• Korean Journal of Optics and Photonics
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• v.35 no.3
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• pp.107-114
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• 2024

In this study, the feasibility of using the covariance-matrix-adaptation-evolution-strategy (CMA-ES) algorithm in a multichannel coherent-beam-combining (CBC) system was experimentally verified. We constructed a multichannel CBC system utilizing a spatial light modulator (SLM) as a multichannel phase-modulator array, along with a coherent light source at 635 nm, implemented the stochastic-parallel-gradient-descent (SPGD) and CMA-ES algorithms on it, and compared their performances. In particular, we evaluated the characteristics of the CMA-ES and SPGD algorithms in the CBC system in both 16-channel rectangular and 19-channel honeycomb formats. The results of the evaluation showed that the performances of the two algorithms were similar on average, under the given conditions; However, it was verified that under the given conditions the CMA-ES algorithm was able to operate with more stable performance than the SPGD algorithm, as the former had less operational variation with the initial phase setting than the latter. It is emphasized that this study is the first proof-of-principle demonstration of the CMA-ES phase-control algorithm in a multichannel CBC system, to the best of our knowledge, and is expected to be useful for future experimental studies of the effects of additional channel-number increments, or external-phase-noise effects, in multichannel CBC systems based on the CMA-ES phase-control algorithm.

• Journal of Life Science
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• v.31 no.3
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• pp.257-265
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• 2021

Heterotrimeric kinesin-2 is a molecular motor protein of the kinesin superfamily (KIF) that moves along a microtubule plus-end directed motor protein. It consists of three different motor subunits (KIF3A, KIF3B, and KIF3C) and a kinesin-associated protein 3 (KAP3) that form a heterotrimeric complex. Heterotrimeric kinesin-2 interacts with many different binding proteins through the cargo-binding domain of the KIF3s. The activity of heterotrimeric kinesin-2 is regulated to ensure that the cargo is directed to the right place at the right time. How this regulation occurs, however, remains in question. To identify the regulatory proteins for heterotrimeric kinesin-2, we performed yeast two-hybrid screening and found a specific interaction with creatine kinase B (CKB), which is the brain isoform of cytosolic creatine kinase enzyme. CKB bound to the cargo-binding domain of KIF3A but did not interact with the KIF3B, KIF5B, or KAP3 in the yeast two-hybrid assay. The carboxyl (C)-terminal region of CKB is essential for the interaction with KIF3A. Another protein kinase, CaMKIIa, interacted with KIF3A, but GSK3a did not interact with KIF3A in the yeast two-hybrid assay. KIF3A interacted with GST-CKB-C but not with GSK-CKB-N or GST alone. When co-expressed in HEK-293T cells, CKB co-localized with KIF3A and co-immunoprecipitated with KIF3A and KIF3B but not KIF5B. These results suggest that the CKB-KIF3A interaction may regulate the cargo transport of heterotrimeric kinesin-2 under energy-compromised conditions in cells.

• Journal of Life Science
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• v.25 no.5
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• pp.594-600
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• 2015

Protein-protein interactions have a critical role in the regulation of many cellular functions. Postsynaptic density-95/disks large/zonula occludens-1 (PDZ) domain is one of domains that mediate protein-protein interactions. PDZ domains typically bind to the specific motif at the carboxyl (C)-terminal end of partner proteins. Multi-PDZ domain protein 1 (MUPP1), which has 13 PDZ domains, serves a scaffolding function for structure proteins and signaling proteins, but the cellular function of MUPP1 has not been fully elucidated. We used the yeast two-hybrid system to identify proteins that interact with PDZ domains of MUPP1. We found an interaction between MUPP1 and muskelin. Muskelin was recently identified as a GABA_A receptor (GABA_AR) α1 subunit binding protein and known to have a role in receptor endocytosis and degradation. Muskelin bound to the 3^rd PDZ domain, but not to other PDZ domains of MUPP1. The C-terminal end of muskelin was essential for the interaction with MUPP1 in the yeast two-hybrid assay. When co-expressed in HEK-293T cells, muskelin but not the C-terminal deleted muskelin was co-immunoprecipitated with MUPP1. In addition, MUPP1 co-localized with muskelin at the same subcellular region in cells. These findings collectively suggest that MUPP1 or its interacting proteins could modulate GABA_AR trafficking and turnover through the interaction with muskelin.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.4
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• pp.11-20
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• 2009

By using the artificial lightweight aggregate for the natural aggregate depletes and destruction of environment and the application of lightweight concrete in structure, the lightweight concrete is manufactured. The fundamental characteristics by the waterbinder ratio was evaluated. It is suggested the method to control of pre-absorbed water of the lightweight aggregate. Lightweight concrete with pre-absorbed aggregate has similar characteristics compared to normal weight concrete regardless of water-binder ratio. According to the water-binder ratio, the drying condition, and the rebar, the unit mass of the lightweight concrete showed the reduction of 14.6${\sim}$21.0% as the range of 1,668${\sim}$1,998 $kg/m^3$ in comparison to the normal weight concrete. The lightweight aggregate pre-absorbed water showed the deferent evaporation quantity according to the water-binder ratio. As the water-binder ratio is lower, the oven dry vapour water is larger, therefore the internal curing water is increasing. In the same water-binder, comparing the normal concrete the lightweight concrete shows lower compressive strength which is due to the different strength of an aggregate. In the air dry curing, the normal weight concrete has a lower strength improvement effect in w/c 0.3 than the ratio 0.4 and 0.5. However, the strength improvement effect has increasing as the water-binder ratio was low in the light concrete.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.83-90
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• 1999

Although the chitosan has many functional properties due to its cationic amino groups, the application of chitosan in foods is limited by its poor water solubility, bitter taste and astringency. This study was conducted to investigate physicochemical and sensory properties of chitosan hydrolysates in various molecular weights obtained by ultrafiltration after enzymatic hydrolysis. As molecular weight decreased, the solubility of chitosan hydrolysates increased, while the viscosity and emulsion stability decreased. High molecular weight chitosan hydrolysates (>30 kDa) exhibited 800% of fat binding capacity, while low molecular weight ones $(3{\sim}30\;kDa)$ showed 500% of fat binding capacity. Water soluble chitosan hydrolysates exhibited no color differences. Freeze-thaw stability of chitosan hydrolysates was good, without variations among fractions. Cholesterol binding capacity of chitosan hydrolysates was changed from 24% to 36% with increasing molecular weights. From sensory evaluation of chitosan hydrolysates, it was found that bitterness, astringency, chemical flavor and fish flavor of chitosan hydrolysates were very weak.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.299-306
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• 2008

Human pancreatic lipase is a digestive enzyme which is synthesized in pancreas, secreted into small intestine, and there hydrolyze the fat in food. Pancreatic lipase protein composes of catalytic domain and colipase-binding domain. In this research, the gene segments corresponding to total protein, catalytic domain, and co lipase-binding domain were cloned by PCR method, inserted into an expression vector, and then used to transform Escherichia coli BL21 (DE3). The recombinant proteins produced were purified and injected intramuscularly three times into laying hens. The egg yolk antibodies (IgY) were obtained from the egg yolks and tested for their antibody titer. Among three IgY, the IgY against colipase-binding domain showed the highest antibody titer. All three IgY had inhibitory effects on the porcine pancreatic lipase. Among them, the IgY against colipase-binding domain showed the highest inhibition effects. The fat diet with corn oil and IgY was administrated to the experimental rats and their blood compositions were examined with time course. The triglyceride concentration of treated rats was decrease meaningfully when compared with those of control rats. This suggested that the IgY against colipase-binding domain antigen inhibited pancreatic lipase in vivo.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1072-1080
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• 2005

The extraction characteristics of heavy metals(HM) from a contaminated soil at existing lead smelters were investigated with ethylene diamine tetraacetic acid(EDTA), citrate and HCl as washing solutions. EDTA was more effective for Pb than for other heavy metals. As the mol ratio of EDTA/HM increased, the removal efficiency of heavy metals became higher. When the mol ratio of EDTA/HM approached to 6.5, it removed Pb most effectively. Citrate was effective especially in extracting Zn. The removal efficiency of HCl was comparatively high in almost all heavy metals, and at 0.3N concentration it was the highest. After soil washing process by the use of EDTA, the great part of exchangeable fractions and most of heavy metals of weakly adsorbed like carbonate fraction were extracted. For washing with citrate and HCl, four heavy metals showed the similar exchange of chemical partitioning and the exchangeable fractions of Pb which has weakly adsorbed to soil were more increased than before the process. As removal efficiency of citrate washing process depends upon the distribution of non-detrital fractions, so it can be contended that only the amount of non-detrital fractions could be removed from all the heavy metal content. EDTA and HCl could remove most of non-residual fractions in all heavy metals except Zn. As a result of EDTA washing, toxicity characteristic leaching procedure(TCLP) concentration of the processed soil met the USEPA Pb limit of 5.0 mg/L.

• Korean Journal of Social Welfare
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• v.69 no.1
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• pp.103-123
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• 2017

This article examines the existing literature on the intersection of care and migration in Europe and the potential contributions of the Korean case. The paper reviews the three bodies of research: care, migration and their intersections. When defined as social reproductive labour, the concept of care not only captures individual/family level of experiences but it can also be an effective tool to analyse the diversity of the welfare state and the path of its evolution. Furthermore, in the context of globalisation and international migration, the concept of care can help overcome so-called 'the methodological nationalism' in the welfare state research. Accumulated evidence shows that only by applying a transnational perspective to the relationship between such social realities as class, gender and race, can we properly examine the dynamics of care distribution. Existing care-migration nexus research has found a widely observed trend of the 'migrantisation of care' in European welfare states; however, the actual modality of care-migration intersection varies reflecting historical and institutional contexts. This is why care-migration nexus research must go beyond the well-known welfare regime types. The Korean case can expand the geographical coverage and theoretical applicability of the intersection research by including a new welfare state regime type (productivist or developmental welfare states) and new patterns of migration (co-ethnic migration and marriage migration) which were rarely dealt with in this scholarship.

• Journal of Life Science
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• v.26 no.2
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• pp.253-258
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• 2016

In this study, nano-micelled curcumin was produced with natural sea salt with a view to comparing the in silico molecular binding affinity of pure curcumin compound to the active site of transthyretin. Using an optical light microscope and an electron microscope, it was found that the structure of the surface and the cross-section of nano-micelled curcumin was significantly different from natural sea salt. In particular, the crystal structure and nano-components in the nano-micelled curcumin were united, and the layer was more strongly stabilized than untreated salts. In the virtual 3D structure, in silico molecular docking study, the ligand binding affinity of nano-micelled curcumin to the transthyretin active site was found to be higher than that of pure curcumin. In addition, a nano-micelled curcumin formula interacted with more amino acid residues of transthyretin domains. The pharmacophore feature of the nano-micelled curcumin also showed more condensed and constrained features than normal curcumin. These results suggest that nano-micelled curcumin may effectively bind to and stabilize transthyretin, thereby regulating transthyretin-related physiological diseases. Collectively, the nano-micelled curcumin process suggests that normal curcumin can be modified more efficiently into the novel bio-functional chemical formula to stabilize the transthyretin structure. Therefore, the nano-micelled curcumin process can be applied to the field of the regulation of Alzheimer's disease.

• Korean Journal of Optics and Photonics
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• v.32 no.1
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• pp.1-8
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• 2021

We have studied a tiled-aperture coherent-beam-combining system based on constructive interference, as a way to overcome the power limitation of a single laser. A 1-watt-level, 3-channel coherent fiber laser and a 3-channel fiber array of triangular tiling with tip-tilt function were developed. A monitoring system, phase controller, and 3-channel phase modulator formed a closed-loop control system, and the SPGD algorithm was applied. Eventually, phase-locking with a rate of 5-67 kHz and peak-intensity efficiency comparable to the ideal case of 53.3% was successfully realized. We were able to develop the essential elements for a tiled-aperture coherent-beam-combining system that had the potential for highest output power without any beam-combining components, and a multichannel coherent-beam-combining system with higher output power and high speed is anticipated in the future.