• Communications for Statistical Applications and Methods
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• v.24 no.3
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• pp.211-226
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• 2017

The chain-ladder method, for which run-off data is employed is popularly used in the rate-adjustment and loss-reserving practices of non-life-insurance and health-insurance companies. The method is applicable when the underlying assumption of a consistent development pattern is in regards to a cumulative loss payment after the occurrence of an insurance event. In this study, a modified chain-ladder algorithm is proposed for when the assumption is considered to be only partially appropriate for the given run-off data. The concept of a structural-change point in the run-off data and its reflection in the estimation of unpaid loss amounts are discussed with numerical illustrations. Experience data from private health insurance coverage in Korea were analyzed based on the suggested method. The performance in estimation of loss reserve was also compared with traditional approaches. We present evidence in this paper that shows that a reflection of a structural-change point in the chain-ladder method can improve the risk management of the relevant insurance products. The suggested method is expected to be utilized easily in actuarial practice as the algorithm is straightforward.

• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.16-24
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• 1999

Design of SAW ladder filters has been performed by a rather trial and error method, that is, by modifying the design variables step by step until designed performance of the filter satisfies given specifications. In this work, optimal design method has been developed that automatically determines the detailed pattern of the SAW ladder filter to meet the specification once desired performance is given. As a first step for the development, the analysis tool for the SAW ladder filter has been produced by means of the Smith equivalent circuit analysis technique, and its validity has been verified through comparison of its calculation result with experimental data. With the analysis tool, we have investigated the performance variation of the filter with the change of its design factors, and the result has led to the optimal design algorithm. Validity and efficiency of the algorithm has been checked through test design of several SAW ladder filter samples on the market.

• Journal of Species Research
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• v.9 no.2
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• pp.147-161
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• 2020

Seven new species of two genera Scalarispongia and Smenospongia (Demospongiae: Dictyoceratida: Thorectidae) are described from Gageo Island and Jeju Island, Korea. Five new species of Scalarispongia are compared to nine reported species of the genus by the skeletal structure. Scalarispongia viridis n. sp. has regular ladder-like skeletal pattern arranged throughout the sponge body and has pseudo-tertiary fibres. Scalarispongia favus n. sp. is characterized by the honeycomb shape of the surface and is similar to Sc. flava in skeletal structure, but differs in sponge shape. Scalarispongia lenis n. sp. is similar to Sc. regularis in skeletal structure but has fibers that are smaller in size. Scalarispongia canus n. sp. has irregular skeletal structure in three dimensions and ladder-like which comes out of the surface and choanosome. Scalarispongia subjiensis n. sp. has pseudo-tertiary fibres and its regular ladder-like skeletal pattern occurs at the choanosome. Two new species of Smenospongia are distinguished from the other 19 reported species of the genus by the skeletal structure. Smenospongia aspera n. sp. is similar to Sm. coreana in sponge shape but new species has rarely secondary web and thin and thick bridged fibres at near surface. Smenospongia mureungensis n. sp. has very simple skeletal structure.

• Journal of Naturopathy
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• v.11 no.2
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• pp.79-84
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• 2022

Background: Exercise influences the generation of brain cells through learning and experience in the process of acquiring motor skills and helps improve brain function. It is necessary to scientifically verify how brain wave activity, a method of analyzing brain function, affects movement. Purposes: We scientifically identify the positive effects on EEG activity when applying complex functional linear ladder movements in an appropriate environment. Methods: After recruiting 30 male university students, we divided them into a linear ladder exercise group, a treadmill exercise group, and a control group, and exercise was applied and measured repeatedly for ten weeks. Results: There was a statistically significant change between groups in the left prefrontal lobe of alpha waves when exercise was applied (p < .05). Conclusions: Although exercise has a positive effect on EEG, line ladder exercise, which applies a complex pattern and produces more leg movement, appears to have a better impact on brain function than traditional aerobic exercise.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.9_10
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• pp.1475-1486
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• 2007

This study aims to develop knitted ware design to meet desire to express diversity in the modern fashion design so that we designed knitted ware by applying african geometric pattern and color to suggest new knitted ware design. We collect data about african texture pattern through technical books, publications, internet, and preceding research and visit and investigate the African museum. We investigate knitted Jacquard texture through preceding research and collect sample and data which is insufficient in the data source. The conclusions in this study are summarized as follows: First, African textile pattern is formulated with animism based on their religious view of art for a basis and African regards nature like animal and plant as a motive and interprets nature in the so that they can create symbolized geometric features that constitute African texture pattern. Those patterns is composed of extremely geometric figures so that they we fit to apply for color jacquad knit design. Second, color knitted jacquad can be distinguished by knitting method and status of knitting as 7 kinds of techniques such as Nomal, Bird'eye, Floating, Tubular, Ladder's back, Blister, Transfer Jacquard, and as a result of preceding research and knitting texture directly, jacquard technique makes different texture under same condition like consistent spinning rate and same crochet hook. Third, Bird'eye Jacquard used generally to make knitted ware and Ladder's back Jacquard, Tubular Jacquard used to make knitted ware light are fit to apply them to 7GG and 12GG machines. We design a cloak as a outer garment, a coat shaped like one-piece dress and a coat with hood by using Tubular Jacquard which can make thick texture and design a jacket, a skirt and a one-piece dress by using Bird'eye Jacquard. we make a light and flimsy one-piece dress by using Ladder's back Jacquard. Fourth, we apply the contrast of $4{\sim}6$ color and line and the contrast of texture and raw material to jacquard in order to emphasize texture property and visual property.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.63-68
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• 1996

Background: Interferon-$\gamma$ has various biologic effects, including antiviral effect, antitumor proliferative effect, activation of macrophage and B lymphocyte, and increased expression of major histocompatibility complex. Especially, antitumor proliferative effect of interferon-$\gamma$ has already been proved to be important in vivo as well as in vitro. And, clinical studies of interferon-$\gamma$ have been tried in lung cancer patients. However, the mechanism of antitumor effect of interferon-$\gamma$ has not yet been established despite of many hypotheses. "Necrosis" is a type of cell death which is well known to occur in the circumstances of severe stresses. In contrast, "apoptosis" is another type of cell death which occurs in such biological circumstances as embryonic development, regression of organs, and self-tolerance of lymphocytes. And, apoptosis is an active process of cell death in which cells are dying with fragmentations of their cytoplasms and nuclei. And, in the process of apoptosis the DNAs of cells are cleaved between nucleosomes by unidentified endonuclease and therefore DNAs of apoptotic cells result in a typical electrophoresis pattern known as DNA ladder pattern. Recently it has been suggested that cytotoxic effect of interferon-$\gamma$ occurs via apoptosis. To elucidate the mechanism of antitumor cytotoxic effect of interferon-$\gamma$, we microscopically observed a lung cancer cell line, A549 which was treated with interferon-$\gamma$. We observed A545 treated with interferon-$\gamma$ was dying fragmented. And so, we performed this study to find out that the mechanism of antitumor cytotoxic effect of interferon-$\gamma$ be apoptosis. Method: We treated A549, human lung cancer cell line with various concentration of interferon-$\gamma$ and quantified its cytotoxic effect of various periods, 24 hours, 72 hours and, 120 hours by MTT(dimethylthiazolyl diphenyltetrazolium bromide) bioassay. Also, after we treated A549 with 100 units/mi of interferon-$\gamma$ for 120 hours, we observed the pattern of cell death with inverted microscope and we extracted DNAs from the dead A549 cells and observed the pattern of 1.5% agarose gel electrophoresis with ethidium bromide staining. Result: 1) Cytotoxic effect of interferon-$\gamma$ on A549: For the first 24 hours, threre was little cytotoxic effect and for between 24 hours and 72 hours, there was the beginning of cytotoxic effect and for 120 hours there was increased cytotoxic effect. 2) Pattern of A549 cell death by interferon-$\gamma$: We observed with inverted microscope that A549 cells were dying fragmented. 3) DNA ladder pattern of gel electrophoresis: We observed DNA ladder pattern of gel electrophoresis of extracted DNAs from dead A549 cells. Conclusion: We concluded that the mechanism of interferon-$\gamma$induced cytotoxicity on lung cancer cell line, A549 be via apoptosis.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.83-87
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• 2000

To investigate exhausted-medium-induced apoptosis in human corneal epithelial(HCE) cells, this study was performed DNA gel electrophoresis, M30 CytoDEATH staining and FAS-FAS ligand ELISA. SV-40 transfected cells were grown to confluency in culture for 7days. The supernatant was harvested and filtered with $0.22{\mu}m$ filter paper. Fresh HCE cells were exposed to the filtered exhausted medium for 1~2 days. Apoptotic cells were prepared for DNA extraction and run the agarose gel for DNA ladder pattern. M30 CytoDEATH was used a tool for easy and reliable determination of very early apoptosis in HCE cells. The control and exhausted medium were assayed for soluble FAS/FAS ligand protein by ELISA. HCE cells exposed to exhausted medium showed a typical DNA ladder pattern. Sporadic M30 CytoDEATH positive cells were detected among HCE cells exposed to exhausted medium. Soluble FAS/FAS ligand levels were not elevated in the exhausted medium compared to the fresh medium control. This study suggests that possible mechanism of exhausted medium induced apoptosis does not include the FAS-FAS ligand system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.338-345
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• 2003

The purpose of this research was to investigate the anticancer effects of Dojeokseungki-tang(DJSKT) on the various leukemia cell lines. DJSKT treatment suppressed proliferation of cultured-HL60, Jurkat, L1210 cells and increased apoptosis of cultured-L1210, HL60, Molt4, Jurkat cells. DJSKT treatment induced apoptosis of Jurkat cells including the morphologic changes such as the 'ladder pattern' revealed by agarose gel electrophoresis of DNA in a dose-dependent manner. Administration of DJSKT induced apoptosis of transplanted-L1210 cells in vivo, and decreased of mitochondrial transmembrane potential of L 1210 and Jurkat cells in vitro. DJSKT treatment reduced the expression of bcl-2 proteins in Jurkat cells and increased ICE, c-myc, p53 mRNA expression in Molt4 cells. In conclusion, these results suggest that DJSKT might be usefully applied for anti-carcinogenic agent of leukemia.

• BMB Reports
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• v.31 no.2
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• pp.183-188
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• 1998

2-chloroethylethyl sulfide (CEES) is an alkylating agent that readily reacts with a wide variety of biological molecules causing metabolic abnormality. The mechanism of cell death during CEES injury is poorly understood. We have examined the effect of exposure of thymocytes with various concentrations of CEES to determine the pattern of cell death in thymocytes injury induced by CEES. In the present study, we show that two patterns of cell death occurred by either one of two mechanisms: apoptosis and necrosis. Exposure to low level of CEES (100 ${\mu}M$) for 5 h caused an induction of apoptosis on thymocytes, as identified by the following criteria: DNA fragmentation visualized by the characteristic "ladder" pattern was observed upon agarose gel electrophoresis and morphological features were revealed by microscopical observations. In contrast, exposure to high levels of CEES (500 ${\mu}M$) induce necrotic features such as cell lysis. Thus, depending on the concentrations, CEES can result in either apoptotic or necrotic cell damage. Our findings suggest that thymocytes which are not killed directly, but merely injured by low levels of CEES, are able to activate an internally-programmed cell death mechanism, whereas thymocytes receiving severe damages apparently can not.

• Korean Journal of Clinical Pharmacy
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• v.21 no.1
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• pp.30-35
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• 2011

The objective of this study was to find out drug use pattern of narcotic analgesics in university hospitals in Korea. A university hospital located in Kyungbuk province was chosen for this study. The drug use pattern was analyzed in terms of ingredient, administration route, patient type, and attending department. Amount of drug usage was counted by unit dose defined by the number of ampule or vial for injectable, tablet or capsule for oral, and each for patch preparations. Result showed that 11 narcotic analgesic ingredients were used during 2007-2009, and the drug usage was increased by about 20% annually during the period. Proportion of oral preparations used for pain management was about two third of all narcotic analgesics usage and kept increasing during the period. Proportion of the drug usage for outpatients was also steadily increased. Notably, the usage of oral preparations of oxycodone, morphine, and hydromorphone was rapidly increased for the management of cancer pain while the usage of codeine and codeine-containing composite preparations for cancer pain were minimal (<10%). About 90% of all narcotic analgesics were used by physicians in Internal Department, especially in Oncology Division of the Department. These findings suggest that pain management is becoming more aggressive and in agreement with WHO's guidelines regarding selection of administration route. However, in terms of 3-step ladder for cancer pain management, the drug use pattern was not congruent to WHO's guidelines. Therefore, in conclusion, it appears that physicians need to try to be congruent to the guidelines when using narcotic analgesics for cancer pain.