• Solar Energy
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• v.15 no.2
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• pp.25-37
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• 1995

This paper presents an approximate analytical solution to one-dimensional model of the charging process for stratified thermal storage tanks, in which variation of the inlet temperature as well as the momemtum-induced mixing is taken into accout. The mixing is incorporated into the model as a constant-depth perfectly mixed layer above the plug flow region. Based on the superposition principle, the variable inlet temperature is approximated by a number of step functions. Temperature distributions for the thermocline corresponding to three types of interfacial condition arr successfully derived in terms of well-defined functions, so that a linear combination of them constitutes the final solution. Validity and utility of this work is examined through the comparison of the approximate solution with an exact solution available for the case of linearly increasing inlet temperature. With increasing the number of steps, the present solution asymptotically approaches to the exact one. Even with a limited number of steps, the present results favorably agree with those by the exact solution for a wide range of the mixing depth. Also, it is revealed that fewer steps are needed for meaningful predictions as the mixing. depth becomes larger.

• Journal of Korean Theatre Studies Association
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• no.40
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• pp.451-502
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• 2010

The thesis is to look for the method of applying process drama for bilingual education in multicultural society. This purpose can be resolved in three steps: first, to understand the purposes and functions of education changing to multicultural society; second, to survey the need of bilingual education conformed to its purposes and functions; last, to understand the theoretical background of process drama and seek the method of utilizing it to bilingual education. Recently, the Korean society is also changing to multicultural society with international marriages and immigrant workers. But they have difficulties in communicating in Korean, and their children have even the same. Under the basis of multiculturalism wanting peace and mutual respect between cultural groups, they have to be educated in equality. This is why the bilingual education is needed in our society. Process drama, a widely used term for educational drama in Britain, claims its effectiveness for L1, L2 and bilingual education, for the principal medium in drama is language and what drama delivers is related to meaningful human experiences. It is also supported on script theory of linguistic therapy. Kase-Polisini classifies the developmental process of education drama into 1) planning, 2) playing and 3) evaluation. This process can be applied to educational drama for language as well. Rather, educational drama applying to bilingual education has even more availability with the varieties of group organization and subject matter. Conclusively speaking, the group of dual language schools can be organized into 1) mother-tongued group, 2) mother-tongued and L2 group, 3) multilingual group, or 4) L3 group in educational drama activity, as the class generally consist of the mixed multilingual children. And the subject matter can deal with 1) the Korean society and culture, 2) the society and culture of the purposed language country, or 3) the society and culture of the third nations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1427-1435
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• 2010

A mixed finite element model was developed using the classical plate theory to analyze the nonlinear bending of a plate. The appropriate weight functions for the constraints integrated over the domain were determined by the Lagrange multiplier method by using the principle of minimum virtual energy; which provides the constitutive relations between force-like variables and strains. All of detail terms of element wise coefficient matrices and associate tangent matrices to be used in the Newton iterative method are presented. Then, the linear solutions of the current model and those of the traditional displacement model under the SS (simple support) boundary conditions were compared with the existing analytical solution. The post-processed images of the nonlinear results of the force-like variables are presented to show the continuity of the solutions at the joint of the element boundaries. Finally, the converged nonlinear finite element solutions of the current model are compared with those of existing traditional displacement model.

• Journal of Ginseng Research
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• v.28 no.2
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• pp.120-126
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• 2004

Glial cells such as astrocytes and microglial cells are the main source of proinflammatory cytokines and nitric oxide(NO) in the central nervous system, which exert neuroimmune and inflammatory functions and other various neurobiologic effects. Though Panax ginseng C.A. Meyer has been known to strengthen the body's defence mechanisms and also to maintain the homeostasis in the central nervous system, the effects of Panax ginseng on the production of immune and inflammatory mediators have not been studied well in the brain. Therefore, this study was designed to study the effects of ginseng saponins on the production of proinflammatory cytokines and NO in the primary cultures of mixed glial cells. White ginseng saponin, 200-500 $\mu$g/ml, showed significant cytotoxicity after 72 hrs and increased TNF-$\alpha$, IL-$\beta$, and NO production. Lower doses of 50-100 $\mu\textrm{g}$/ml showed little cytotoxicity until 72 hrs and also increased the production of TNF-$\alpha$, IL-1$\beta$, and NO. Triple immune staining showed that white ginseng saponin, 200$\mu\textrm{g}$/ml for 72 ks, induced stellation of astrocytes and iNOS expression exclusively in microglial cells. Taken together, the white ginseng saponin increased the production of proinflammatory cytokines such as TNF-$\alpha$ and IL-1$\beta$, and induced iNOS expression and NO production in mixed glial cell cultures, which may be ascribed to the enhancement of central immune responses and the regulation of inflammatory reactions by Panax ginseng.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.6
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• pp.670-677
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• 2007

The stability of CGAs(colloidal gas aphrons) prepared from non-ionic and ionic surfactants was investigated. Those surfactants were sodium dodecyl sulfate(SDS), Triton X-100, Tween 80 and Quillaja Saponin. The stability of CGAs prepared from single surfactants or mixed surfactants(two components) using a CGA generate. was investigated as functions of temperature, surfactant concentration and stirring time. Saponin among the single surfactants has shown the longest duration time(143 min) and then, Triton X-100, SDS, and Tween 80 were followed by at room temperature. In case of CGAs heated up to $70^{\circ}C$, SDS endured for 116 min but Saponin lasted for only 105 mit which was a considerable reduction of the duration time of CGAs at room temperature. For mixed surfactant pairs, stability of any one pairs stood between the two. That meant no synergic effect for surfactant blending. At the higher temperature, Saponin+Triton X-100 was disclosed to be the lowest, 53 min meanwhile Saponin+SDS was the highest at ambient temperature. The CGAs, initially about 140 ${\mu}m$ in diameter, began to grow right after the agitation to be about 190 ${\mu}m$ owing to coalescence of the bubbles and then became to collapse. When heated, CGAs including Saponin tended to be smaller while the others to be larger. In summary, we found that the stability of CGAs or the duration time was greater for single surfactants and at room temperature rather than for mixed surfactants that caused substantial intermolecular interactions in the CGA structure and at the higher temperature.

• Journal of Intelligence and Information Systems
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• v.29 no.3
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• pp.211-227
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• 2023

Personal service robots, a type of social robot that has emerged with the aging population and technological advancements, are undergoing a transformation centered around technologies that can extend independent living for older adults in their homes. For older adults to accept and use social robot innovations in their daily lives on a long-term basis, it is crucial to have a deeper understanding of user perspectives, contexts, and emotions. This research aims to comprehensively understand older adults by utilizing a mixed-method approach that integrates quantitative and qualitative data. Specifically, we employ the Van Kaam phenomenological methodology to group conversations into nine categories based on emotional cues and conversation participants as key variables, using voice conversation records between older adults and social robots. We then personalize the conversations based on frequency and weight, allowing for user segmentation. Additionally, we conduct profiling analysis using demographic data and health indicators obtained from pre-survey questionnaires. Furthermore, based on the analysis of conversations, we perform K-means cluster analysis to classify older adults into three groups and examine their respective characteristics. The proposed model in this study is expected to contribute to the growth of businesses related to understanding users and deriving insights by providing a methodology for segmenting older adult s, which is essential for the future provision of social robots with caregiving functions in everyday life.

• Journal of Korean geriatric psychiatry
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• v.16 no.1
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• pp.24-30
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• 2012

Objectives : The purpose of this study was to compare the efficacy of galantamine treatment, especially attention ability between patients with pure Alzheimer's disease (AD) and Mixed dementia (MD) during a 24-week trial. Methods : A total of 40 patients were recruited for this 24-week study. The effect of galantamine on attention was measured using Seoul Computerized NeuroCognitive Function Test (SCNT) and frontal functions test of Seoul Neuropsychological Screening Battery (SNSB). Patients'activities of daily living using the Seoul-Activities of Daily Living (S-ADL) and the Seoul-Instrumental Activities of Daily Living (S-IADL) ; behavioral symptoms using the Korean version Neuropsychiatric Inventory (K-NPI) were measured at baseline and 24-week. Results : 17 pure AD patients and 23 MD patients were analyzed in this study. Attention as measured by SCNT was not significantly different from baseline after 24 weeks of treatment in both groups. There was no significant difference between two groups in mean change from baseline in the SCNT, S-ADL, S-IADL and K-NPI scores at 24-week. Conclusion : Galantamine showed a therapeutic effect on cognition, activities of daily living, neuropsychiatric symptoms in pure AD and MD. Furthermore, Galantamine may specifically help to maintain attention and it may have positive effects on other cognitive and functional abilities.

• Journal of architectural history
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• v.24 no.4
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• pp.19-28
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• 2015

This study examines the Singapore public housing supplied by Singapore Improvement Trust (SIT) in the 1950s. Focused on the Princess Elizabeth estate and Princess estate of Queenstown, this study surveys their construction backgrounds, site plans, unit plans, architectural designs and meanings. The Princess Elizabeth estate was the model estate for workmen's flats. This estate showed mixed blocks of flats arranged around a large quadrangled open space for children. The Princess estate was a neighborhood of Queenstown, Singapore's the first new town. At this Estate, there were some new architectural occurrences departing from the Tiong Bahru Estate. Those are the appearance of high-rise typology, and the increased specificity in the functions of open spaces. Thus the open space became to get hierarchy, and divided an estate to small neighborhood units. For the SIT, open space is synonymous with the improvement of urban environment. Through the purposeful creation of open space, the SIT intended to solve the problem of sanitation and to make a neighborhood unit which can be pleasant place for regional community.

• ETRI Journal
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• v.22 no.2
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• pp.11-19
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• 2000

If the right and left signals of a binaural sound recording are reproduced through loudspeakers instead of a headphone, they are inevitably mixed during their transmission to the ears of the listener. This degrades the desired realism in the sound reproduction system, which is commonly called 'cross-talk.' A 'cross-talk canceler' that filters binaural signals before they are sent to the sound sources is needed to prevent cross-talk. A cross-talk canceler equalizes the resulting sound around the listener's ears as if the original binaural signal sound is reproduced next to the ears of listener. A cross-talk canceler is also a solution to the problem-how binaural sound is distributed to more than 2 channels that drive sound sources. This paper presents an effective way of building a cross-talk canceler in which geometric information, including locations of the listener and multiple loudspeakers, is divided into angular information and distance information. The presented method makes a database in an off-line way using an adaptive filtering technique and Head Related Transfer Functions. Though the database is mainly concerned about the situation where loudspeakers are located on a standard radius from the listener, it can be used for general radius cases after a distance compensation process, which requires a small amount of computation. Issues related to inverting a system to build a cross-talk canceler are discussed and numerical results explaining the preferred configuration of a sound reproduction system for stereo loudspeakers are presented.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.945-949
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• 2004

These days there are so many scheduling systems or softwares. But only few scheduling systems have succeeded in the market. In spite of powerful engine and functions, those systems have difficulties to be applied in real processes. In real processes, there are various constraints caused by physical or systematical environments of plants. Those constraints are too many to be handled in the system. This problem makes it difficult for the system to represent the details of processes. In order to resolve this problem, we have developed a specialized scheduling system for a target process. The system could be developed by the experts for target process and researchers for scheduling. In this study, a scheduling system for PVC process has been developed as an MILP (Mixed integer linear programming) model and coded in $Fortran^{TM}$. The scheduling system has been applied to two processes, which have different characteristics. Simulation results indicate that the profit of the target process can be increased by about 5% by implementing the scheduling system.