• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.166-166
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• 2023

Compound hazards (CHs) are two or more extreme climate events combined which occur simultaneously in the same region at the same time. Compared to individual hazards, the combination of hazards that cause CHs can result in greater economic losses and deaths. While several extreme climate events have been recorded across Asia for the past decades, many studies have only focused on a single hazard. In this study, we assess the spatiotemporal pattern of dry compound hazards which includes drought, heatwave, fire and wind across Asia for the last 42 years (1980-2021) using the historical data from ERA5 Reanalysis dataset. We utilize a daily spatial data of each climate event to assess the occurrence of such compound hazards on a daily basis. Heatwave, fire and wind hazard occurrences are analyzed using daily percentile-based thresholds while a pre-defined threshold for SPI is applied for drought occurrence. Then, the occurrence of each type of compound hazard is taken from overlapping the map of daily occurrences of a single hazard. Lastly, a multivariate assessment are conducted to quantify the occurrence frequency, hotspots and trends of each type of compound hazard across Asia. By conducting a multivariate analysis of the occurrence of these compound hazards, we identify the relationships and interactions in dry compound hazards including droughts, heatwaves, fires, and winds, ultimately leading to better-informed decisions and strategies in the natural risk management.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.1
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• pp.9-17
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• 2014

Electrical compound action potential (ECAP) can be recorded on cochlear implant. This study will investigate stimulation and recording to enhance the efficacy of ECAP. 34 articles was used. We analyzed pulse and stimulating condition, artifact suppression, recording condition. The cathod-leading biphasic pulse was used with as short as possible pulse width and inter phase gap for the efficacy of neural firing, stable threshold and preventing neural degeneration. Around C-level was stimulated to apical, middle and basal turn of cochlea. Artifact was eliminated by forward-masking, template-subtraction technique. For clearer waveform, we need to change distance between stimulating and recording electrode, the gain of amplification, number of average.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.83-90
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• 2004

This paper proposes a tool path generation method for machining impellers with 5-axis machining center. The shape of impeller is complex, being composed of pressure surface, suction surface and leading edge, and so on. The compound surface which is made of ruled surface such as pressure surface and suction surface and leading edge such as fillet surface, makes the tool path generation much complicated. To achieve efficient roughing, cutting area is divided into two region and then tool radius of maximum size that do not cause tool intereference is selected for shortening machining time. In finishing, accuracy is improved using side cutting for blade surface and point milling for leading edge.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.3114-3114
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• 2001

During the last years phytochemistry and phytopharmaceutical applications have developed rapidly and so there exists a high demand for faster and more efficient analysis techniques. Therefore we have established a near infrared transflectance spectroscopy (NIRS) method that allows a qualitative and quantitative determination of new polyphenolic pharmacological active leading compounds within a few seconds. As the NIR spectrometer has to be calibrated the compound of interest has at first to be characterized by using one or other a combination of chromatographic or electrophoretic separation techniques such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC), capillary electrophoresis (CE), gas chromatography (GC) and capillary electrochromatography (CEC). Both structural elucidation and quantitative analysis of the phenolic compound is possible by direct coupling of the mentioned separation methods with a mass spectrometer (GC-MS, LC-MS/MS, CE-MS, CEC-MS) and a NMR spectrometer (LC-NMR). Furthermore the compound has to be isolated (NPLC, MPLC, prep. TLC, prep. HPLC) and its structure elucidated by spectroscopic techniques (UV, IR, HR-MS, NMR) and chemical synthesis. After that HPLC can be used to provide the reference data for the calibration step of the near infrared spectrometer. The NIRS calibration step is time consuming, which is compensated by short analysis times. After validation of the established NIRS method it is possible to determine the polyphenolic compound within seconds which allows to raise the efficiency in quality control and to reduce costs especially in the phytopharmaceutical industry.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.18-23
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• 1998

In order to obtain leading compound for the development of new pesticide through the organic synthesis of natural products, the synthesis of ricinine, an active compound of Ricinus communis, was established and biological activities of synthetic compounds against insects were examined. The synthetic scheme of ricinine was composed of four steps by the spontaneous condensation of the cyanoacetyl chloride. A modified synthetic process was also estabilshed to enhance the synthetic yield by simple cyclization of ethoxymethylene malononitrile. In the bioassay results of synthetic ricinine and intermediates on four insects, the mortality of ricinine on brown planthopper (BPH, Nilaparvata lugens) and pea weevil(PW, Bruchus rufimanus) was 80% and 75% at the concentration of 1,000 ${\mu}g/ml$ respectively. Chloronorricinine and chlororicinic acid having chloride group in molecular structure gave 60% mortality on two-spotted mite (TSSM, Tetranychus urticae) at the concentration of 500 ${\mu}g/ml$. The mortality of compounds on house mosquito (HM, Culex pipens pallens) was meager at 10 ${\mu}g/ml$ level.

• Journal of the Korean Society for Heat Treatment
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• v.37 no.2
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• pp.49-57
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• 2024

We investigated the changes in microstructure and surface roughness of the compound layer of GC250D gray cast iron, commonly used in brake discs, during gas nitriding. The gas atmosphere of the nitriding process was controlled with a hydrogen partial pressure of 49.5%, and the process was conducted at a nitriding temperature of 520℃ with various process times. As the nitriding process time of the GC250D material increased, both the depth of hardening and the thickness of the compound layer increased, with a maximum surface hardness of approximately 1265 HV_0.1 was measured. Additionally, the surface roughness increased with the process time. Phase analysis of the compound layer revealed an increase in the proportion of the γ' phase as the nitriding process time increased. Changes in the formation of the compound layer were observed depending on the orientation of graphite within the material, leading to the formation of wedges. Therefore, the increase in surface roughness appears to be attributed to the uneven compounds, the expansion of the compound layer and wedges formed on the surface during the nitriding process.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.3
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• pp.59-63
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• 2010

Immersion Sn plating was produced on Cu foil by distributing nano-sized diamonds (ND). The ND distributed on the coating surface broke the continuity of Sn-oxide layer, therefore leading to penetrate the molten solder through the oxide and retarding the wettability degradation during a reflow process. Furthermore, the ND in the Sn coating played a role of diffusion barrier for Sn atoms and decreased the growth rate of intermetallic compound ($Cu_6Sn_5$) layer during the solid-state aging. The study confirmed the importance of ND to improve the wettability and reliability of the Sn plating. Complete dispersion of the ND within the immersion Sn plating needs to be further developed for the electronic packaging applications.

• Journal of Arbitration Studies
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• v.31 no.1
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• pp.55-81
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• 2021

Awarding interest in international arbitration remains one of the most challenging areas for tribunals and parties given the myriad of issues that arise. This article seeks to provide an overview of how international arbitral tribunals grant delay interest. It reviews the various issues that international arbitral tribunals face concerning pre-award and post-award interest, determining the appropriate interest rate, surrounding simple or compound interest, and the complex issue of choice of law. A comparative context is provided by surveying the laws of major jurisdictions from both the common law and civil law and the regulations of leading arbitral institutions. It concludes with a review of the law, jurisprudence, and practice in Korea related to delay interest and how Korean tribunals under the KCAB Domestic and International Rules have determined delay interest in recent years.

• Journal of Ginseng Research
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• v.42 no.2
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• pp.165-174
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• 2018

Background: Extended endoplasmic reticulum (ER) stress may initiate apoptotic pathways in cancer cells, and ER stress has been reported to possibly increase tumor death in cancer therapy. We previously reported that caspase-8 played an important role in compound K-induced apoptosis via activation of caspase-3 directly or indirectly through Bid cleavage, cytochrome c release, and caspase-9 activation in HL-60 human leukemia cells. The mechanisms leading to apoptosis in A549 and SK-MES-1 human lung cancer cells and the role of ER stress have not yet been understood. Methods: The apoptotic effects of compound K were analyzed using flow cytometry, and the changes in protein levels were determined using Western blot analysis. The intracellular calcium levels were monitored by staining with Fura-2/AM and Fluo-3/AM. Results: Compound K-induced ER stress was confirmed through increased phosphorylation of $eIF2{\alpha}$ and protein levels of GRP78/BiP, XBP-1S, and $IRE1{\alpha}$ in human lung cancer cells. Moreover, compound-K led to the accumulation of intracellular calcium and an increase in m-calpain activities that were both significantly inhibited by pretreatment either with BAPTA-AM (an intracellular $Ca^{2+}$ chelator) or dantrolene (an RyR channel antagonist). These results were correlated with the outcome that compound K induced ER stress-related apoptosis through caspase-12, as z-ATAD-fmk (a specific inhibitor of caspase-12) partially ameliorated this effect. Interestingly, 4-PBA (ER stress inhibitor) dramatically improved the compound K-induced apoptosis. Conclusion: Cell survival and intracellular $Ca^{2+}$ homeostasis during ER stress in human lung cancer cells are important factors in the induction of the compound K-induced apoptotic pathway.

• Membrane Journal
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• v.13 no.2
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• pp.110-117
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• 2003

Sulfonated polyimides had been utilized and studied widely as available materials in chloro-alkali electrolysis, cationic exchange resins, and so on. However, a slow decrease in performance during experiments had been reported, which could be attributed to a loss of ionic conductivity related to either a continuous dehydration or polymer degradation. One of main reasons to account for the degradation of sulfonated polymers is the hydrolysis leading to polymer chain scission and decrement of molecular weight. Therefore, the objective of our study was to investigate possible imide cycle and additional ester bond cleavage connected with $SO_3$H presence under hydrated condition. In order to confirm and obtain as clear information as possible about breakages of bonds via $^1H\; and \;^{13}C$ NMR and IR spectroscopic analyses, our study was performed by model compound. Consequently, model compounds with both phthalic and naphthalenic imide ring and ester bonds were synthesized to evaluate the hydrolysis stability of sulfonated polyimide. The experiments were performed for prepared model compounds before and after aging in deionized water at $80^{\circ}C$ and were terminated by lyophilization technique. The aging products were finally analyzed by NMR and IR spectroscopy.