• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.6
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• pp.797-807
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• 2015

The low-altitude PAC-2 Patriot missile system is the backbone of ROK air defense for intercepting enemy aircraft. Currently there is no missile interceptor which can defend against the relatively high velocity ballistic missile from North Korea which may carry nuclear, biological or chemical warheads. For ballistic missile defense, Korea's air defense systems are being evaluated. In attempting to intercept ballistic missiles at high altitude the most effective means is through a multi-layered missile defense system. The missile defense problem has been studied considering a single interception system or any additional capability. In this study, we seek to establish a mathematical model that's available for multi-layered missile defense and minimize total interception fail probability and proposes a solution based on genetic algorithms. We perform computational tests to evaluate the relative speed and solution of our GA algorithm in comparison with the commercial optimization tool GAMS.

• KDI Journal of Economic Policy
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• v.36 no.1
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• pp.107-126
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• 2014

The core of the neoclassical growth theory is the capital investment. Solow proposed that the diminishing return is key to such growth process in establishing the stability of the equilibrium growth path. This key postulation has critical implications on the sustainable and effective development policies, emphasizing the importance of productivity growth not only for the steady-state growth but also for the transitional growth from capital accumulation. This paper suggests a novel way to test the diminishing return, the backbone assumption of Solow model, and confirms its strong presence using the Penn World Tables version 8.0 data, hence validates Solow's implications on effective development policies.

• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.1
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• pp.41-48
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• 2017

Columns in existing reinforced concrete structures that are designed and constructed without considering seismic loads generally exhibit widely spaced transverse reinforcements without using seismic hooks. Due to the insufficient reinforcement details in columns compared to the reinforcement requirements specified in modern seismic codes, brittle shear failure is likely to occur. This may lead to sudden collapse of entire structure during earthquakes. Adequate retrofit strategy is required for these columns to avoid such catastrophic event. In order to do so, behavior of columns in existing reinforced concrete structures should be accurately predicted through computational analysis. In this study, an analytical model is proposed for accurately simulating the cyclic behavior of shear critical columns. The parameters for backbone, as well as pinching and cyclic deterioration in strength and stiffness are calibrated using test data of column specimens failed by shear.

• Korean Journal of Oriental Medicine
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• v.2 no.1
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• pp.104-128
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• 1996

In the ancient times, the medical practice relied primarily upon human instincts and experiences at the same time, shaman's incantations were widely believed to cure diseases, the workings of evil spirits supposedly. For the period from the Old Chosun through Samhan(三韓), Chinese refugees brought a long medical knowledge and skills of the continent. New Chinese medicine, traditional practices and incantations were generally used at this time. In Samhan, however, the last was the most important, performed by a Chongoon(天君). Medicine and the medical system were arranged by the period of the Three Countries(三國時代). No definite record concerning Koguryo remains now. As for Paekje, however, history shows that they set up the system under the Chinese influence, assigning medical posts such as Euibaksa(醫博士, medical doctor), Chaeyaksa(採藥師, pharmacist), and Jukeumsa(呪禁師, medicine man) within Yakbu(藥部, department of medicine). Scientifically advanced, they sent experts to Japan, giving a tremendous influence on the development of the science in ancient Japan. After the unification of the three countries, Shilla(新羅) had theri own system after the model of Dang(唐). This system of the Unified Shilla was continued down to Koryo(高麗) and became the backbone of the future ones.

• Earthquakes and Structures
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• v.9 no.6
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• pp.1273-1290
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• 2015

JK wall is a shear wall made of lightweight EPS mortar and reinforced with a 3-D galvanized steel mesh, called JK panel, and truss-like stiffeners, called JK stiffeners. Earlier studies have shown that low strength lightweight concrete has the potential to be used in structural elements. In this study, seismic contribution of the JK infill walls surrounded by steel frames is numerically investigated. Adopting a hybrid numerical model, behavior envelop of the wall is derived from the general purpose finite element software, Abaqus. Obtained backbone would be implemented in the professional analytical software, SAP2000, in which through calibrated hysteretic parameters, cyclic behavior of the JK infill can be simulated. Through comparison with earlier experimental results, it turned out that the proposed hybrid modeling can simulate monotonic and cyclic behavior of JK walls with good accuracy. JK infills have a panel-type configuration which their dominant failure mode would be ductile in flexure. Finally technical and economical advantages of the proposed JK infills are assessed for two representative multistory buildings. It is revealed that JK infills can reduce maximum inter-story drifts as well as residual drifts at the expense of minor increase in the developed base shear.

• Elastomers and Composites
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• v.38 no.2
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• pp.157-166
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• 2003

The Edwards-Vilgis slip-link theory and the Kaliske-Heinrich extended tube theory were tested experimentally using published experimental data on networks of natural and isoprene rubber and on polysiloxane networks. All parameters were adjusted to achieve an optimum fit. The data description obtained with the EV theory is not satisfactory and the parameter values tend to lie outside their reasonably expected range. But for the region of low strains, the Kaliske-Heinrich theory offers a satisfactorily accurate data description which is able to serve for practical purposes. Its crosslink term, however, is based on approximations which lead to a questionable prediction and values determined for the exponent in the entanglement term lie outside the range expected by the KH model. Thus, the title question cannot be given a positive answer. Conclusions published earlier that the trapped entanglements contribute both to the crosslink and constraint (entanglement) term are supported by the present data analysis. Experimental equibiaxial data on hydrocarbon networks do not show any maximum on their stretch ratio dependence, contrary to the predictions of molecular theories. The stretch ratio dependences of relative reduced stresses do not sensitively reflect differences in the chemical nature of the chain backbone (hydrocarbon vs. siloxane) and in the crosslinking method (end-linking vs. random crosslinking).

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1043-1046
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• 2009

Human protein tyrosine kinase-6 (PTK6) is a member of the non-receptor protein tyrosine kinase family and it is found in two-thirds of all breast tumors. Very recently, we proposed that the SH3 domain of PTK6 interacts with the linker region (Linker) between the SH2 and kinase domains, proving that the interaction between SH3 domain and Linker plays an important role in auto-inhibition mechanism. Residues from 1 to 191 corresponding region of SH3-SH2-Linker (SH32L) of PTK6 was cloned into the pET32a expression vector with Tobbaco etch virus (TEV) protease enzyme site by sequence homology and 3D structural model. The purified PTK6-SH32L was determined as a monomer conformation in solution. The amide proton resonances in the $^{15}N-^{1}H$ 2D-HSQC spectrum suggest that PTK6-SH32L possesses disordered structural region of the flexible/unstructured linker region. In addition, the backbone amide proton chemical shifts of the SH3 domain in the PTK6-SH32L differ from that of the independent domain, indicating that intra-molecular interaction between SH3 and Linker in the PTK6-SH32L is present.

• Journal of Korean Institute of Industrial Engineers
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• v.31 no.2
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• pp.143-151
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• 2005

Information technology(IT) investment evaluation requires measurements from many perspectives. Except for the case of financial performance, these measurements mostly belong to the qualitative or intangible domain. The problem with IT investment evaluation lies in the fact that it is very difficult to define the qualitative properties against which to measure the performances. This paper addresses the issue of developing the set of performance indices, and defining the structural relationships between them, such that the IT investment evaluation can be done in a systematic, objective and comprehensive manner. We introduce the balanced scorecard strategy map as the backbone reference frame for the generation of performance indices and for the description of the relationships between them. Sample indices for evaluating projects from strategic perspectives are provided with a case example. A step by step follow through of the index generation process has been presented along with the case.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.210-216
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• 2007

The backbone structure of ginsenosides, active ingredients of Panax ginseng, is similar with that of sterol, especially cholesterol. Caenorhabditis elegans (c. elegans) is one of free living nematodes and is well-established animal model for biochemical and genetic studies. C. elegans cannot synthesize de novo cholesterol, although cholesterol is essential requirement for its growth and development. In the present study, we investigated the effects of Korean red ginseng total extract (KRGE), ginseng total saponins (GTS) on life span of C. elegans in cholesterol-deprived and -fed medium. Cholesterol deprivation caused damages on life span of worms throughout F1 to F3 generations. KRGE or GTS supplement to cholesterol-deprived medium restored the life span of worms as much as cholesterol alone-fed medium. In study to identify which ginsenosides are responsible for life span restoring effects of KRGE, we found that ginsenoside Rc supplement not only restored life span of worms grown in cholesterol-deprived medium but also prolonged life span of worms grown in cholesterol-fed medium. These results show a possibility that ginsenosides could be utilized by C. elegans as a sterol substitute and further indicate that ginsenoside Rc is the effective component of Korean red ginseng that prolongs the life span of C. elegans.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1401-1406
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• 2013

This study tested the feasibility of observing H/D exchange of intact protein by top-down electron capture dissociation (ECD) mass spectrometry for the investigation of protein structure. Ubiquitin is selected as a model system. Local structural information was obtained from the deuteration levels of c and $z^{\cdot}$ ions generated from ECD. Our results showed that ${\alpha}$-helix region has the lowest deuteration level and the C-terminal fraction containing a highly mobile tail has the highest deuteration level, which correlates well with previous X-Ray and HDX/NMR analyses. We studied site-specific H/D exchange kinetics by monitoring H/D exchange rate of several structural motives of ubiquitin. Two hydrogen bonded ${\beta}$-strands showed similar HDX rates. However, the outer ${\beta}$-strand always has higher deuteration level than the inner ${\beta}$-strand. The HDX rate of the turn structure (residues 8-11) is lower than that of ${\beta}$-strands (residues 1-7 and residues 12-17) it connects. Although isotopic distribution gets broader after H/D exchange which results in a limited number of backbone cleavage sites detected, our results demonstrate that this method can provide valuable detailed structural information of proteins. This approach should also be suitable for the structural investigation of other unknown proteins, protein conformational changes, as well as protein-protein interactions and dynamics.