• Korean Journal of Poultry Science
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• v.19 no.3
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• pp.125-136
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• 1992

This study was conducted to estimate the effect of dietary alfalfa meal on the contents of egg yolk cholesterol, the levels of egg yolk pigmentation and the performance of laying hens. Alfalfa meal which was alternated wheat bran was supplied 0, 3.5 and 7%, respectively. Total 192 brown laying pullets of 47 weeks old were randomly assigned to the wire cages from July 23 to October 7, 1991 for 10 weeks. The results obtained were summarized as follows ： 1. The egg production was highest at 3.5% alfalfa meal level during the entire period. But there was no significant difference among treatments. 2. Egg weight increased in treatments 3.5 and 7% alfalfa meal supplementation significantly. (P<0.01). 3. Even though there was no significant difference, the daily egg mass was the highest at 3.5% of alfalfa meal level. 4. Daily feed intake was the highest at 3.5% of alfalfa meal level. However, feed conversion rate was the lowest among treatments. 5. The feed cost per kg egg mass in the treatment of 3.5% alfalfa meal was significantly lower than the other treatments. (P<0.05). 6. Shell thickness and shell weight in terms of egg shell quality were increased as the levels of alfalfa meal were increased. But there was no significant difference among treatments. 7, The egg yolk Pigmentation was improved significantly as the level of alfalfa meal was increased (P<0.01). 8.899 yolk cholesterol contents were decreased in the treatments of 3.5 and 7% alfalfa meal supplementation compared with those in the treatment of wheat bran only(P >0.05). The results of this study indicate that 3.5% alfalfa meal level was most effective and economical in laying hen.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.17-33
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• 2005

Highway design speed is a very important design element which determines highway design level. When determining highway design speed, one would estimate it utilizing the most likelihood of design speed and vehicle operating speed relationship. Existing operating speed prediction models only include highway geometric characteristics and their impacts on speed, which usually can not consider the impact of highway design speed on surrounding roadway environment and land use pattern. If this happens, excessive highway construction cost and huge environmental impact can occur. In this research project, a new vehicle operating speed prediction model was developed which can reflect the effect of surrounding roadway environment into vehicle speed prediction. The followings are the research findings : Firstly, highway terrain types and land use pattern on national roads were classified and integrated into drivers' visual recognition pattern. This was performed using a data management software. Secondly, the developed highway terrain types and land use pattern were related to vehicle speeds and it was found that there were significant statistical differences among vehicle speed for each different terrain and land use pattern. Thirdly. the General Linear Model analysis was employed to analyze the effects of highway geometric features, terrain types, and land use patterns. For two-lane highway and four-lane highway tested in this research project, it was found that R squares were 0.67 and 0.85, respectively. Additionally an optimal highway design speed range table, based on this research project. was proposed for practical use. This table can be reliably used on South Korean national road design, but discretion is required for applying this table to other types of highways including provincial roads and municipal roads.

• Journal of Korean Society of Transportation
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• v.32 no.2
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• pp.93-105
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• 2014

This study evaluated the relative efficiency of mobile emission reduction countermeasures through a Data Envelopment Analysis (DEA) approach and determined the priority of countermeasures based on the efficiency. Ten countermeasures currently applied for reducing greenhouse gases and air pollution materials were selected to make a scenario for evaluation. The reduction volumes of four air pollution materials(CO, HC, NOX, PM) and three greenhouse gases($CO_2$, $CH_4$, $N_2O$) for the year 2027, which is the last target year, were calculated by utilizing both a travel demand forecasting model and variable composite emission factors with respect to future travel patterns. To estimate the relative effectiveness of reduction countermeasures, this study performed a super-efficiency analysis among the Data Envelopment Analysis models. It was found that expanding the participation in self car-free day program was the most superior reduction measurement with 1.879 efficiency points, followed by expansion of exclusive bus lanes and promotion of CNG hybrid bus diffusion. The results of this study do not represent the absolute data for prioritizing reduction countermeasures for mobile greenhouse gases and air pollution materials. However, in terms of presenting the direction for establishing reduction countermeasures, this study may contribute to policy selection for mobile emission reduction measures and the establishment of systematic mid- and long-term reduction measures.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.2
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• pp.171-181
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• 2011

Recently, many studies have been attempted to save the cost of production and to build the ocean energy power generating system. The low-reflection structure with the wall-typed curtain which has a wave power generation system of OWC is known as the most effective energy conversion system. A three-dimensional numerical model was used to understand the characteristics of velocity of flows about compressed air and to estimate the pressure acting on the low-reflection structure due to the short-period waves. The three-dimensional numerical wave flume which is the model for the immiscible two-phase flow was applied in interpretation for this. The numerical simulation showed well about the changes in velocity of compressed air and the characteristics of pressure according to the change in the wave height and depth of the curtain wall. Additionally, the results found that there was the point of the maximum velocity of the compressed air when the reflection coefficient is at its lowest point.

• Environmental and Resource Economics Review
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• v.29 no.3
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• pp.363-388
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• 2020

The purposes of this study are to not only estimate optimal harvests and efforts using the surplus production methods for Spanish mackerel caught by multiple fishing gears, but provide dynamic optimal fisheries management for these gears using the current value Hamiltonian method. To achieve the above purposes this study uses several models such as Gavaris's general linear model for standardizing fishing efforts, surplus production method for estimating biological and technological coefficients, current value Hamiltonian method for estimating dynamic optimal harvest and efforts, and sensitivity analysis for diagnosing economic influences of these fisheries. As a result, this study showed that Spanish mackerel was overfished by multiple fishing gears based on surplus production method and the current value Hamiltonian method. Also, this study found that when the price and cost proportionally changed, the optimal harvest and fishing effort sensitively responded to the stock level of Spanish mackerel. Next, this study suggested that the multiple fishing gears for Spanish mackerel should reduce unnecessary costs such as operating time or inefficient fuel consumption. Finally, this study provided reasons Spanish mackerel should be included in the TAC system in a view of profit maximization based on sustainable use of the Spanish mackerel.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.5
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• pp.199-212
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• 2008

Software simulation has been widely used for the design and application development of a large-scale wireless sensor network. The degree of details of the simulation must be high to verify the behavior of the network and to estimate its execution time and power consumption of an application program as accurately as possible. But, as the degree of details becomes higher, the simulation time increases. Moreover, as the number of sensor nodes increases, the time tends to be extremely long. We propose an optimal-synchronous parallel discrete-event simulation method to shorten the time in a large-scale sensor network simulation. In this method, sensor nodes are partitioned into subsets, and each PC that is interconnected with others through a network is in charge of simulating one of the subsets. Results of experiments using the parallel simulator developed in this study show that, in the case of the large number of sensor nodes, the speedup tends to approach the square of the number of PCs participating in the simulation. In such a case, the ratio of the overhead due to parallel simulation to the total simulation time is so small that it can be ignored. Therefore, as long as PCs are available, the number of sensor nodes to be simulated is not limited. In addition, our parallel simulation environment can be constructed easily at the low cost because PCs interconnected through LAN are used without change.

• Journal of Korea Port Economic Association
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• v.29 no.4
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• pp.1-25
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• 2013

The purpose of this paper is to estimate economic benefits for the investment of railway transshipment system with non-powered turntable. The freight transport by railway can have decided advantages over trucks in terms of energy efficiency, emissions and cost for certain freight movements, just as transportation in the metropolitan region can have great advantages over driving truck. But the freight transport by truck should gain significant mobility benefits from a freight railway system. Thus, the railway transshipment system with non-powered turntable which is coupled railway transport advantages with load transport advantages has been developed and used in the european countries. This research has conducted the empirical analysis, by calculating the investment of railway transshipment system with non-powered turntable. The key factor for the economic benefits for the non-powered turntable is the utilizing throughputs. This demand is influenced by the throughput in the railway transshipment system. The main results of this paper are as follows: railway transshipment system with non-powered turntable does not have economic benefit for investment. We recommend that the plan for investment has to be considered the modification.

• Environmental and Resource Economics Review
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• v.21 no.3
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• pp.595-625
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• 2012

Recently environment-friendly pellet boilers have interests as emissions of greenhouse gases are regulated internationally and energy security becomes more important to oil addicted countries including Republic of Korea. But the Korean market for pellet boilers is on the initial stage due to the high production costs relative to other conventional boilers. Hence the Korean government has supported financially and promoted the pellet boiler business. In this sense, it would contribute market stratergy and effective promotion policy for both of the government and private companies if we can forecast market shares of pellet boilers appropriately. For this purpose, this study surveyed potential consumers' preferences on pellet boilers among various alternatives using a choice experiment reflecting intangible costs. As the market share of new technology increases, intangible costs decline. According to different intangible cost scenarios, we experimented people's preferences on oil, gas, electric, and pellet boilers. A multinomial logit model was employed to estimate coefficient parameters of common attributes for various alternative boilers. Based on the estimates, we forecasted market shares of individual boilers. We found that as intangible costs decline, the market share of pellet boiler increase substantically while market shares of electric and gas boilers decrease dramatically. The market share of oil boiler did not change significantly. Meanwhile, as people are more rich, more educated, and exposed to advertisement on pellet boilers, the likelihood of choosing the pellet boiler increases.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.234-244
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• 2007

Both competent authorities and private entrepreneurs face plenty of risks when negotiating BTO(Build Transfer Operation) methods of PPI(Private Participations in Infrastructures) projects. Also, success and failure of projects largely depend on the concession agreement contract. In this study, for more efficient negotiation, major issues are examined, and quantitatively analyzed to find out not only the relationship but also the characteristics of which these issues share. Questionnaire research was conducted through both research and by experts who were divided into an ordering agency, design company and constructor. Characteristics of major issues were quantitatively analyzed using the Likert index method, ANOVA(ANalysis of VAriance) and AHP(Analytic Hierarchy Process) analysis. Case studies were examined in order to estimate construction cost, rates of return, government finance support, level of operation-revenues guarantees, estimating operational costs and usage fees. With these 6 items, relative priority, relative impression which is sensible to risk and extent of difficulty in presenting data which is objective were quantitatively analyzed by the ordering agency, design company and constructor groups. From the analysis, there were some similarities between the design company and constructor groups while there was less of similarities between the ordering agency and design company or constructor. The government is diversifying the methods of project promotion, and PPI project from infrastructure-centered to public culture facilities are being expand. The current study will provide not only supporting efficient negotiation but also revitalizing PPI projects.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.157-167
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• 2005

Seoul metropolitan public transport reform results in the introduction of the semi-public operation and distance-based fare policies. With implementation of these policies, public transport revenue allocation has been (will be) evolved very complicated because the existing revenue allocation issues have not only been clearly solved, which is generated by the combined relationship among Korea Railroad Corporation (KRC). Seoul Metropolitan Subway Corporation (SMSC). Seoul Metropolitan Rapid Transit Corporation (SMRTC), and Incheon Rapid Transit Corporation (IRTC), but also the revenue allocation problem between bus and urban railroad-related organizations need to be considered in this combined framework. On top of that. based on the future plans such as the private sector's railroad construction plan(s), the light rail transit construction plans of several local governments and the join of remained bus lines of Seoul metropolitan areas, it is understood that the revenue allocation among public transport operating organization will become one of main issues of operation organization as well as local and central governments. As a basic approach for revenue allocation of public transport operation organizations, the purpose of this paper is to propose an integrated model applicable to estimate degree of service contribution in passenger carriage in the combined public transport network. With a hypothesis that the complete electronic card system is deployed, this paper supposes every passenger's loading and alighting stations is recordable. Thereby, this paper limits research scope as to Seoul metropolitan railroad area since used route(s) between origin and destination stations can not be traceded because transfer stations each passenger path through is not recorded. Each model proposed in the paper is as follows: 1. a generalized cost reflecting passenger's transfer behavior; 2.a K path model for determining similar routes between O-D; 3.an assignment model for loading O-D trips onto the detected similar routes using Logit Model.