• Title/Summary/Keyword: 김동환

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Analysis of Tsunami Characteristics of Korea Southern Coast Using a Hypothetical Scenario (가상시나리오에 따른 남해안 지진해일 특성 연구)

  • Bumshick Shin;Dong-Seog Kim;Dong-Hwan Kim;Sang-Yeop Lee;Si-Bum Jo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.36 no.2
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    • pp.80-86
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    • 2024
  • Large-scale earthquakes are occurring globally, especially in the South Asian crust, which is experiencing a state of tension in the aftermath of the 2011 East Japan Earthquake. Uncertainty and fear regarding the possibility of further seismic activity in the near future have been on the rise in the region. The National Disaster Management Research Institute has previously studied and analyzed the overflow characteristics of a tsunami and the rate of flood forecasting through tsunami numerical simulations of the East Sea of South Korea. However, there is currently a significant lack of research on the Southern Coast tsunamis compared to the East Coast. On the Southern Coast, the tidal difference is between 1~4 m, and the impact of the tides is hard to ignore. Therefore, it is necessary to analyze the impact of the tide propagation characteristics on the tsunami. Occurrence regions that may cradle tsunamis that affect the southern coast region are the Ryukyu Island and Nankai Trough, which are active seafloor fault zones. The Southern Coast has not experienced direct damage from tsunamis before, but since the possibility is always present, further research is required to prepare precautionary measures in the face of a potential event. Therefore, this study numerically simulated a hypothetical tsunami scenario that could impact the southern coast of South Korea. In addition, the tidal wave propagation characteristics that emerge at the shore due to tide and tsunami interactions will be analyzed. This study will be used to prepare for tsunamis that might occur on the southern coast through tsunami hazard and risk analysis.

Development of Value-Added Products Using Seaweeds (해조류 가공식품 및 부산물을 이용한 제품 개발)

  • Park, Yang-Kyun;Kang, Seong-Gook;Jung, Soon-Teck;Kim, Dong-Han;Kim, Seon-Jae;Pak, Jae-In;Kim, Chang-Hyeug;Rhim, Jong-Whan;Kim, Jung-Mook
    • Journal of Marine Bioscience and Biotechnology
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    • v.2 no.3
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    • pp.133-141
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    • 2007
  • There are produced more than 600,000 tons of seaweeds every year along the coast of the Korea. Jeonnam province, south-west coast area, of Korea is producing 93% of total amounts of seaweeds. The laver, sea mustard, and tangleweed maintain stability in the output and has been exported as a simple product processing through drying or salting. It was evaluated the low value-added products and limited the expansion for the consumption of seaweeds. The seaweeds contains 40-60% carbohydrate and structurally different compared with land plant. The dietary fiber from seaweeds has been known the function of facilitating the bowl movement, excretion the heavy metal in the body, lowering the blood cholesterol level, anti-coagulant of blood, and anticancer. Especially, brown algae including sea mustard, seaweed fusiforme, and tangleweed contains alginic acid, laminarin, mannitol, fucoidan which are lowering the blood cholesterol level, lowering blood pressure, and fusion of blood clot. Agar-agar, carrageenan, and porphyran compound in red algae are known to antimutagenicity and anticoagulant function. In spite of potential of seaweed as a main bio-resource, there are lack of research to facilitate the consumption with its functional properties and consumers are unsatisfied with simple processing products. Also, the seaweed by-product dump into the sea and cause pollution of the seawater. Therefore, there are needed the scheme to promote the consumption of seaweeds. The development of value-added products, finding functional properties from seaweeds, development the functional feed for animal using seaweed by-products, and utilization of unused algae for food or other industrial uses will increase fisherman's income as well as serve as an aid for the people health due to its functional properties. Using by-product of seaweed and unexploited seaweed are needed to development of bio-degradable food packaging material and functional feed for animal.

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SVC Based Multi-channel Transmission of High Definition Multimedia and Its Improved Service Efficiency (SVC 적용에 의한 다매체 멀티미디어 지원 서비스 효율 향상 기법)

  • Kim, Dong-Hwan;Cho, Min-Kyu;Moon, Seong-Pil;Lee, Jae-Yeal;Jun, Jun-Gil;Chang, Tae-Gyu
    • Journal of IKEEE
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    • v.15 no.2
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    • pp.179-189
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    • 2011
  • This paper presents an SVC based multi-channel transmission technique. Transmission of high definition multimedia and its service efficiency can be significantly improved by the proposed method. In this method, the HD stream is divided into the two layer streams, i.e., a base layer stream and an enhancement layer stream. The divided streams are transmitted through a primary channel and an auxiliary channel, respectively. The proposed technique provides a noble mode switching technique which enables a seamless service of HD multimedia even under the conditions of abrupt and intermittent deterioration of the auxiliary channel. When the enhancement layer stream is disrupted by the channel monitoring in the mode switching algorithm, the algorithm works further to maintain the spatial and time resolution of the HD multimedia by upsampling and interpolating the base layer stream, consequently serving for the non disrupted play of the media. Moreover, the adoption of an adaptive switching algorithm significantly reduces the frequency of channel disruption avoiding the unnecessary switching for the short period variations of the channel. The feasibility of the proposed technique is verified through the simulation study with an example application to the simultaneous utilization of both Ku and Ka bands for HD multimedia broadcasting service. The rainfall modeling and the analysis of the satellite channel attenuation characteristics are performed to simulate the quality of service performance of the proposed HD broadcasting method. The simulation results obtained under a relatively poor channel (weather) situations show that the average lasting period of enhancement layer service is extended from 9.48[min] to 23.12[min] and the average switching frequency is reduced from 3.84[times/hour] to 1.68[times/hour]. It is verified in the satellite example that the proposed SVC based transmission technique best utilizes the Ka band channel for the service of HD broadcasting, although it is characterized by its inherent weather related poor reliability causing severe limitations in its independent application.

Bilateral retinoblastoma: Long-term follow-up results from a single institution (단일기관의 장기추적 결과)

  • Choi, Sang Yul;Kim, Dong Hwan;Lee, Kang Min;Lee, Hyun Jae;Kim, Mi-Sook;Lee, Tai-Won;Choi, Sang Wook;Kim, Dong Ho;Park, Kyung Duk;Lee, Jun Ah
    • Clinical and Experimental Pediatrics
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    • v.52 no.6
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    • pp.674-679
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    • 2009
  • Purpose : The authors aimed to analyze the long-term effects of treatments, especially external beam radiotherapy (EBRT), in bilateral retinoblastoma patients. Methods : This retrospective study analyzed the medical records of 22 bilateral retinoblastoma patients who were registered between October, 1987 and October, 1998 and followed-up for more than 10 years. They were treated by enucleation, EBRT, and systemic chemotherapy. Age at diagnosis, sex, delay prior to treatment, Reese-Ellsworth (RE) classification, and the local treatment modalities were analyzed in relation to recurrence-free survival (RFS) and complications. Results : Median age at diagnosis was 7.0 months (range 1.7-31.6 months). Leukocoria was the most common presenting feature. Two patients had a familial history. The RE classifications of the 44 eyes were group II in 4, III in 14, IV in 4, and V in 22. At the end of a median follow-up period of 141 months (range 55-218 months), 20 patients were alive. The 10-year ocular survival rate of the 44 eyes was $56.8{\pm}7.5%$. The 10-year RFS and ocular survival rate of the 29 eyes treated by combined EBRT and chemotherapy were 75.9% and 86.2%, respectively. Treatment delay (>3 months) was found to be related to higher risk of recurrence. Complications after EBRT were cataract, retinal detachment, phthisis bulbi, and facial asymmetry. No patient developed a second malignancy during the follow-up period. Conclusion : Early detection and prompt treatment can increase ocular survival rates. In addition, careful attention should be paid to possible long-term sequelae in these patients.

Pulmonary tuberculosis misdiagnosed as lung Metastasis in childhood cancer patients (소아암 환자에서 암의 전이로 오인된 폐결핵)

  • Lee, Hyun-Jae;Kim, Dong-Whan;Lee, Kang-Min;Park, Kyung-Duk;Lee, Jun-Ah;Cho, Soo-Yeon;Kook, Yoon-Hoh;Kim, Hee-Youn;Kim, Dong-Ho
    • Clinical and Experimental Pediatrics
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    • v.52 no.8
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    • pp.904-909
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    • 2009
  • Purpose : The differential diagnosis for a pulmonary nodule is intriguing in cancer patients. Metastasis might be a preferential diagnosis, and yet possibilities of other medical conditions still exist. Pulmonary tuberculosis should be enlisted in the differential diagnosis for a pulmonary nodule in cancer patients in Korea. This study was aimed at analyzing the incidence and clinical features of pulmonary tuberculosis that were misdiagnosed as pulmonary metastasis during radiologic follow-up in pediatric cancer patients. Methods : We retrospectively studied 422 cancer patients less than 18 years old in the Korea Cancer Center Hospital from January 2001 to June 2007. We collected episodes of lung metastasis of primary tumor and tuberculosis during treatment or follow-up, and analyzed medical records. Results : There were 5 cases of tuberculosis confirmed after surgery which were initially regarded as cancer. Two patients had respiratory symptoms such as cough and sputum but the other 3 patients did not. One patient had a family history of tuberculosis. Acid-fast M. tuberculosis was found in one case upon tissue specimen analysis. Two cases were Mantoux positive and the sputum examination was negative in all cases. The polymerase chain reaction for tuberculosis on a pathologic specimen was used to differentiate M. tuberculosis from non-tuberculosis mycobacterium (NTM). It was positive in one case. Lung lesions in one case showed a concurrence of tuberculosis along with lung metastasis. One of these patients died after cancer recurrence. Conclusion : It is necessary to consider the possibility of tuberculosis when a lung mass is newly detected during treatment or follow-up in patients with childhood cancer.

Pathogenicity bioassay of entomopathogenic nematode, Steinernema carpocapsae GSN1 strain (Nematoda: Steinernematidae) on the shiitake fungus moth, Morophagoides moriutii (Lepidoptera: Tineidae) (표고버섯좀나방에 대한 곤충병원성 선충의 병원성 검정)

  • Kim, Hyeong Hwan;Kim, Dong Hwan;Cho, Myung Rae;Yang, Chang Yeol;Kang, Taek Jun;Jeon, Sung Wook;Song, Jin Sun;Jung, Young Hak;Park, Hae Woong;Park, Chung Gyoo;Choo, Ho Yul
    • Journal of Mushroom
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    • v.12 no.4
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    • pp.357-362
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    • 2014
  • Pathogenicity of Steinernema carpocapsae GSN1 strain was evaluated against Morophagoides moriutii larvae. In Petridish tests, insect mortality by the nematode was dose dependent, which increased with dose from 5 to 160 infective juveniles(IJs)/larva. Pathogenicity against fourth-instar larvae was higher than the rate of corresponding second- and third-instar larvae, showing 100% insect mortality with the dose of 40 IJs/$4^{th}$ instar larva and 80 IJs/$2^{nd}$ or $3^{rd}$ instar larvae. Lethal concentration values at 50% ($LC_{50}$) of S. carpocapsae GSN1 strain were 4.2 IJs/$2^{nd}$ instar larva; 8.5 IJs/$3^{rd}$ instar larva; and 2.3 IJs/$4^{th}$ instar larva, respectively. The number of nematodes established in M. moriutii larvae after infection increased in the increment of dose and insect developmental stage. The highest number of nematodes was harvested from fourth instar larvae of M. moriutii at a dose of 160 IJs per larva, showing 22.5 nematodes per insect larva. Nematode reproductive capacity was related to insect developmental stage, showing 6,335 IJs/$2^{nd}$ instar larva, 21,660 IJs/$3^{rd}$ instar larvae, and 88,700 IJs/$4^{th}$ instar larvae.

Effects of the In Vitro Produced Hanwoo Blastocyst Stage, In Vitro Culture Day and Blastocyst Grade on the Production of Claves (한우 체외 수정란의 배반포 단계, 체외 배양 일령 및 등급이 산자의 생산에 미치는 영향)

  • Park, Y.S.;Kim, S.S.;Kim, D.H.;Park, H.D.
    • Journal of Embryo Transfer
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    • v.21 no.4
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    • pp.299-306
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    • 2006
  • This study examined the effects of the in vitro produced (IVP) Hanwoo blastocyst stage (blastocyst, expanded blastocyst and hatched blastocyst), in vitro culture day (7, 8, and 9) and blastocyst grade (1, 2 and 3) on the pregnancy rate, gestation length, birth weight, the incidence of dystocia and twining rate after embryo transfer (ET). The pregnancy and abortion rates were significantly higher in the blastocyst (B) stage (64.4%) and in the hatched blastocyst (HB) stage (21.4%), respectively, than in those of the other developmental stages (p<0.05). The pregnancy rate of Day 7 embryos (49.0%) was significantly higher than those of Days 8 and 9 embryos (36.4 and 15.4%), but the abortion rates were similar (0 to 10.7%). There were no significant differences in the pregnancy (41.4 to 42.5%) and abortion (9.3 to 16.5%) rates among the three grades of embryos. There were no significant differences in gestation length, birth weight and the incidence of dystocia among the three development stages, but the twinning rate was significantly higher in the HB stage (p<0.05). The pregnancy rate, the incidence rate of dystocia and twinning rate were similar among the three different culture days, however birth weight was significantly heavier in calves from Day 9 embryos than in those from Days 7 and 8 embryos. The mean gestation length of grades 1 and 2 embryos (278.5 and 276.1 days) were significantly longer than that of grade 3 (p<0.05), but birth weight, the incidence of dystocia and twinning rate did not significantly differ. The mean gestation length in single calves was significantly longer than that in twin calves (278.5 vs. 272.5 days, p<0.05). In addition, the mean birth weight in single calves was significantly greater than that in twin calves (29.6 vs. 22.3 kg, p<0.05). Finally, the sex ratios and mean mortality rates between single and twin calves were similar.

Screening of yeast for alcoholic fermentation of no sugar-added tomato concentrate (토마토 농축액을 이용한 무가당 알코올 발효를 위한 효모의 선발)

  • Kim, Dong-Hwan;Moon, Jae-Nam;Lee, Seul;Lee, Soo-Won;Moon, Hey-Kyung;Kim, Gwi-Young
    • Food Science and Preservation
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    • v.23 no.4
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    • pp.591-598
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    • 2016
  • The purpose of this study was to screen desirable yeast strains for alcoholic fermentation of tomato paste without sugar addition. The moisture, crude protein, crude fat, ash, and soluble nitrogen contents of the tomato paste ($25^{\circ}Brix$) were found to be 67.33%, 1.90%, 0.03%, 0.02%, and 30.72%, respectively. Free sugars found in the paste were fructose and glucose. Most abundant free amino acids of the paste were glutamic, aspartic, and ${\gamma}$-aminobutyric acids. Total seven yeast strains (Saccharomyces cerevisiae KDH (TWA), S. cerevisiae Lalvin ICVD-47 (TWB), S. cerevisiae Lalvin RC-212 (TWC), S. cerevisiae Lalvin K1-V1116 (TWD), S. bayanus Lalvin EC-1118 (TWE), S. cerevisiae Enoferm (TWF), and S. cerevisiae DJ97(KCTC8842P) (TWG)) were tasted for alcohol fermentation of the tomato paste. The highest alcohol content (8.2%) and the lowest residual sugar content ($13.25^{\circ}Brix$) were observed in the tomato paste fermented using the S. cerevisiae Lalvin ICVD-47 strain (TWB) after 3 day and 4 day of fermentation, respectively. Sugar and reducing sugar contents, and pH of the tomato paste were not remarkably affected by the difference in yeast strains used, showing $13.25{\sim}13.45^{\circ}Brix$, 28.37~28.48 mg/mL, and 4.43~4.54, respectively, after 4 day of fermentation. Color and total acid content were significantly affected by the types of yeast strains and fermentation time, but the numerical changes were negligible. These results indicate that TWB would be the suitable strain for alcoholic fermentatiom of tomato paste based on its highest alcohol production and the lowest residual sugar content produced during fermentation.

Prognostic Value of Normal Exercise $^{99m}Tc$-MIBI Myocardial Perfusion SPECT: Comparison with Exercise Electrocardiography and Coronary Angiography ($^{99m}Tc$-MIBI 운동부하 심근관류 SPECT에서 정상소견을 보인 환자의 예후: 운동부하 심전도와 관동맥 조영소견과의 비교)

  • Lee, Sang-Woo;Lee, Jae-Tae;Chun, Kyung-Ah;Kang, Do-Young;Kim, Dong-Hwan;Cho, Yong-Keun;Chae, Shung-Chull;Lee, Kyu-Bo
    • The Korean Journal of Nuclear Medicine
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    • v.34 no.3
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    • pp.199-206
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    • 2000
  • Purpose: Myocardial perfusion scintigraphy is a useful technique to diagnose and to predict prognosis in patients with suspected or known coronary artery disease. The purpose of the present study is to evaluate the prognostic value of normal exercise $^{99m}Tc$-MIBI myocardial perfusion single photon emission computed tomography (SPECT) and to analyze results with regard to those of exercise electrocardiography or coronary angiography. Materials and Methods: We evaluated 301 patients (mean age $52{\pm}10$ years, 166 males and 135 females) with normal exercise $^{99m}Tc$-MIBI myocardial perfusion SPECT performed for suspected coronary artery disease. Subject were evaluated for cardiac events and followed for 8-55 months (mean $19{\pm}10$ months) after imaging. Results: During the follow-up period, there was no cardiac death but only one non-fatal myocardial infarction (event rate 0.21% per year). In addition, only one patient underwent coronary revascularization. There was no significant difference in cardiac event rate between patients with positive (n=27) and negative (n=235) exercise electrocardiography (p:NS). There was no cardiac event in 17 patients who underwent coronary angiography (4 patients with >50% luminal narrowing, 2 patients with vasospasm and 11 patients with no significant lesion). Conclusion: Patients with normal exercise $^{99m}Tc$-MIBI myocardial perfusion SPECT has a very low risk for cardiac events regardless of exercise electrocardiographic and coronary angiographic findings.

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Characteristics of Methicillin-resistant Staphylococcus aureus Nasal Colonization Among Neonatal Unit Staff and Infection Control Measures (일개 병원 신생아실 근무 의료인에서 시행한 비강 내 MRSA 집락의 특성 및 전파예방에 관한 보고)

  • Kim, Dong Hwan;Kim, Sun Mi;Park, Ji Young;Cho, Eun Young;Choi, Chang Hee
    • Pediatric Infection and Vaccine
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    • v.16 no.2
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    • pp.131-141
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    • 2009
  • Purpose : In February 2007, an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections occurred in two newborns in the neonatal unit of Sahmyook Seoul Hospital. We performed this study to investigate the characteristics of MRSA nasal carriage among neonatal unit staffs and the effective infection control measures. Methods : Nasal swab specimens were obtained from the neonatal unit staff for the presence of MRSA. MRSA-colonized staffs were offered decolonization therapy with oral trimethoprim-sulfamethoxazole or 2% mupirocin ointment. Every 2-4months after decolonizaton, repeat nasal swab specimens were obtained. Also, samples from the neonatal unit environment and room air were collected. Results : Successful decolonization was achieved in 92% of the cases in 2 weeks after decolonization therapy, but most of the staffs were recolonized after several months. The nature of antibiotic susceptibility was changed from multi-drugsusceptible to multi-drug-resistant. The most frequently contaminated objects were dressing carts, computer keyboards, bassinets and washbowls. In environmental cultures using the settle microbe count method, the colony counts were decreased significantly at the last study period compared with the first study period in the neonatal room, breastfeeding room, service room, and dressing room (P <0.05). Conclusion : Effective control of sustained MRSA transmission within an institution may require prompt identification, treatment, and monitoring of colonized and/or infected staffs. However, nasal decolonization therapy may induce multi-drugresistant MRSA infection and had no effect on decreasing the MRSA nasal carriage rate in our study. Other factors might be more important, such as improving staff education, increasing hand hygiene practices, and environmental sterilization for controlling MRSA infections.

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