• Journal of Fisheries and Marine Sciences Education
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• v.18 no.3
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• pp.261-271
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• 2006

The present study is aimed at evaluating the economic effectiveness of Abalone, haliotis discus hanai Releasing Project(ARP) conducted in the fishing ground owned by a fishing village in Ulsan, Korea. The results were summarized as follows: First, an average ratio of released abalones in the total landing after releasing is shown to be 85.0%. Second, the recapture rate of released abalones is 46.8%, exceeding the recapture rate of BEP(Break-Even-Point), 22.9%. Third, it is evaluated that total economic effectiveness of the ARP is 6.7-6.8 times, net effectiveness is 2.2-2.3 times, and the NPV(Net Present Value) discounted by a 8% interest rate is 474, 635 thousand wons, indicating the project is profitable. Considerable parts of the positive results on the ARP are based on some beneficial conditions, including the selection of favorable releasing sites, best self-regulation system of a fishing village for preservation of seaweed facilities and continued activities for protecting small abalones and their rearing. These results imply that the success of the ARP would be primarily dependent upon the selection of releasing site and effective management system after releasing.

• Journal of Forest and Environmental Science
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• v.35 no.3
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• pp.173-180
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• 2019

This study determined the economic impact of environment-friendly cultivation and the optimal cultivation area of Omija (Korean for Schisandra chinensis Baillon) for full-time farmers by analyzing the management performance of existing Omija cultivators. The study divided the target income into urban household income and Omija farm income, and estimate the optimal cultivation area by substituting the target profit from the cost-volume-profit analysis model. The optimum cultivation area was 1.4 ha for general cultivation, 1.08 ha for organic cultivation, and 1.18 ha for pesticide-free farming cultivation considering the average urban household income as the target, and 0.81 ha for general cultivation, 0.63 ha for organic cultivation, and 0.69 ha for pesticide-free farming, considering the average 2012 farm household income as the target. Therefore, the study reached conclusion that it is necessary to secure the price of Omija farm and stable support for income increase. Therefore, the support plan for income stabilization of Omija farm should be considered. Especially, the central government should provide various policies and financial support to help the optimal cultivation area of Omija Farm.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.4
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• pp.65-74
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• 2018

The primary objective of this study is to develop a conceptual design of automated pothole patching machine that improves the conventional work in safety, quality, and productivity. For this, the following research works are conducted sequentially; 1)literature review, 2)selection of element technology for conceptual design, 3)deduction of work process and conceptual design, 4)life cycle cost analysis of the conceptual design. As a result, X-Y table telescopic manipulator, pothole patching end effector, realtime pothole recognizer, 3D pothole volume profiler, automated pothole patching machine controller are selected as core technologies. Furthermore, a conceptual design and working process of an automated pothole patching machine are developed based on the core technologies. According to the life cycle cost analysis result, the cost of the automated method was 38.3% less than that of the conventional method, and the economic efficiency was also superior(ROR 77.1%, Break-even Point 23.8month). It is expected that the application range and impact on the construction industry will be enormous due to the increasing trend of road maintenance market.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.2
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• pp.37-44
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• 2019

The primary objective of this study is to develop a prototype of all-in-one attachment-based PHC pile head cutting robot that improves the conventional work in safety, productivity, and quality. For this, the following research works are conducted sequentially; 1)literature review, 2)development of an all-in-one attachment-based PHC pile head cutting robot prototype, 3)performance evaluation of each device, 4)economic analysis of an automated method. As a result, PHC pile cutting level sensing device, PHC pile cutting device, PHC pile handling device are developed. Futhermore, working process of an automated method is developed based on result of performance evaluation. According to the economic analysis result, the cost of the automated method was 21.37% less than that of the conventional method, and the economic efficiency was also superior(ROR 215.44%, Break-even Point 5.52month). It is expected that conclusions for future improvements are used in the development of the all-in-one attachment-based PHC pile head cutting robot to practical use.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.177-185
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• 2022

Hydrogen risk in the containment filtered venting system (CFVS) vessel was analyzed, considering operation pressure and modes with the effect of PAR and accident scenarios. The CFVS is to depressurize the containment by venting the containment atmosphere through the filtering system. The CFVS could be subject to hydrogen risk due to the change of atmospheric conditions while the containment atmosphere passes through the CFVS. It was found that hydrogen risk increased as the CFVS opening pressure was set higher because more combustible gases generated by Molten Core Concrete Interaction flowed into the CFVS. Hydrogen risk was independent of operation modes and found only at the early phase of venting both for continuous and cyclic operation modes. With PAR, hydrogen risk appeared only at the 0.9 MPa opening pressure for Station Black-Out accidents. Without PAR, however, hydrogen risk appeared even with the CFVS opening set-point of 0.5 MPa. In a slow accident like SBO, hydrogen risk was more threatening than a fast accident like Large Break Loss-of-Coolant Accident. Through this study, it is recommended to set the CFVS opening pressure lower than 0.9 MPa and to operate it in the cyclic mode to keep the CFVS available as long as possible.

• Journal of Animal Science and Technology
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• v.50 no.4
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• pp.561-572
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• 2008

Responses of real-time control parameters, such as ORP, DO and pH, to the conditions of biological animal wastewater treatment process were examined to evaluate the stability of real-time control using each parameter. Also an optimum index for supplemental carbon source addition based on NOx-N level was determined under a consideration of denitrification rate by endogenous respiration of microorganism and residual organic matter in liquor. Experiment was performed with lab-scale sequencing batch reactor(SBR) and working volume of the process was 45L. The distinctive nitrogen break point(NBP) on ORP-and DO-time profiles, which mean the termination of nitrification, started disappearing with the maintenance of low NH4-N loading rate. Also the NBP on ORP-and DO-time profiles was no longer observed when high NOx-N was loaded into the reactor, and the sensitivity of ORP became dull with the increase of NOx-N level. However, the distinctive NBP was constantly occurred on pH(mV)-time profile, maintaining unique profile patterns. This stable occurrence of NBP on pH(mV)-time profile was lasted even at very high NOx-N:NH4-N ratio(over 80:1) in reactor, and the specific point could be easily detected by tracking moving slope change(MSC) of the curve. Revelation of NBP on pH(mV)-time profile and recognition of the realtime control point using MSC were stable at a condition of over 300mg/L NOx-N level in reactor. The occurrence of distinctive NBP was persistent on pH(mV)-time profile even at a level of 10,000mg/L STOC(soluble total organic carbon) and the recognition of NBP was feasible by tracing MSC, but that point on ORP and DO-time profiles began to disappear with the increase of STOC level in reactor. The denitrfication rate by endogenous respiration and residual organic matter was about 0.4mg/L.hr., and it was found that 0.83 would be accepted as an index for supplemental carbon source addition when 0.1 of safety factor was applied.

• The Korean Journal of Applied Statistics
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• v.19 no.1
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• pp.97-110
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• 2006

Since it is well-established that even high quality data tend to contain outliers, one would expect fat? greater reliance on robust regression techniques than is actually observed. But most of all robust regression estimators suffers from the computational difficulties and the lower efficiency than the least squares under the normal error model. The weighted self-tuning estimator (WSTE) recently suggested by Lee (2004) has no more computational difficulty and it has the asymptotic normality and the high break-down point simultaneously. Although it has better properties than the other robust estimators, WSTE does not have full efficiency under the normal error model through the weighted least squares which is widely used. This paper introduces a new approach as called the reweighted WSTE (RWSTE), whose scale estimator is adaptively estimated by the self-tuning constant. A Monte Carlo study shows that new approach has better behavior than the general weighted least squares method under the normal model and the large data.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.219-228
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• 2015

Purpose: The current study was performed to compare the difference in binocular visual function depending on variable background colors at near work. Method: Fifty four adults (18 males, 34 females) who consented to the present study and had no ocular disease, ocular surgery history, strabismus and amblyopia with normal binocular vision were participated into this study. The subjects were asked to read the novels with black letter printed on white, red, green and blue background for 15 min. Then, their heterophoria, AC/A ratio, near point of convergence, accommodation facility, relative accommodation and vergence were measured before and after reading. The difference of measurements were compared. Result: Overall heterophoria was tended to decrease with regardless of background color. AC/A ratio showed a tendency of increase after reading the novels with all backgrounds except white background. Near point of convergence was significantly increased compared to before reading at all background color. Accommodative facility of dominant and non-dominant eyes were also significantly increased after reading however, binocular accommodative facility showed a tendency of decrease. Negative relative accommodation also decreased at all background colors however, the change of positive relative accommodation was not significantly different. In case of vergence, there was significant difference in break point of far BO and recovery point of far BI by the wavelength of background color. Conclusions: From the results, it was known there is convergence change depending on the wavelength of light even though same amount of accommodation and convergence is required when doing near work for certain period. Thus, it can be suggested that the adjustment of the near working environment which perception of various color was required, should be conducted according to the main wavelength.

• The Journal of Korean Association of Computer Education
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• v.8 no.1
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• pp.55-63
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• 2005

Recently, web-based E-learning systems have entered the spotlight by providing new learning environments that break down spatial and temporal limitations. The key to building the web-based E-learning system is in determining how to effectively use the system and to evaluate the degree of learning achieved by the students that use it. In traditional off-line learning systems, we can evaluate students by counting how many questions, designed to evaluate their learning achievement, he or she answers correctly within a predetermined time limit. But this method would make individualized learning, a strong point of E-learning systems, impossible because these systems provide same learning strategy to all students even though they achieve a different level of learning. Therefore, in this paper, I will find any relationships between given test answers using fuzzy implication theory, I call these fuzzy correlations, and then generate evaluation results that are reflected in those relationships. I will compare the differences between this evaluation method and a traditional evaluation method where a student takes a test to evaluate his or her learning achievement after some learning period. Finally, I will discuss how we can use these results in individualized learning.

• Journal of the Korea Fashion and Costume Design Association
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• v.4 no.3
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• pp.75-87
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• 2002

The nineteenth century was a watershed - the extreme point of difference in the style of fashion dress and in the roles men and women played in society. This conviction has its roots in the socioeconomic changes of the 19th century and the industrial revolution, and the new working bourgeoisie' value, fashion and taste were on the rise. The bourgeois, who was not considered as having infallible taste, was looking for its own style, while on the other hand it was competing with the nobility. Therefore bourgeois' own etiquette and taste were appeared. There was ideals which the middle classes were hungry for, and it became the basis of judging an individual. The bourgeois tried to get social approval and used fashion was the mean of it. Bourgeois women fashion has a funtion as a complete symbol of the status, wealth and leisure in a patriachal society. Not only the Bourgeois tried to control themselves and to achieve the virtue of moderation, chastity and obedience by the restrictive costume, but also extravagant and cumbersome dresses has a kind of compensative funtion against a sober and simple men's dress. There was a reformative movement to break out of the legal, economic and social restrictions within the confines of respectable Victorian Society. The process of reform was long and slow for not only did laws be changed but the barriers of prejudice in a society convinced of man s mental and physical superiority had to be overcome. But even though there were many difficulties, a small number of progressive women challenged the social recognition and role of women and decisively refused the restrictive and ostentative fashion. Victorian costume was also criticized in the medical and aesthetic aspect for their impracticality. As a result, more funtional and practical women's clothes has appeared, but it have resulted in a peculiar hybrid of traditional female attire in combination with the more uncomfortable aspects of men's clothes. However it was becoming an essential look for new women who were the equals of men and wanted to be treated as such.