• Resources Recycling
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• v.3 no.2
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• pp.28-34
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• 1994

A part of used cables, such as electric and communication cables has already been recycled by using simple processing methods. However, it has been found that the main problems in recycling of the used cables are insufficient treatment of fine stranded wires and low recovery of copper by air separation process. It has been shown that copper can be effectively separated from the PE using a solvent treatment method. In the present study, the used communication wires having diameter of 0.4 mm are treated in the mixing solution of toluene and water at $86^{\circ}C$ for about 10 minutes. In the solvent treatment, the copper wires recovered have 10~15mm length, which are much longer than that of 1~2mm length copper wires recovered by air table concentration method used in current recycling plants. The process consisting of cutting, air separation and electrostatic separation would be recommendable for the treatment of mixed cables. In this investigation, fine copper powders can also efficiently be recovered from insulation materials using electrostatic separator at the conditions of 20~50RPM roller speed and 15~30KV high DC power.

• Health Policy and Management
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• v.12 no.4
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• pp.91-113
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• 2002

We report and analyze the Korean physicians' recent general strike over the implementation of the Separation of Prescribing and Dispensing Practice (SPDP) in which more than 18,000 private clinics and 280 hospitals participated. Utilizing game-theoretic models of bargaining we explain why the Korean physicians were so successful in organizing intense collective action against the government and securing very favorable policy outcomes. In particular, we highlight the role of distributional conflict among social actors in shaping the details of institutional reform. The introduction of the SPDP was a necessary first step in the overall reform of health care system in Korea. However, the SPDP was perceived to be a serious threat to the economic viability of their profession by the vast majority of Korean physicians who had long been relied on the profits from selling medicines to compensate for the loss of income due to the low service fee under the previous health care system. The strong political coalition among heterogeneous physicians enabled them to organize an intense form of collective action, the general strike. Thus, physicians were successful not only in dragging the government to a bargaining table, but also winning in the bargaining and securing an outcome vastly favorable to them. On the other hand, the lack of an overall reform plan in the health care policy area, especially the finance of the National Health Insurance and the need for maintaining an image as a successful reform initiator, motivated the government to reach a quick resolution with the striking physicians.

• Journal of the Korean Geotechnical Society
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• v.27 no.5
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• pp.85-92
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• 2011

The dynamic behavior of piles becomes very complex due to soil-pile dynamic interaction, soil non-linearity, resonance phenomena of soil-pile system and so on. Therefore, the proper numerical simulation of the pile behavior needs much effort and calculation time. In this research, a new modeling method, which can be applied to the conventional finite difference analysis program FLAC 3D, was developed to reduce the calculation time. The soil domain in this method is divided into a near-field region and a far-field region, which is not influenced by the soil-pile dynamic interaction. Then, the ground motion of the far-field is applied to the boundaries of the near-field instead of modeling the far-field region as finite meshes. In addition, the soil non-linearity behavior is modeled by using the hysteretic damping model, which determines the soil tangent modulus as a function of shear strain and the interface element was applied to simulate the separation and slip between the soil and pile. The proposed method reduced the calculation time by as much as one third compared with a usual modeling method and maintained the accuracy of the calculated results. The calculated results by the proposed method showed a good agreement with the prototype pile behavior, which was obtained by applying a similitude law to the 1-g shaking table test results.

• Restorative Dentistry and Endodontics
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• v.12 no.2
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• pp.45-53
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• 1987

The purpose of this study was to evaluate the tensile bond strength between composite resin and the human enamel. Three composite resin systems, two chemical (Clearfil Posterior, and Clearfil Posterior-3) and one light cure (Photo Clearfil-A), used with and without an intermediate resin (clearfil bonding agent), were evaluated under different amounts of load (10g, 200g and 200g for a moment) for in vitro tensile bond strength to acid-eched human enamel. Clinically intact buccal or lingual surfaces of 144 freshly extracted human permanent molars, embedded in acrylic were flattened with No #600 carborundum discs. Samples were randomly assigned to the different materials and treatments using a table of random numbers. Eight samples were thus prepared for each group(Table 2) these surfaces were etched with an acid etchant (Kurarey Co. Japan) in a mode of etching for 30 seconds, washing for 15 seconds, and drying for 30-seconds. During the polymerization of composite resin on the acid-etched enamel surfaces with and without bonding agent 10-gram, 200 gram and temporary 200 gram of load were applied. The specimens were stored in 50% relation humidity at $37^{\circ}C$ for 24 hours before testing. An universal Testing machine (Intesco model No. 2010, Tokyo, Japan) was used to apply tensile loads in the vertical directed (fig 5), and the force required for separation was recorded with a cross head speed of 0.25 mm/min and 20 kg in full scale. The results were as follow: 1. The tensile bond strength was much greater in applying a bonding agent than in not doing that. 2. The tensile bond strength of chemical cure composite resin was higher than that of light cure composite resin with applying on bonding agent on the acid-etched enamel. 3. In case of not applying a bonding agents on the acid-etching enamel, the highest tensile bond strength under 200 gram of load was measured in light cure composite resin. 4. The tensile bond strength under 200-gram of load has no relation with applying the bonding agent. 5. Under the load of 10-gram, There was significant difference in tensile bond strength as applying the bonding agent.

• Journal of KIISE
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• v.43 no.12
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• pp.1404-1411
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• 2016

Network virtualization is a technique that abstracts the physical network to provide multiple virtual networks to users. Virtualized network has the advantage to offer flexible services and improve resource utilization. In SDN architecture, network hypervisor serves to virtualize the network through address virtualization, topology virtualization and policy virtualization. Among them, address virtualization refers to the technique that provides an independent address space for each virtual network. Previous work divided the physical address space, and assigned an individual division to each virtual network. Each virtual address is then mapped one-to-one to a physical address. However, this approach requires a lot of flow entries, thus making it disadvantageous. Since SDN switches use TCAM (Ternary Contents Addressable Memory) for the flow table, it is very important to reduce the number of flow entries in the aspect of cost and scalability. In this paper, we propose a LISP based address virtualization, which separates address spaces for the physical and virtual addresses and transmits packet through tunneling, in order to resolve the limitation of the previous studies. By implementing a prototype, we show that the proposed scheme provides better scalability.

• Journal of Korea Water Resources Association
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• v.38 no.7 s.156
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• pp.517-526
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• 2005

In Korea, the methods of estimating groundwater recharge can categorized into two groups. One is baseflow separation method by means of groundurater recession curve, the other is water level fluctuation method by using the data from groundwater monitoring wells. Baseflow separation method is based on annual recharge and lumped concept, and water-table fluctuation method is largely dependent on monitoring wells rather than water budget in watershed. However, groundwater recharge rate shows the spatial-temporal variability due to climatic condition, land use and hydrogeological heterogeneity, these methods have various limits to deal with these characteristics. For this purpose, the method of estimating daily recharge rate with spatial variability based on distributed rainfall-runoff model is suggested in this study. Instead of representative recharge rate of large watershed, the subdivided recharge rate with heterogeneous characteristics can be computed in daily base. The estimated daily recharge rate is an advanced quantity reflecting the heterogeneity of hydrogeology, climatic condition, land use as well as physical behaviour of water in soil layers. Therefore, the newly suggested method could be expected to enhance existing methods.

• Journal of Internet of Things and Convergence
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• v.2 no.2
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• pp.37-49
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• 2016

An IP address is used as a host identifier and a locator to bind hosts and applications to their location in existing Internet. Several protocols are proposed to eliminate this binding. Most of these protocols use IPv6-based host identifiers to maintain compatibility with existing Internet, but these identifiers cannot be handled by standard IPv6 routers because such identifiers are unroutable. Therefore, host identifiers need to be usually converted to locators at hosts, and the standard IPv6 protocol should be modified to interoperate with these protocols. In this paper, we propose a network-based host identifier locator separating scheme in software-defined networking. The proposed scheme separates the underlying network into Host Identity and IP domains in order to directly forward unroutable identifiers. The Host Identity domain operates as an overlaid network over IP domain, and it makes the unroutable identifiers to be routable using distributed hash table based routing strategy. For the evaluation, we compared the proposed scheme with the previous scheme using signaling costs and packet delivery costs. The result shows that the proposed scheme is more suitable in the recent mobile-based environments.

• Tunnel and Underground Space
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• v.19 no.6
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• pp.534-544
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• 2009

The collapse of the underground cavity can cause the abrupt local subsidence of the ground surface. It can be hazardous to the stability of road and building for human activity. Therefore it is necessary to develop reinforcement methods for the filling of the underground cavity. This study was executed to improve the material quality and systems to fill the calcium-aluminate mineral $(C_{12}A_7)$ environmentally, and minimize the loss of filling materials for the steep underground cavity. Filling material which was developed in this study is composed of rapid hardening material and additives. The developed material had rapid hardening and non-separation ability in the water cavity condition, so it made the effective underground dam in the cavity with prevention of material loss when it was poured in the water cavity. Results of heavy metal leaching test for environmental assessment showed that it was environmentally suiTable material for the filling in the mine cavity.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.609-618
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• 2013

Curve number (CN), originally developed, compiled by 'The Natural Resources Conservation Service (NRCS)', and has been widely used throughout the world. However, there is the uncertainty of CN derived from the use of antecedent moisture condition (AMC)/Antecedent Runoff Condition (ARC). As in Korea where nearly 70% covered by mountainous area, it is still not sufficient handbook precedent to guide or support the estimation of AMC/ARC. The failure to develop formal criteria of applying AMC/ ARC will be a gaping profession and results not only in uncertainty of CN estimation in particular, but also in designing appropriate structures in Korea as a whole. This paper is aiming at presenting a critical review of AMC/ARC and deriving a procedure to deal more realistically with event rainfall-runoff over wider variety of initial conditions. Proposed methods have been developed. It is based on modifying estimated runoff to observed runoff with coefficient of determination and then applying different algebraic expression with the verification of AMC by antecedent rainfall table of NEH-1964. The result shows that algebraic expression by Arnold et al. (1996) is the most appropriate for AMC/ARC and the results of AMC/ARC estimation criteria are generally very close to each other. Therefore, this algebraic expression might be applied in South Korea condition properly.

• 한국사회복지학회:학술대회논문집
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• 2004.10a
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• pp.461-492
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• 2004

This study examined the effects of gender, parental support and treatment type on the treatment outcome of adolescent substance abusers. Outcome variable was the successful graduation (or drop) from an Intensive Adolescent Outpatient Program. Adolescents with their parents' support were treated in one of three treatment models (2-weeks Inpatient plus 6 week Intensive Croup-Oriented Outpatient, 8-weeks Intensive Croup-Oriented Outpatient, and 8-weeks Individual-Family Therapy) within a private hospital-affiliated treatment center by managed care practice allowing their own choice (non-random natural assignments). Several hypotheses were tested for main effects by the Log-Linear Analyses for a multi-dimensional contingency table with 440 adolescents (284 boys and 156 girls treated during 1992-l997) from middle-class families with private health insurances. The following results were found. Odds of graduating versus dropping out of the treatment program among : (1) girls were 1.7 times higher than those among boys; (2) adolescents with two-parent were 2.2 times higher than those among adolescents with one-parent ; (3) adolescents with Inpatient plus Outpatient was 1.7 times higher than that of those with Outpatient; (4) adolescents with Individual-Family Therapy was 2.3 times higher than that of those with Outpatient Model. There was no statistically significant outcome difference between the Individual-Family Therapy and the Inpatient plus Outpatient. Implications from the results were discussed. Suggestions were made to improve the treatment components in the areas of gender sensitivity, securing more parental support, alternatives for separation from peer group and integrating new peer groups, and flexibility for the unique needs of individual family. Also, some research questions for future studies were suggested.