.180-185
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• 2017

Restoration of min-impacted arable land is often performed through stabilization of trace elements by amendment treatment combined with (clean) soil covering on the surface. Recently, soil loss problem from sloping remediated agricultural lands has risen as an emerging concern. In this study, efficacy of aggregation formation was assessed by single and binary treatments of four potential amendments (bentonite, lime, organic matter, and steel slag) applied on three cover soils having different clay contents (9.4, 14.7, and 21.2% for A, B, and C soils respectively). In results of single treatments, 5% organic matter for A soil and 5% lime for B and C soils were found most effective for the aggregation formation compared to the respective controls (without amendments). Among nine binary treatments, 3% organic matter + 1% lime for A soil and 1% organic matter + 3% lime for both B and C soils led to the highest formation of aggregation (30.4, 25.0, and 36.5% for A, B, and C soils). For a site-application, the soil erodibility difference between the cover soils (0.045, 0.051, and 0.054 for A, B, and C soils, respectively) and the national average of arable land (0.032) was assumed to be compensated by amendment addition, which is equivalent to 29.1% aggregation formation. To achieve the aggregation goal, 5% lime for A and B soils and 3% lime for C soil were best in the consideration of benefit/cost, thereby effectively and economically reducing soil loss from sloping remediation site. Soil alkalinity induced by lime treatment was not considered in this work.

• Biomedical Science Letters
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• v.10 no.4
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• pp.391-395
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• 2004

The demand for the production of gene-defective mice from embryonic stem (ES) cells is increasing to clarify decisive gene function in vivo. Although blastocyst injection is widely used to generate ES cell-mediated knockout mice, coculture method has been alternatively used because of several advantages, such as low cost and simple procedure. Thus, this experiment was designed to demonstrate the feasibility of the coculture method using J1 ES cells, which are known to be efficient for blastocyst injection. Eight-cell embryos were harvested from 2.5 days post-coitum (dpc), denuded with acid tyrode's solution, and transferred onto trypsinized J1 ES cells. Aggregation was carried out following two typical methods, which are simple coculture method and aggregation in groove prepared by aggregation needle. Successfully aggregated-embryos were developed to blastocysts for 24 h and transferred into uterus of pseudo-pregnant foster mother. Chimeric offspring was judged by coat pigmentation. In this study, we could obtain chimeric mice from all the two aggregation methods, but the chimera production efficiencies in coculture using groove were three times higher at least than those in the other group. In conclusion, these observations suggest that coculture method should be available for production of knockout mice from J1 ES cells. Presently, the germ-line transmission rates of the chimeras produced from the two methods are under investigation.

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.501-512
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• 2012

Social welfare maximization in a double-sided auction market is performed by implementing an aggregation-based particle swarm optimization (CAPSO) algorithm for optimal placement and sizing of one Static Synchronous Series Compensator (SSSC) device. Dallied simulation results (without/with line flow constraints and without/with SSSC) are generated to demonstrate the impact of SSSC on the congestion levels of the modified IEEE 14-bus test system. The proposed CAPSO algorithm employs conventional quadratic smooth and augmented quadratic nonsmooth generator cost curves with sine components to improve the accurate of the model by incorporating the valve loading effects. CAPSO also employs quadratic smooth consumer benefit functions. The proposed approach relies on particle swarm optimization to capture the near-optimal GenCos and DisCos, as well as the location and rating of SSSC while the Newton based load flow solution minimizes the mismatch equations. Simulation results of the proposed CAPSO algorithm are compared to solutions obtained by sequential quadratic programming (SQP) and a recently implemented Fuzzy based genetic algorithm (Fuzzy-GA). The main contributions are inclusion of customer benefit in the congestion management objective function, consideration of nonsmooth generator characteristics and the utilization of a coordinated aggregation-based PSO for locating/sizing of SSSC.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.1
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• pp.123-140
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• 1997

In this paper we consider closed flow line systems with samploing inspections. The total number of parts in the system is assumed to be N. The processings carried out of each station do not always meet the requirement of quality. Therefore, upon completion of its processing at each station, a part is inspected to determine whether the processings meet the requirement of quality or not. We assume that inspection are done on a random basis. If a part is found to be defective by an inspection, it is fed back to the apropriate station. Two different cases will be considered in this study : a three-station flow line system with infinite buffers and a two-station flow line system with finite buffers. For each case, we will develop an exact method to obtain the performance measures such as throughput, machinen utilization, average outgoing quality and manufacturing lead time. For the case of the two-station flow line system ith finite buffers, we will also develop an approximation method using a stage-aggregation technique. Then using buffers, we will also develop an approximation method using a stage-aggregation technique. Then using these results, we will try to find an optimal inspection policy which maximizes the expected net profit under a certain cost structure. Although we present the results only for the two or three station flow line system in this paper, the results obtained in this paper can be extended easily to the system which consists of more than two or three stations.

• The Transactions of the Korea Information Processing Society
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• v.3 no.3
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• pp.655-671
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• 1996

Using object relationship table, this study proposes an efficient indexing technique for accessing both aggregation and inheritance hierarchies in object- oriented databases. This indexing technique uses the information on the aggregation and inheritance relationship between classes and the information on referencing instances as meta data. As a result, the technique makes it possible to effectively evaluates various queries navigating between tables. The study compares the proposed technique with the existing indexing techniques and discusses its useful- ness. It also provides the result of simulating its performance in terms of storage and retrieval cost.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.1-10
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• 2019

This Dietary cholesterol augments lipid profile and primes production and activation of platelets, leading to development of atherosclerosis which produce several detrimental effects on cardiovascular health. Ethnomedicine and Mediterranean diet are natural sources and cost effective modes against several ailments including cardiovascular diseases while fermented foods have gained interest due to their increased nutrient profile, enhanced bioavailability and efficacy. Garlic has been known to reduce cholesterol and inhibit platelet activation. We examined whether fermented garlic ameliorates effects of hypercholesterolemia and platelet functions in rats. Methodology: Male SD rats were fed with hypercholesterolemia diet and treated with spirulina, fermented and non-fermented preparations of garlic for one month. Platelet aggregation and granule secretion were assessed to evaluate platelet activation. Liver and kidney weights, lipid and enzymatic profile of serum and whole blood analysis was performed. Expressions of SREBP, ACAT-2 and HMG-CoA were assessed using RT-PCR while liver and adipose tissues were analyzed for histological changes. Both fermented and non-fermented garlic inhibited platelet aggregation and granule secretion while fermented garlic showed greater inhibitor tendency. Fermented garlic significantly reduced liver weight and triglycerides concentrations than non-fermented garlic. Similarly, fermented garlic greatly abrogated the detrimental effects of steatosis on liver and adipose tissues. Fermented garlic significantly improved lipid profile and modulated platelet functions, thereby inhibiting atherosclerosis and platelet related cardiovascular disorders.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.97-106
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• 2011

Mode choice model is an essential element for estimating- the demand of new means of transportation in the planning stage as well as in the establishment phase. In general, current demand analysis model developed for the mode choice analysis applies common parameters of utility function in each region which causes inaccuracy in forecasting mode choice behavior. Several critical problems from using common parameters are: a common parameter set can not reflect different distribution of coefficient for travel time and travel cost by different population. Consequently, the resulting model fails to accurately explain policy variables such as travel time and travel cost. In particular, the nonlinear logit model applied to aggregation data is vulnerable to the aggregation error. The purpose of this paper is to consider the regional characteristics by adopting the parameters fitted to each area, so as to reduce prediction errors and enhance accuracy of the resulting mode choice model. In order to estimate parameter of each area, this study used Household Travel Survey Data of Metropolitan Transportation Authority. For the verification of the model, the value of time by marginal rate of substitution is evaluated and statistical test for resulting coefficients is also carried out. In order to crosscheck the applicability and reliability of the model, changes in mode choice are analyzed when Seoul subway line 9 is newly opened and the results are compared with those from the existing model developed without considering the regional characteristics.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.5
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• pp.1223-1237
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• 2024

Autonomous vehicles use onboard sensors to sense the surrounding environment. In complex autonomous driving scenarios, the detection and recognition capabilities are constrained, which may result in serious accidents. An efficient way to enhance the detection and recognition capabilities is establishing collaborations with the neighbor vehicles. However, the collaborations introduce additional challenges in terms of the data heterogeneity, communication cost, and data privacy. In this paper, a novel personalized federated learning framework is proposed for addressing the challenges and enabling efficient collaborations in autonomous driving environment. For obtaining a global model, vehicles perform local training and transmit logits to a central unit instead of the entire model, and thus the communication cost is minimized, and the data privacy is protected. Then, the inference similarity is derived for capturing the characteristics of data heterogeneity. The vehicles are divided into clusters based on the inference similarity and a weighted aggregation is performed within a cluster. Finally, the vehicles download the corresponding aggregated global model and train a personalized model which is personalized for the cluster that has similar data distribution, so that accuracy is not affected by heterogeneous data. Experimental results demonstrate significant advantages of our proposed method in improving the efficiency of collaborative perception and reducing communication cost.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.533-546
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• 2003

for the low information goods which will be traded through Internet is impossible to manage with previously existed payment system. The reason is that it's not economic because the management cost is bigger than the benefit of the information goods trade. Therefore, recently, there have been micropaymentresearches such as "Milicent", "PayWord", "MicroMint", and "iKP", etc. Though these methods don't have any problem with the low cost of the mechanism and the satisfaction of adequate security, they have big problem with the use of the unnecessary account and the aggregation of payment bill. The PayHash system which has been developed in this study simplifies the system's mechanism with "one-way hash function" which is used in generation, payment, and verification of the bill. And the system removed the generation and use of unnecessary account by making one customer have one account. The system solve the problem of the payment aggregation by using the last payment hash value and its index. And the system improves its performance by reducing the use of "digital signature" drastically, as well. As the result of this study, the PayHash system made it possible for the participants of the Internet Commerce to trade the lowest cost goods through efficient maintenance.o trade the lowest cost goods through efficient maintenance.