• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.94-131
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• 2007

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.94-105
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• 2009

Black locust (Robinia pseudoacacia) stand is representative lowland exotic plantation with low ecological quality and arrested succession in South Korea. To facilitate succession and restore natural vegetation, small canopy gaps (${\sim}57m^2$), which can modify minimally structural variables and reduce restoration related disturbances on stand, was established in the black locust stand, and oak (Quercus serrata) seedlings were introduced in the gap. Two types of varying levels were introduced for gap creation; cutting (C) and girdling (G) on canopies. Understory removal (CU and GU) treatment was applied as subtypes of structural modification. Growth (diameter, height and leaf area) of target species and responses (species composition, diversity and coverage) of understory community were monitored during study years (2007~2008). Canopy openness was different significantly among treatments but not for light availability. Based on the result of logistic regression, growth of height and leaf area of seedlings were significant variables on seedling survival. Height and leaf area of seedlings were increased during study years, although radial growth was reduced. During study years, there were no significant differences in species composition and diversity, and total coverage increased about 20%. Increase of resources by gap creation and understory removal likely affect growth of target species. Small gap creation was effective to reduce understory responses in composition and diverstiy. Synthesized, growth of target species and responses of understory community to small canopy gap creation exhibited, in short term, possibility of utilization in alternative forest restoration and management option. Long-term monitoring is necessary to certificate effect of artificial gap creation on forest restoration.

• Journal of Gastric Cancer
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• v.8 no.4
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• pp.232-236
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• 2008

Purpose: Laparoscopic surgery for gastric cancer was introduced in the past decade because it was considered less invasive than open surgery, and this results in less postoperative pain, faster recovery and an improved quality of life. Several studies have demonstrated the safety and feasibility of this procedure. We examined the outcome of performing laparoscopic surgery for gastric cancer over the last two year. Materials and Methods: From April 2004 to December 2006, 329 patients with gastric adenocarcinoma underwent a laparoscopy-assisted distal gastrectomy with lymph node dissection. The data was retrospectively reviewed in terms of the clinicopathologic findings, the perioperative outcomes and the complications. Results: The total patient group was comprised 196 men (59.6%) and 133 women (40.4%). The mean BMI was 23.6 and the mean tumor size was 2.7 cm. The mean number of harvested lymph node was 22.7, and this was 18.6 before 30 cases and 23.1 after 30 cases, and the difference was significant (P=0.02). The mean operation time was 180.9 min, and this was than 287.9 min before 30 cases and 170.2 min after 30 cases. After 30 cases, there was a significant improvement of the operation time (P<0.01). The mean incision length after 30 cases was shorter than that before 30 cases (P<0.01). Postoperative complications occurred in 24 (7.3%) of 329 patients and there was no conversion to open surgery. Conclusion: Even though the LADG was accompanied by a difficult learning curve, we successfully performed 329 LADG procedures over the past 2 years and we believe that LADG is a safe, feasible operation for treating most early gastric cancers (EGC).

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.172-180
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• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

• 대한공업교육학회지
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• v.41 no.1
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• pp.128-146
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• 2016

The purpose of this study was to provide a basic research data for increasing the quality of 'creative engineering design' lesson and the teaching learning capability of high school teachers by analyzing the teaching learning management status and improvement plan of 'technology home economics subject' lesson for high school teachers. In order to investigate the teaching learning management status, the survey questionnaires from 63 teachers were collected from high school teachers who teach technology home economics subject currently and analyzed by statistical program SPSS 20. The main results of this study were as follows: First, for the contents of 'creative engineering design' lesson, the highest mean of response was 'creative thinking method'(M=4.22). In the learning activities, the teachers perceived the importance of the 'idea concept' highly. Second, in the management of 'creative engineering design' lesson, the teachers perceived the importance of the secure of tool, material budget, and practice space for the lesson highly. In the teaching capabilities, the teacher perceived the importance of the preparing teaching learning strategy most($$M{\frac{._-}{.}}4.14$$). Third, the teachers preferred to product for making uncomfortable things better in life and the other production outside from the content of textbook. Fourth, in the ratio of practice:theory lesson, they perceived the ratio of 3:7(36.5%), 4:6(25.4%), and 2:8(23.8%) are appropriate. In the assessment, the combination of production, portfolio, and presentation was preferred most. Fifth, there were statistically significant difference in teachers' interest and satisfaction and contents about 'creative engineering design' lesson between groups divided by the existence of practice space, certification held(technology teacher, non technology teacher), etc. Therefore, in order to improve the interest and satisfaction about the 'creative engineering design' lesson, the secure of space for technology practice and material budget were required. In addition, training and seminars program for improving the teaching capability for 'creative engineering design' lesson were required.

• Archives of design research
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• v.18 no.3 s.61
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• pp.5-14
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• 2005

In the past, consumers sought utilitarian and defensive consumption in an attempt to move to a balanced state. However, today's consumers go beyond this to consume more for hedonic and creative reasons if not for sheer pleasure. There is an obvious shift from the type of consumption that satisfies basic desires through the characteristics, convenience and quality of goods and services to an era of 'experiential consumption,' in which consumers pursue distinctive value systems and way of life along with a total 'experience' provided by such goods and services. Such a sign of the times has given birth to the experience design that aims at maximizing the strategic use of experiences in design. Research on this subject is gradually increasing. The research and application peformed even without the proper understanding about the concepts and purposes of experience design, however, is likely to deviate from the true nature in its process or method. Also, they are likely to cause rather than solve problems. Accordingly, this study examined the meaning of experience from a spatial aspect, focusing on areas that recognize the experience as economically valuable, making the most of it substantively. The main concept of experience practical used on-line is enhancement of the usability of a medium by reflecting the experience of users accustomed to both off-line and on-line environments and materializing the environment doser to and more familiar with the users, thus allowing them to comfortably use the medium. This is to allow the users to feel more comfortable. The experience practical used pertaining to off-line is a tool to fulfill the sensitivity of users, with efforts to create new, future-oriented consumer values. This, based on the understanding of consumer behavior, seeks to maximize the consumption experience of consumers by providing a combination of sensual and sensitive experiences as well as to enhance the existing experiences by permitting users to create new, extended experiences from the fixed characteristics of products. Furthermore, it aims to provide consumers with the hedonic experience of play through the joy, fun and uniqueness of alternate experiences.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.86-96
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• 2006

Ecoclimap-1, a new complete surface parameter global database at a 1-km resolution, was previously presented. It is intended to be used to initialize the soil-vegetation- atmosphere transfer schemes in meteorological and climate models. Surface parameters in the Ecoclimap-1 database are provided in the form of a per-class value by an ecoclimatic base map from a simple merging of land cover and climate maps. The principal objective of this ecoclimatic map is to consider intra-class variability of life cycle that the usual land cover map cannot describe. Although the ecoclimatic map considering land cover and climate is used, the intra-class variability was still too high inside some classes. In this study, a new strategy is defined; the idea is to use the information contained in S10 NDVI SPOT/VEGETATION profiles to split a land cover into more homogeneous sub-classes. This utilizes an intra-class unsupervised sub-clustering methodology instead of simple merging. This study was performed to provide a new ecolimatic map over Northeast Asia in the framework of Ecoclimap-2 global database construction for surface parameters. We used the University of Maryland's 1km Global Land Cover Database (UMD) and a climate map to determine the initial number of clusters for intra-class sub-clustering. An unsupervised classification process using six years of NDVI profiles allows the discrimination of different behavior for each land cover class. We checked the spatial coherence of the classes and, if necessary, carried out an aggregation step of the clusters having a similar NDVI time series profile. From the mapping system, 29 ecosystems resulted for the study area. In terms of climate-related studies, this new ecosystem map may be useful as a base map to construct an Ecoclimap-2 database and to improve the surface climatology quality in the climate model.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.6
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• pp.60-71
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• 2014

In this study, on the assumption that the urban park originally is imbued with a public welfare ideology, said public welfare ideology and its characteristics were attended to among the various social roles that the urban park currently fulfills. Aspects of welfare meaning in urban parks were attempted to be identified with the former history of urban parks and the movements of the connections between modern parks and welfare territories. The ideologies, benefits and practices regarding the welfare role that the urban park has played from the past to the present were examined and the backgrounds and contexts within which the welfare ideologies have been expressed in the urban park were examined. In order to examine the implicated public welfare ideologies of the urban park, case studies were conducted to identify how they are expressed and practiced in the present times and the facilitation of these parks and public welfare both in the U.S. and the South Korea. The study results of the cases show that expressions of public welfare in urban parks are composed of more specific and visible programs and strategies in the present times, which are different from the simple proclamatory ways in the past. Particularly, in order to visibly practice a public welfare ideology, many-sided integrated designs are conducted along with various public welfare institutions and programs inside and outside of the urban park. The conclusions from this study are as follows. First, the urban park plays a role as a space to realize public welfare ideology, to create welfare benefits and to realize social welfare. Modern urban parks are used as an indicator to measure the actual conditions of social welfare and are a social environmental commodity that can offer universal benefits to urban residents. Second, many-sided integrated designs are tried along with various public welfare institutions at urban parks, which visibly practice public welfare ideologies in the present. In addition, public welfare institutions greatly influence the consistent development of the resources in the urban park. Third, if the detailed utilization of the regional facilities infrastructure could be brought along with multidimensional approaches about the resources in the urban park, it could be much closer to the lives of residents and could secure a space for increasing resident quality of life.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.6
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• pp.39-49
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• 2014

Unpleasant facilities have been unwelcomed by residents within the region since they are considered to negatively influence the living conditions of the region. Yet recently, a park project within these unpleasant facility areas has begun to improve the negative impression of the region and the satisfaction of local residents has been shown to be very high. Also a park project within unpleasant facilities is found to have significant influence on the community, including resolving conflicts and building mutual friendships among residents by creating pleasant living conditions and improving the quality of life of local residents. The purpose of this study is to investigate how the park project within unpleasant facilities changes the satisfaction level of local residents and affects the sense of community. In order to do so, surveys were given to visitors of Seoul Maru Park, which was turned into a park from a sewage treatment center. According to the analysis result, after the sewage treatment center was recreated as Maru Park, citizen satisfaction was found to be very high. The sense of community that the visitors feel was found to be high in general, but the 'sense of connection and neighbor bonds' turned out to be lower compared to the 'sense of settlement and belonging.' A regression analysis was performed to determine the relative influence of visitor satisfaction on the sense of community. As a result, in the division of 'sense of settlement and belonging,' the satisfaction with ecological health was affected the most, followed by satisfaction with scenic beauty, whereas satisfaction with cleanness had no influence. In the division of 'sense of connection and neighbor bond,' none of the satisfaction with cleanness, ecological health and scenic beauty showed any influence in the analysis. According to the above result, a park project within unpleasant facilities brings a positive influence on the 'sense of settlement and belonging,' yet in order to improve the 'sense of connection and neighbor bond,' which is not influenced by the project, the adequate facilities and activity programs are considered to be necessary to change the residents' of sense of community.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6099-6111
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• 2015

This study was a systematic review and meta-analysis comparing the effects of aquatic exercise and land-based exercise in the treatment of knee osteoarthritis. 7 studies (n=449) met selection and exclusion criteria out of 287 potential studies obtained from the literature search via Ovid-Medline, Cochrane Library CENTRAL, CINAHL, RISS and KISS. The overall risk of bias of selected studies using SIGN (Scottish Intercollegiate Guidelines Network) checklist for randomized controlled trials (RCT) was regarded as low. As a result of meta analysis, Standardized Mean Difference (SMD) for pain was -0.26(95% CI -0.49, -0.03, p=0.03, $I^2=14%$), which implies that aquatic exercise groups had significant less pain than land-based exercise groups. On the other hand, there was no significant difference between aquatic exercise groups and land based exercise groups for flexion Range of Motion (ROM) (-0.12, 95% CI -0.51, 0.27, p=0.53, $I^2=0%$), extension ROM (-0.04, 95% CI -0.55, 0.48, p=0.89, $I^2=43%$), physical function (-0.12, 95% CI -0.44, 0.19, p=0.44, $I^2=0%$), Quality of Life (QOL) (-0.15, 95% CI -0.54, 0.24, p=0.46, $I^2=0%$). This study has some limitations due to few RCTs comparing aquatic exercise groups and land-based exercise groups in the treatment of knee osteoarthritis. Therefore, further RCTs should be conducted along with long-term outcomes.