• Journal of KIISE:Databases
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• v.28 no.4
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• pp.529-544
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• 2001

Prefetching is an effective method to minimize the number of roundtrips between the client and the server in database management systems. In this paper we propose new notions of the type-level access pattern and the type-level access locality and developed an efficient prefetchin policy based on the notions. The type-level access patterns is a sequence of attributes that are referenced in accessing the objects: the type-level access locality a phenomenon that regular and repetitive type-level access patterns exist. Existing prefetching methods are based on object-level or page-level access patterns, which consist of object0ids of page-ids of the objects accessed. However, the drawback of these methods is that they work only when exactly the same objects or pages are accessed repeatedly. In contrast, even though the same objects are not accessed repeatedly, our technique effectively prefetches objects if the same attributes are referenced repeatedly, i,e of there is type-level access locality. Many navigational applications in Object-Relational Database Management System(ORDBMs) have type-level access locality. Therefore our technique can be employed in ORDBMs to effectively reduce the number of roundtrips thereby significantly enhancing the performance. We have conducted extensive experiments in a prototype ORDBMS to show the effectiveness of our algorithm. Experimental results using the 007 benchmark and a real GIS application show that our technique provides orders of magnitude improvements in the roundtrips and several factors of improvements in overall performance over on-demand fetching and context-based prefetching, which a state-of the art prefetching method. These results indicate that our approach significantly and is a practical method that can be implemented in commercial ORDMSs.

• Journal of Nutrition and Health
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• v.50 no.3
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• pp.284-293
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• 2017

Purpose: This study was conducted to examine the behavioral intentions of breastfeeding in single women using the theory of planned behavior. Methods: The questionnaires were distributed to 350 single women in her 20~30s, and 316 respondents were analyzed by descriptive statistics, Spearman's correlation, and multiple regression analysis. Results: The subjects showed strong intentions and favorable attitudes toward breastfeeding. The subjects were more favorably influenced by their mothers, siblings, friends, and coworkers who previously experienced breastfeeding than ones with no breastfeeding experiences. There were significant correlations between breastfeeding intention and attitudes (r = 0.321, p < 0.0001), subjective norms (r = 0.434, p < 0.0001), and perceived control (r = 0.307, p < 0.0001). However, regression analysis with two different age groups revealed that subjective norms (p < 0.0001) and perceived control (p < 0.001) contributed to the model of explaining breastfeeding intentions in subjects who were 25 years old or younger, whereas attitudes did not. In addition, subjects who were more than 25 years old showed that attitudes (p < 0.003) and subjective norms (p = 0.002) contributed to the model of explaining breastfeeding intentions while perceived control (p < 0.070) showed less contribution. Conclusion: These results suggest that the theory of planned behavior can be a useful tool to increase the rate of breastfeeding intentions in single women when designing educational materials, which requires consideration of age differences.

• Proceedings of the Korean DIstribution Association Conference
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• 2005.11a
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• pp.29-51
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• 2005

Brands are important in the consumer market. They are the interface between consumers and the company, consumers may develop loyalty to brands. also, The late development of industrial marketing explains the near absence of research on Brand Equity in business to business. With recent change, industrial companies have shifted from a production focus to a customer focus. industrial brand is fast developing. The basic purpose of this study is to investigate industrial brand trust and loyalty affecting the Result of business relationship between industrial buyers and suppliers. Factors hypothesized to influence trust in a brand include a number of brand characteristics, company characteristics and consumer-brand characteristics. This research presented a comprehensive constructive model consisting of components of industrial brand trust and loyalty, and then propose the research model base on prior researches and studies about relationships among components of industrial brand loyalty. Data were gathered from respondents who work in industrial buying center. For this study, Data were analyzed by SPSS 10.0 and AMOS 4.0. The results of this research analysis were as fallow. Industrial brand trust and loyalty were positively related with a number of industrial brand characteristics, supplier characteristics and buyer-brand characteristics. relationship commitment. This research newly proposed the concept of 'industrial brand trust and loyalty affecting the Result of business relationship between industrial buyers and suppliers'

• Journal of Distribution Science
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• v.4 no.2
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• pp.81-106
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• 2006

The value of Its visitors is very important factors on selection of a Spa & Resort. The first detailed purpose of this paper is to analyse the differences of select behaviors of a Spa & Resort according to the types of values of the visitors. The second aim is to conduct a research on the characters of select behaviors of the visitors. The third aim is to analyse the degree of satisfaction of the visitors, re-visitation and the intention of recommendation. The fourth purpose is to provide useful materials on analysis about the values of the visitors at various Spa & Resorts and to trigger dramatic effect of recuperation, relaxation with its visitor's needs met, the maximum of hotel's management profit at Spa & Resort's area and programs to activate the region's economy. Factor Analsis Routine of SPSS Windows Version 10.0 was applied to accomplish the issues of the study. The Applied analysis by research process are as follows; This paper applied Frequency analysis to figure out interviewee's demographic characters and various using types of the visitors, using their experience of visiting, Select influence, Visiting period, Accommodation they use, Accompanyist, Costs, Season, Transportation, The necessary time. This paper showed important correlation between the visitors' select attributes and behaviors after using it, between their personal value and behaviors after using it, between their individual value, motive of use and their select behavior of destinations. In accordance with it, Managers or developer of a Spa & Resort should make a plan after a sufficient review of the visitors' individual value. The visitor's value is changing continuously according to the change of spatial, occasional environment and should be assessed by those changes.

• Korean Journal of Hospice Care
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• v.8 no.1
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• pp.29-48
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• 2008

Purpose: The purpose of this study was to provide the basic information on the improvement plan by identifying the role accomplishment and job satisfaction of the hospice nurses and analyzing the factors that impact such role accomplishment and job satisfaction. Methods: The data was collected of 189 hospice nurses who have been working more than 6 months in 56 hospice programs registered in Korea Hospice Association and Korean Catholic Hospice Association from October to November, 2007 by structured questionnaire which was developed by Ryu(1979), based on the Riehl's nursing role and the research of Choe(2005) on the role of hospice nurse. Results: The role accomplishment and job satisfaction of the study subject were 3.53 point and 3.39 point, respectively. The roles of hospice nurses were accomplished by the order of advocator, nursing care provider, coordinator (cooperation), educator, quality manager, counsellor, administrator, and researcher. The job satisfaction of the hospice nurses was shown highest in the satisfaction of professional status, followed by the satisfaction of the interaction, satisfaction of the task itself, satisfaction of the administrative aspect, satisfaction of the autonomous, and the lowest in the satisfaction of the pay. The role accomplishment of the subjects according to their socio-demographic and job characteristics was found to have a significant difference by their age, marriage status, academic background, and position. It also has a significant difference by whether they play role of coordinator, whether they took whole responsibility as hospice, working experience as hospice/palliative nurse, and the level of hospice/palliative nursing training(p<.05). In the study of job satisfaction of the subjects according to their socio-demographic and job characteristics, the job satisfaction was found to have a significant difference by the increase of age, the number of duties consisting the hospice team, whether they play role of coordinator, whether they take whole responsibility as hospice, the level of hospice/palliative nursing training, and whether they wish to work for as long as possible(p<.05). The role accomplishment and the job satisfaction of the subjects showed a statistically significant positive correlation. (r=.541, p<.01) Conclusion: Raised saiary will be increased hospice nurse's job satisfaction. And we suggest a repetitive study using the identical tool to the equally extracted subjects with same representativeness of each hospice/palliative institute type. For the expanded role and enhanced professional standard of hospice nurses, we also suggest a study on the improvement plan to enhance the roles of researcher and administrator.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.682-688
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• 2012

This study investigates the stressors of dental hygienists and student hygienists during the bedside training by the medical center type. The survey is based on some dental hygienists who are working for dental college hospitals, general hospitals, dental hospitals and dental clinics in Seoul and Gyeonggi area which the Clinical Practice of dental hygienics students is under way in. Included are the students who are studying dental hygienics at Kyungbok University and have taken the bedside training in dental college hospitals, general hospitals, dental hospitals and dental clinics. A statistical analysis shows the following results using SPSS program. By medical center type, dental hygienists described the clinical practice of students as relatively satisfying. It also found that there is a positive correlation between stress zones, and they feel most stressed in the "Role and Activity" zone. Student hygienists felt relatively satisfied with the bedside training, and there is a positive correlation between stress zones except "Practice". It found students, who have taken the bedside training in all types of medical centers except dental clinics, felt most stressed in "Environment". It also found that students who have taken the bedside training in dental clinics felt most stressed in "Role and Activity". In conclusion, most of the dental hygienists are satisfied with students' clinical practice by pattern of hospital. Positive correlation was shown between stress factors. Behavior and attitude and ideal and value are high in stress in college dental hospitals, role and activity and treatment fields are high in stress in dental hospital, and interpersonal relationships are high in stress in dental clinics.

• Journal of the Korean Society of Child Welfare
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• no.36
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• pp.165-196
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• 2011

With the increasing concerns of victimization of school violence, this paper is intended to present a pioneering study on the victims' conscientization which may result from their own experience of school violence by peers. The predominant concern of the study consists in: (1) the direct effects of individuals' perception toward violence in general, non-assertiveness, school violence experience by peers, and prosocial behavioral tendency on the individual conscientization of school violence problems; (2) the indirect effects of both individual prosocial behavioral tendency and perceptions toward violence through non-assertiveness on individual conscientization of school violence problems;(3) the sexual differences of the five latent variables(perceptions toward violence in general, non-assertiveness, prosocial behavioral tendency, school violence experience by peers, and conscientization of school violence problems; (4) the sexual differences of both direct and indirect correlates on conscientization of school violence problems. Research is based on a survey conducted with 526 adolescents (268 males and 258 females) from 16 middle schools located in different districts of the city of Pohang. In order to address the research questions, structural equation models on adolescents' conscientization of school violence are explored. A variety of tests are conducted (configural invariance, metric invariance and structural invariance, intercept invariance, critical ratio for difference test, multi-group analysis, latent mean analysis including Cohen's effect test). The major findings of the study support the significance of both direct effects and indirect effects of the four latent factors(perceptions of violence in general, non-assertiveness, prosocial behavioral tendency, school violence experience by peers). The individual prosocial behavioral tendency has a positive mediating effect on the enhancement of individual conscientization toward school violence problems. However, we fail to find the direct positive effect of individual violence experience on the conscientization of school violence problems. In conclusion, a range of practical implications for social workers and other related professionals who are engaged in helping out the adolescents with school violence by peers are suggested based on the study findings.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.665-679
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• 2019

Mesoscale soil moisture measurement from the promising Cosmic-Ray Neutron Probe (CRNP) is expected to bridge the gap between large scale microwave remote sensing and point-based in-situ soil moisture observations. Traditional calibration based on $N_0$ method is used to convert neutron intensity measured at the CRNP to field scale soil moisture. However, the static calibration parameter $N_0$ used in traditional technique is insufficient to quantify long term soil moisture variation and easily influenced by different time-variant factors, contributing to the high uncertainties in CRNP soil moisture product. Consequently, in this study, we proposed a modified traditional calibration method, so-called Dynamic-$N_0$ method, which take into account the temporal variation of $N_0$ to improve the CRNP based soil moisture estimation. In particular, a nonlinear regression method has been developed to directly estimate the time series of $N_0$ data from the corrected neutron intensity. The $N_0$ time series were then reapplied to generate the soil moisture. We evaluated the performance of Dynamic-$N_0$ method for soil moisture estimation compared with the traditional one by using a weighted in-situ soil moisture product. The results indicated that Dynamic-$N_0$ method outperformed the traditional calibration technique, where correlation coefficient increased from 0.70 to 0.72 and RMSE and bias reduced from 0.036 to 0.026 and -0.006 to $-0.001m^3m^{-3}$. Superior performance of the Dynamic-$N_0$ calibration method revealed that the temporal variability of $N_0$ was caused by hydrogen pools surrounding the CRNP. Although several uncertainty sources contributed to the variation of $N_0$ were not fully identified, this proposed calibration method gave a new insight to improve field scale soil moisture estimation from the CRNP.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.1-2
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• 2011

Hybrid rockets have lately attracted attention as a strong candidate of small, low cost, safe and reliable launch vehicles. A significant topic is that the first commercially sponsored space ship, SpaceShipOne vehicle chose a hybrid rocket. The main factors for the choice were safety of operation, system cost, quick turnaround, and thrust termination. In Japan, five universities including Hokkaido University and three private companies organized "Hybrid Rocket Research Group" from 1998 to 2002. Their main purpose was to downsize the cost and scale of rocket experiments. In 2002, UNISEC (University Space Engineering Consortium) and HASTIC (Hokkaido Aerospace Science and Technology Incubation Center) took over the educational and R&D rocket activities respectively and the research group dissolved. In 2008, JAXA/ISAS and eleven universities formed "Hybrid Rocket Research Working Group" as a subcommittee of the Steering Committee for Space Engineering in ISAS. Their goal is to demonstrate technical feasibility of lowcost and high frequency launches of nano/micro satellites into sun-synchronous orbits. Hybrid rockets use a combination of solid and liquid propellants. Usually the fuel is in a solid phase. A serious problem of hybrid rockets is the low regression rate of the solid fuel. In single port hybrids the low regression rate below 1 mm/s causes large L/D exceeding a hundred and small fuel loading ratio falling below 0.3. Multi-port hybrids are a typical solution to solve this problem. However, this solution is not the mainstream in Japan. Another approach is to use high regression rate fuels. For example, a fuel regression rate of 4 mm/s decreases L/D to around 10 and increases the loading ratio to around 0.75. Liquefying fuels such as paraffins are strong candidates for high regression fuels and subject of active research in Japan too. Nakagawa et al. in Tokai University employed EVA (Ethylene Vinyl Acetate) to modify viscosity of paraffin based fuels and investigated the effect of viscosity on regression rates. Wada et al. in Akita University employed LTP (Low melting ThermoPlastic) as another candidate of liquefying fuels and demonstrated high regression rates comparable to paraffin fuels. Hori et al. in JAXA/ISAS employed glycidylazide-poly(ethylene glycol) (GAP-PEG) copolymers as high regression rate fuels and modified the combustion characteristics by changing the PEG mixing ratio. Regression rate improvement by changing internal ballistics is another stream of research. The author proposed a new fuel configuration named "CAMUI" in 1998. CAMUI comes from an abbreviation of "cascaded multistage impinging-jet" meaning the distinctive flow field. A CAMUI type fuel grain consists of several cylindrical fuel blocks with two ports in axial direction. The port alignment shifts 90 degrees with each other to make jets out of ports impinge on the upstream end face of the downstream fuel block, resulting in intense heat transfer to the fuel. Yuasa et al. in Tokyo Metropolitan University employed swirling injection method and improved regression rates more than three times higher. However, regression rate distribution along the axis is not uniform due to the decay of the swirl strength. Aso et al. in Kyushu University employed multi-swirl injection to solve this problem. Combinations of swirling injection and paraffin based fuel have been tried and some results show very high regression rates exceeding ten times of conventional one. High fuel regression rates by new fuel, new internal ballistics, or combination of them require faster fuel-oxidizer mixing to maintain combustion efficiency. Nakagawa et al. succeeded to improve combustion efficiency of a paraffin-based fuel from 77% to 96% by a baffle plate. Another effective approach some researchers are trying is to use an aft-chamber to increase residence time. Better understanding of the new flow fields is necessary to reveal basic mechanisms of regression enhancement. Yuasa et al. visualized the combustion field in a swirling injection type motor. Nakagawa et al. observed boundary layer combustion of wax-based fuels. To understand detailed flow structures in swirling flow type hybrids, Sawada et al. (Tohoku Univ.), Teramoto et al. (Univ. of Tokyo), Shimada et al. (ISAS), and Tsuboi et al. (Kyushu Inst. Tech.) are trying to simulate the flow field numerically. Main challenges are turbulent reaction, stiffness due to low Mach number flow, fuel regression model, and other non-steady phenomena. Oshima et al. in Hokkaido University simulated CAMUI type flow fields and discussed correspondence relation between regression distribution of a burning surface and the vortex structure over the surface.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1234-1268
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• 2004

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2002 and 2003 has been carried out. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment/design. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation in diverse facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat transfer, humidity was also interesting to promote comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing research topics. Well developed CFD technologies were widely applied for analysis and design of various facilities and their systems. (2) Heat transfer characteristics of enhanced finned tube heat exchangers and heat sinks were extensively investigated. Experimental studies on the boiling heat transfer, vortex generators, fluidized bed heat exchangers, and frosting and defrosting characteristics were also conducted. In addition, the numerical simulations on various heat exchangers were performed and reported to show heat transfer characteristics and performance of the heat exchanger. (3) A review of the recent studies shows that the performance analysis of heat pump have been made by various simulations and experiments. Progresses have been made specifically on the multi-type heat pump systems and other heat pump systems in which exhaust energy is utilized. The performance characteristics of heat pipe have been studied numerically and experimentally, which proves the validity of the developed simulation programs. The effect of various factors on the heat pipe performance has also been examined. Studies of the ice storage system have been focused on the operational characteristics of the system and on the basics of thermal storage materials. Researches into the phase change have been carried out steadily. Several papers deal with the cycle analysis of a few thermodynamic systems which are very useful in the field of air-conditioning and refrigeration. (4) Recent studies on refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement when new alternative refrigerants are applied. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and new alternative refrigerants including natural refrigerants. Efficiency of various compressors and performance of new expansion devices are also dealt with for better design of refrigeration/air conditioning system. In addition to the studies related with thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out. It should be noted that the researches on two-phase flow are constantly carried out. (5) A review of the recent studies on absorption refrigeration system indicates that heat and mass transfer enhancement is the key factor in improving the system performance. Various experiments have been carried out and diverse simulation models have been presented. Study on the small scale absorption refrigeration system draws a new attention. Cooling tower was also the research object in the respect of enhancement its efficiency, and performance analysis and optimization was carried out. (6) Based on a review of recent studies on indoor thermal environment and building service systems, it is noticed that research issues have mainly focused on several innovative systems such as personal environmental modules, air-barrier type perimeterless system with UFAC, radiant floor cooling system, etc. New approaches are highlighted for improving indoor environmental conditions and minimizing energy consumption, various activities of building energy management and cost-benefit analysis for economic evaluation.