• Journal of Korean Society of Environmental Engineers
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• v.30 no.2
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• pp.168-174
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• 2008

Diagnosis on setteability based on human operator's experimental knowledge, which could be established by long term operation, is a limit factor to construction of automation control system in wastewater treatment plant. On-line SVI(Sludge Volume Index) analyzer was developed which can measure SV30 automatically by image capture and image analysis method. In this paper, information got by settling process was studied using On-line SVI analyzer for better operation & management of WWTPs. First, SV30 detection algorithm was developed using image capture and image analysis for settling test and it showed that automatic detection is feasible even if deflocculation and bulking was occurred. Second, turbidity assessment model was developed using image analysis.

• Korean Journal of Cognitive Science
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• v.22 no.2
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• pp.173-192
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• 2011

The visual system applies previously learned contextual knowledge to facilitate the perception and encoding of scenes. When extrapolation following the employment of contextual information occurs, it sometimes leads to scene memory distortion: people report as if they saw more than they actually had seen. This phenomenon is called the "boundary extension" effect (Intraub & Richardson, 1989). The present study aimed to clarify the effects of contextual information on boundary extension in a more systematic way. Based on the assumption that it is harder to extract contextual information from inverted scenes compared to intact scenes, we presented inverted scenes either during encoding or retrieval to manipulate the level of contextual information and compared the magnitude of boundary extension effect for upright versus inverted scenes. In a series of experiments, we found that scene inversion during encoding, but not during retrieval, significantly reduced boundary extension. Showing reduced memory distortion for inverted scenes, the current study directly demonstrated that access to contextual information is a critical component of scene extrapolation process.

• Journal of Korean Society of Rural Planning
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• v.19 no.2
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• pp.163-172
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• 2013

The purpose of this study is to survey on parents' preference and estimate parents' Willingness to pay(WTP) for after-school rural experience program in daegu city by choice experiment(CE). The results of this study are as follows; First, we divided after-school rural experience program into three types, namely: nature seeing, play exercise and learning experience. Second, the study has shown that parents prefer learning experience among those after-school rural experience programs. Among attributes which form a experience program, instructor certificates, consuming time and expense for participant are statistically effecting significant impact. Third, the result of estimation on willingness to pay for development of after-school rural experience program is as follow. The willingness to pay for learning experience is 6,337won, willingness to pay for instructor certificates is 14,102won and it for consuming time is 2,926won. Therefore, composition centering learning experience is better and instructor who has expert certificate is required. It is much better to compose that the consuming time is longer and the expense for experience is lower. But there is limitation because this survey was conducted based on an assumption, so it could read over estimation problem. The result of this study may provide useful information to develop after-school rural experience program using rural resources and to improve rural tourism policy.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.103-112
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• 1996

Optimal pricing research in general has been focused on profit maximizing strategy under the given product life-time T. Here we have tried to study the effect of uncertain product life-time on dynamic optimal pricing strategy. In reality, the life-time of product is more likely to be uncertain and not known as well. In terms of approximating the model to the concerned reality, so-called model validity, it seems to be more desirable to consider the uncertainty of product life-time into the optimal pricing strategy model, For this purpose, we tried two different approaches. One is to consider diverse product life-time probability functions under fixed life-time T. In this case, we might have the same product life-time as the previous study, but the process could be different in the expectation of product's discontinuity. The other is that life-time itself is not determined and thus it is the situation in which we can only decide optimal price on incremental basis. The former is the situation in which although we got some strong guess on life-time of a certain product, the pattern of expected life-time probability could be different. The question is what could be optimal pricing strategies on such different product life-time situations. But since in the latter, we don't assume any idea on the life-time of product. proper optimal pricing could be derived only from the past prices and diffusion information. While the latter seems to be safer in the aspect of model assumption, the former could be more realistic because we might have more or less a prior knowledge on the product life-time itself.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.7
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• pp.680-693
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• 2008

Recent studies on XML filtering assume that all data sources follow a single global schema defined in a filtering system. However, beyond this simple assumption, a filtering system can provide a service that allows data publishers to have their own schema; hence, the data sources will become heterogeneous. The number of data sources is expected to be large in a filtering system and the data sources are frequently published, updated, and disappeared, that is, dynamic. In this paper, we introduce implementing a simple and efficient XPath query translation method for such a dynamic environment. The method is especially targeted for a query which is composed based only on users' knowledge and experience without a graphical guidance of the global schema. When a user queries a large number of heterogeneous data, there is a high possibility that the query is not consistent with the same local schema assumed by the user. Our query translation method also supports a function for this problem. Some experimental results for query translation performance have shown that our method has reasonable performance, and is more practical than the existing method.

• Korean Journal of Oriental Medicine
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• v.18 no.3
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• pp.133-139
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• 2012

Objective : UMLS is 'Ontology' which establishes the database for medical terminology by gathering various medical vocabularies representing same fundamental concepts. Method : Although Chinese character are represented in the Chinese part of Korean Unicode system in a computer, writing of Chinese characters is vary depending on Chinese input systems and Chinese writers' levels of knowledge. As the result of this, representation of Chinese writing in a computer will be considerably different from an old Chinese document. Therefore, a meaningful relationship between digital Chinese terminology and translated Korean is necessary in order to build Ontology for Chinese medical terms from Oriental medical prescription in a computer system. Result : This research will present 1:1 mapping information among the Chinese characters used in the Oriental medical prescription with analysis of 'same character different sound' and 'same meaning different shape' in Chinese part of Unicode systems. Conclusions : Furthermore, the research will provide top-down menu of relationship between Chinese term and Korean term in medical prescription with assumption of that the Oriental medical prescription has its own unique meaning.

• Journal of The Korean Association For Science Education
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• v.14 no.3
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• pp.272-284
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• 1994

The aim of this research was to compare and analyze the children's ideas on evaporation and condensation between pre- and post-intervention. Forty-eight children from six elementary schools in Seoul and Kyung Ki provinces were sampled by stratified random sampling. A set of structured activities was then provided which allow children to explore evaporation and condensation phenomena. All of these activities had a preliminary phase which required the child to predict or speculate on evaporation and condensation using their existing knowledge. These structured activities on evaporation and condensation were reviewed by three professors and eigth primary school teachers. Their comments were used to revise the original contents of the structured activities. The data analysed were gathered by the questionaire and the interview. Pre- and post-intervention data related to evaporation and condensation were collected by the same teacher, and analysed into the same category scheme. Data coding was carried out several times by the researcher to ensure reliablity. Data collected were then classified and analyzed according to the types of children's ideas. The findings of this study were as follows: Results of this study showed that the the vocabulary used to describe the evaporation phenomena varied according to the context, and the scientific term "evaporated" was more frequently used by the older children after post-intervention. But everyday terms such as"dried up","disappered", "gone up" were also used by children as much as the level of pre-intervention. Scientific conception on the location of evaporated water, the factor of evaporation, the ideas about getting the water back and assumption about the physical state of the missing water has been increased for the most of the children after intervention. It was found that the intervention using was effective SPACE strategies regardless of the grade level of the children.

• The Journal of the Acoustical Society of Korea
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• v.20 no.3
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• pp.76-82
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• 2001

Most fluid machines can be considered as periodic noise sources when operated under constant conditions, which allows for a frequency domain representation of the source and the associated acoustic field In the duct. In such a representation, the source is characterized by frequency-dependent values of both strength and impedance. Although knowledge of these values can be gained by either experimentation or by modeling, one-port acoustic characteristics of an in-duct source with high flow velocity, high temperature, and high sound level can be measured only by the multiload method using an overdetermined set of open pipes with different lengths as applied loads. However, the problem is that negative source resistances have been often measured. This paper reviews the possible causes of the problem, with reference to experimental and theoretical results, in an attempt to clarify the issue. A new interpretation is given for the violation of basic assumptions and the defect in the algorithm of multiload method. The major cause and mechanism of the problem is due to the violation of time invariance assumption of the source and the load impedance can seriously affect the final measured result of source impedance.

• The Journal of Korean Association of Computer Education
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• v.4 no.1
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• pp.127-134
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• 2001

Many teachers at vocational high schools have had difficulties overcoming the gap between what students know and what students have to achieve in many topics. Mathematics is toughest of all, since most of textbooks in electronics are assuming student's basic knowledge in math. Considering that many students with very low achievements are entering vocational high schools, reality is far from such assumption. Inevitably, we have to face two difficult questions; do we have enough time to teach these kids all the math that they need in two years? If not, what alternatives we should adopt? We just do not have enough time and therefore find out a way to cope with harsh reality. According to our preliminary study, we suggest that multimedia-based CAI may be the best way to attack this problem. From hardware point of view, fortunately, many of vocational high schools are reasonably equipped for multimedia-based education. However there have been hardly any effort to develop courseware for vocational education in Korea. In this paper, a CAI title for learning basic characteristics of alternating current has been designed and implemented. The developed multimedia-based CAI title has been applied with respect to first grade students at local vocational high schools. A survey after classes shows that CAI could help student feel much comfortable with Basic Electricity course and grasp physical understanding much easily. Accordingly we conclude that classes adopting CAI would be of great help to put education in vocational high schools on the right track.

• Journal of Nutrition and Health
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• v.50 no.2
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• pp.121-132
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• 2017

Purpose: This review was performed to establish a reference intake of water for Korean (KDRI-water) adults in 2015 by examining current knowledge of the relationship between water intake and health and the general status of water intake and loss. We expect that this study will be utilized for further refinement of KDRI-water. Methods: Documents were searched using RISS, NDSL, DBPIA, CINAHL, and Pubmed with the keywords 'water intake, water supply, water ingestion, hydration, dehydration, water balance, and fluid balance'. Results: Water balance is essential for the maintenance of health. Based on this assumption, numerous studies have been performed to investigate the association of water intake with several diseases such as urolithasis, obesity, diabetes, and cancer as well as other health problems, including constipation, cognition, and fetal weight. Effects of water intake for prevention or relief of these health problems vary. Water is supplied to the body by eating foods and drinking liquids such as plain water and beverages. Metabolic water is another source of water input. Water is lost through urine, skin, respiration, and feces. KDRI-water 2015 was set by adequate intake (AI) based on water intake volume, which was the sum of water intakes from foods and fluids reported by the Korea National Health and Nutrition Examination Survey, with extra milk intake of 200 mL. AIs in some age groups were modified considering their estimated energy requirements. Conclusion: Accurate data of water intake is critically important for the establishment of KDRI-water. Therefore, improvement of systems investigating water intake is required, and more studies on the status of water intake and loss in Korean people are needed for definite KDRI-water establishment.