• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.243-244
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• 2013

Over the past 15 years, several groups have incorporated radio-frequency quadrupole (RFQ) based instruments before the accelerator in accelerator mass spectrometry (AMS) systems for ion-gas interactions at low kinetic energy (＜40 eV). Most AMS systems arebased on a tandem accelerator, which requires negative ions at injection. Typically, AMS sensitivity abundance ratios for radioactive-to-stable isotope are limited to Xr/Xs ＞10^-15, and the range of isotopes that can be analyzed is limited because of theneed to produce rather large negative ion beams and the presence of atomic isobaric interferences after stripping. The potential of using low-kinetic energy ion-gas interactions for isobar suppression before the accelerator has been demonstrated for several negative ion isobar systems with a prototype RFQ system incorporated into the AMS system at IsoTrace Laboratory, Canada (Ontario, Toronto). Requisite for any such RFQ system applied to very rare isotope analysis is large transmission of the analyte ion. This requires proper phase-space matching between the RFQ acceptance and the ion beam phase space (e.g. 35 keV, ${\varphi}3mm$, +-35 mrad), and the ability to control the average ion energy during interactions with the gas. A segmented RFQ instrument is currently being designed at Korea Institute for Science and Technology (한국과학기술연구원, KIST). It will consist of: a) an initial static voltage electrode deceleration region, to lower the ion energy from 35 keV down to ＜40 eV at injection into the first RFQ segment; b) the segmented quadrupole ion-gas interaction region; c) a static voltage electrode re-acceleration region for ion injection into a tandem accelerator. Design considerations and modeling will be discussed. This system should greatly lower the detection limits of the 6 MV AMS system currently being commissioned at KIST. As an example, current detection sensitivity of 41Ca/Ca is limited to the order of 10^-15 while the 41Ca/Ca abundance in modern samples is typically 41Ca/Ca~10^-14 - 10^-15. The major atomic isobaric interference in AMS is 41K. Proof-of-principal work at IsoTrace Lab. has demonstrated that a properly designed system can achieve a relative suppression of KF3-/41CaF3- ＞4 orders of magnitude while maintaining very high transmission of the 41CaF3- ion. This would lower the 41Ca detection limits of the KIST AMS system to at least 41Ca/Ca~10^-19. As Ca is found in bones and shells, this would potentially allow direct dating of valuable anthropological archives and archives relevant to our understanding of the most pronounced climate change events over the past million years that cannot be directly dated with the presently accessible isotopes.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.3
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• pp.70-76
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• 2001

Proper design and improvement of the biofiltration process depend upon quantitative understanding of the kinetic behavior in the biofilter. This study was conducted to evaluate kinetics of biofiltration of gasoline vapor. Filling material of the biofilter was compost. Gas inlet concentration ranged from about $300mg/m^3$ to $7,000mg/m^3$. Gas velocities were 6m/hr and 15m/hr, respectively. At 6m/hr gas velocity, about 60% of gasoline TPH below $3,000mg/m^3$ was removed in the lower quarter part of the biofilter. First order kinetics described well the degradation rate of gasoline TPH with high correlation. First order kinetic removal constant at the gas velocity of 6m/hr was higher than that of 15m/hr from about $300mg/m^3$ to $7,000mg/m^3$. When the inlet concentration was over $3,000mg/m^3$, first order kinetic removal constant at the gas velocity of 6m/hr was over twice that at 15m/hr. In order to obtain over 80% of removal efficiency, gasoline vapor should be injected into the biofilter at concentration below about $2,000mg/m^3$, 100cm filling height and the gas velocity of 6m/hr.

• Journal of Distribution Science
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• v.16 no.9
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• pp.65-77
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• 2018

Purpose - A trading area is very closely related to consumer life. A trading area is a cultural and social space that consumes culture and promotes human relationships as well as an economic space where consumers live their daily lives. In this context, a trading area research should be conducted objectively and empirically because it deals with the activities of consumer's life. The purpose of this study is to identify the intrinsic psychological motivation(push motivation) caused when consumers visit a trading area and to demonstrate how the push motivation for a trading area influence on consumer's flow, satisfaction, revisit intention. Research design, data, and methodology - In order to develop research hypotheses for this study, the development procedures for push motivation scale are as follows; (1) generating initial pool of items based on previous studies, (2) expert judgement to evaluate content and face validity, and (3) assessing convergent and discriminant validity using confirmatory factor analysis. In order to achieve these purposes, online surveys were conducted on frequent or familiar visitors to the trading areas around the Gangnam, Kunkuk University and Hongik University Station. Among the 1,343 questionnaires collected, 1,157 cases were analyzed by using SPSS 22.0 and SmartPLS 3.0 statistical package program, except for 186 responses in which responses were judged to be unfaithful. Results - The push motivation was classified into five sub-dimensions of excitement/stimulus, rest/relaxation, exit/refreshing, knowledge/learning and human relationship promotion as multidimensional and complex factors composed of individual and social-related dimensions. The excitement/stimulus and human relationship promotion of push motivation have positive effects on satisfaction. However, all dimensions of the push motivation have positive effects on flow. And flow has a positive effect on satisfaction and revisit intention. Meanwhile, the mediation test using boostrapping shows that flow plays a full mediating role in the relationship between rest/relaxation, exit/refreshing, knowledge/learning and satisfaction, but a partial mediating rol e between excitement/stimulus, human relationship promotion and satisfaction. Finally, satisfaction plays a partial mediating role between flow and revisit intention. Conclusions - This study shows that the push motivation is multidimensional and compositive depending on the situation of a consumer. In addition, it is found that the human relationship promotion(a social-related motivation) has a much more important effect on flow and satisfaction than other push motivations of individual dimensions. It also shows that satisfaction increases when consumers are being flowed at their visit and degree of revisit intention also grows as satisfaction increases. As implications of this study, a marketer should try to understand consumer's visit motivation at first and then develop factors that increase their flow, satisfaction, revisit intention. It also requires a marketer to approach subjects on a trading area more objectively and empirically based on the psychology and behavior of consumers, in order to establish a proper and efficient strategy on development of a trading area.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.121-133
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• 2013

Defect-free transfer service on the Next-generation wireless network extensive roaming mobile node (MN) to provide efficient mobility management has become very important. MIPv6(Mobility IPv6) is one of mobility management scheme proposed by IETF(Internet Engineering Task Force), and IPv6-based mobility management techniques have been developed in various forms. One of each management techniques, IPv6-based mobility management techniques for PMIPv6 (MIPv6) system to improve the performance of a variety of F-PMIPv6 (Fast Handover for Proxy MIPv6) is proposed. However, the F-PMIPv6 is cannot be excellent than PMIPv6 in all scenarios. Therefor, to select a proper mobility management scheme between PMIPv6 and F-PMIPv6 becomes an interesting issue, for its potenrials in enhancing the capacity and scalability of the system. In this paper, we develop an analytical model to analyze the applicability of PMIPv6 and F-PMIPv6. Based on this model, we design an Secure Smart Mobility Support(SSM) scheme that selects the better alternative between PMIPv6 and F-PMIPv6 for a user according to its changing mobility and service characteristics. When F-PMIPv6 is adopted, SSM chooses the best mobility anchor point and regional size to optimize the system performance. Numerical results illustrate the impact of some key parameters on the applicability of PMIPv6 and F-PMIPv6. Finally, SSM has proven even better result than PMIPv6 and F-PMIPv6.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.495-504
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• 2016

The purpose of this study was conducted to investigate the perception and attitude toward physical restraints among elderly care workers. The subjects were 153 care workers who are working at elderly care facilities within the regions. Data were collected by structured questionnaires. Collected data were analyzed using descriptive statistics, t-test, ANOVA, $Scheff{\acute{e}}$ test and Pearson Correlation Coefficient. The mean score of the perception for physical restraints was 2.83 out of 5, and the mean score of the attitude for the physical restraints was 3.56 out of 5. There was a statistically significant positive correlation between the perception and attitude about physical restraints (r=.31, p<.001). This research has confirmed that it is necessary for care workers to have education about low score items of recognition and attitude about physical restraints. Therefore, we need to develop proper and efficient educational program about use method for physical restraints, and need to develop guideline for adopting physical restraints. Also, we should make efforts and attentions to reduce or abolish physical restraints in order to protect the elderly human rights.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.349-355
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• 2016

This study is about the reuse of bottom ash, which is released as a necessity in thermal power plant. In general, coal-ash are classified as fly-ash, bottom-ash, cinder-ash. Of these, a large amount of fly ash is being recycled as cement substitutes. While, recycling rates of bottom ash are the lowest due to its porosity and high absorption. In this study, the durability of the concrete using bottom ash as a concrete fine aggregate was evaluated. The using level of the bottom ash ranges to step-by-step from 0% to 30%. According to the result of the durability test, regardless of the presence of the bottom ash, freeze-thaw durability could be secured by air entrainment. In case of the resistance to chloride ions penetration, the length change, and the effects on heavy metals, the replacement of bottom ash as fine aggregate was not critical. Although carbonation penetration was higher as the replacement level of bottom ash increased, the experiment showed that it could be possible to use bottom ash as concrete fine aggregate with proper mix design.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.3 s.39
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• pp.171-190
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• 1990

It is the purpose of this study to address how to manage the urban vegitation using the concept of Urban Forestry which is relatively new to Korea. When we consider the Urban Forestry as a science, We should understand it interdisciplinary subject which includes Forestry, Horticulture, Urban Planning, Landscape Design, Landuse Planning, Business and Humanities. It may say that people and tree are the fundermental components of Urban Forestry. So there are two ways of Urban Forestry Applications-How people care for trees and How trees care for People-. For the application, this study places the focus on the monetary valuation, tree inventory system and traditional forestry application to urban forest management. Pubic Relation, Communication, Ordinances and Budget are also mentioned as a part of Urban Forestry Policy. Monetary valuation of trees and forests is very important for the proper cognition of their real value. So that, they may be equated and weighed against conflicting uses which would cause to be removed or severely mutilated. A tree inventory system which is the essential part of urban tree management can provide the pertinent information about the present condition of urban tree resource. It may aid in reducing the subjectivity of tree management decisions and stimulate them to be made rapidly and can help reduce potential municipal liability by identifying serious problems in time for corrective maintenance practices to be applied for the maximize community benefits and minimimize public nuisances or hazards. Managers can derive the information from the inventory and use it for the various management plan. When we see the structure of tree inventory system as one of the data base management system, Computer is the best equipment for the efficient management plan. Public relation and communication is also important factors to care the people for urban vegetation management. Volunteer management system is a good example for the public relation and communication. Those skills are need to develop for using the priceless, valuable human resources. Budget holds the key to the execution of Urban Forestry. Good inventory can provide for efficient budgeting stratiges through it's scientific analysis for the way of maximum benefits and minimum costs. Forest can be play a vital role for the aesthetic improvement and recreation in the city. This study suggests that the traditional sivicultural application not only improve the quality of scenic beauty and recreation but also the products of timber. So it is more needed to study for strong and scientific application to urban forest management.

• The Transactions of the Korea Information Processing Society
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• v.1 no.1
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• pp.114-128
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• 1994

It is very difficult for a nonprofessional programmer in Koera to write a program with very High Level Language such as, V,REFINE, GIST, and SETL, because the semantic primitives of these languages are based on predicate calculus, set, mapping, or testricted natural language. And it takes time to be familiar with these language. In this paper, we suggest a method to reduce such difficulties by programming with the declarative, procedural constructs, and aggregate constructs. And we design and implement an experimental knowledge-based automatic programming system. called HAPS(Hangul Automatic Program System). HAPS, whose input is specification such as Hangul abstract algorithm and datatype or Hangul procedural constructs, and whose output is C program. The method of operation is based on rule-based and program transformation technique, and the problem transformation technique. The problem area is general problem. The control structure of HAPS accepts the program specification, transforms this specification according to the proper rule in the rule-base, and stores the transformed program specification on the global data base. HAPS repeats these procedures until the target C program is fully constructed.

• Resources Recycling
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• v.27 no.2
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• pp.38-47
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• 2018

Integrated gasification combined cycle (IGCC) is a next generation energy production technology that converts coal into syngas with enhanced power generation efficiency and environmental performance. IGCC produces almost coal gasification slag as the solid by-product. IGCC slag is generated about 140,000 tons for a year although recycling of it is still in the early stages. We evaluated the potential of IGCC slag which is generated from a pilot plant in South Korea as an alkali-activated cement. Samples which were activated with the combined activator of sodium silicate solution and caustic soda had an average compressive strength of 4.5 MPa, showing expansion. Expansion of the alkali-activated slag was presumed to be caused by free CaO in the slag, although it was not detected by the ethylene glycol method. Samples that were activated with the combined activator of sodium aluminate and caustic soda had an average compressive strength of 10 MPa. Hydroxy sodalite and $C_3AH_6$ were found to be the new crystalline phases. IGCC slag can be used as an alkali-activated material, but the strength performance should be improved with proper mix design approach to calculate optimum proportions which can alleviate the expansion issue at the same time.

• The KIPS Transactions:PartD
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• v.18D no.5
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• pp.371-384
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• 2011

This paper considers logistics decision support system which deals with transportation mode selection considering transportation and carbon emission cost. Transportation and carbon emission costs vary with the choice of transportation modes and to become competitive companies need to find proper transportation modes for their logistics services. However, due to the restricted capacity of transportation modes, it is difficult to balance transportation and carbon emission costs when designing logistics network including transportation mode choice for each service. Therefore this paper aims to analyze the trade-off relationship between transportation and carbon emission cost in mode selection of intermodal transportation and to provide optimal green logistics strategy. In this paper, the logistics decision support system is designed based on mixed integer programming model. To understand the trade-off relationship of transportation and carbon emission cost, the system is tested with various scenarios including transportation of containers between Seoul and Busan. The analysis results show that, even though sea transportation combined with trucking is competitive in carbon emission per unit distance travelled, the total cost of carbon emission and transportation for the sea transportation may not have competitive advantage over other transportation modes including rail and truck transportation modes. The sea-based intermodal logistics service may induce detours which have negative impacts on the overall carbon emission. The proposed logistics decision support system is expected to play key role in green logistics and supply chain management.