• Title/Summary/Keyword: cold region

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Evaluation on Thermal Performance of Thermosyphon by Numerical Analysis (열사이펀의 열성능 산정을 위한 수치해석 연구)

  • Jang, Changkyu;Choi, Changho;Lee, Jangguen;Lee, Chulho
    • Journal of the Korean Geotechnical Society
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    • v.30 no.9
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    • pp.57-66
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    • 2014
  • The ground in cold region consists of active and permafrost layers. The active layer at the unstable state may cause ground corrosion and uplift, when the temperature of frozen ground increases due to seasonal changes. The thermosyphon is one of the stabilization methods to maintain the ground stability in the frozen ground. The thermosyphon is a closed two-phase convection device that extracts heat from the ground and discharges it into the atmosphere. In this study, ground freezing experiment using a thermosyphon and simulated ground with the isolation material was conducted to evaluate the thermal performance of the thermosyphon. In order to consider the thermal performance of the thermosyphon, commercial numerical program (TEMP/W) was adopted. Likewise, the thermal performance of thermosyphon and thermal properties of ground were applied in the numerical model. In a series of comparisons with experiment results and numerical study, thermal performance of thermosyphon can be evaluated.

Testing the Convergence of Military Expenditure and Arms Imports in Northeast Asian Countries (동북아 국가의 국방비 지출 및 군수물자 수입 수렴성 검정)

  • Rhee, Hyun-Jae
    • The Journal of the Korea Contents Association
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    • v.13 no.2
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    • pp.475-487
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    • 2013
  • The aim of this study is to examine an existence of mutual interdependency in terms of military expenditure and arms imports between Northeast Asian countries such as South Korea, North Korea, China, Japan, and U.S. Recently, the mood of post cold war and intensified globalization lead to be disarmament in pursuing a policy on national defence in many countries. Since potential menace to national security has been receiving more concern rather than a direct armed clash, mutual interdependency on military spending should be fully understood. For a methodological tools, ${\beta}$ and ${\sigma}$-convergences, convergence with rational expectation, and Granger causality test are employed. Empirical evidence shows that the convergences which are evaluated by ${\beta}$, ${\sigma}$, and by a model based on rational expectation are in general revealed, and differences are more sensitive to a military decision making procedures. Granger causality, however, is not being existed. To this end, it would be concluded that the Northeast Asian countries are going with a trend in the world than forming their own tendency in this region.

Visualizing Spatial Information of Climate Change Impacts on Social Infrastructure using Text-Mining Method (텍스트마이닝 기법을 활용한 사회기반시설 기후변화 영향의 공간정보 표출)

  • Shin, Hana;Ryu, Jaena
    • Korean Journal of Remote Sensing
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    • v.33 no.5_3
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    • pp.773-786
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    • 2017
  • This study was to analyze data of climate change impacts on social infrastructure using text-mining methodology, and to visualize the spatial information by integrating those with regional data layers. First of all, the study identified that the following social infrastructure; power, oil and resource management, transport and urban, environment, and water supply infrastructures, were affected by five kinds of climate factors (heat wave, cold wave, heavy rain, heavy snow, strong wind). Climate change impacts on social infrastructure were then analyzed and visualized by regions. The analysis resulted that transport and urban infrastructures among all kinds of infrastructure were highly impacted by climate change, and the most severe factors of the climate impacts on social infrastructure were heavy rain and heavy snow. In addition, it found out that social infrastructure located in Seoul and Gangwon-do region were relatively largely affected by climate change. This study has significance that atypical data in media was used to analyze climate change impacts on social infrastructure and the results were translated into spatial information data to analyze and visualize the climate change impacts by regions.

Proposed Treatment Protocol for Frostbite: A Retrospective Analysis of 17 Cases Based on a 3-Year Single-Institution Experience

  • Woo, Eun-Kyung;Lee, Jong Wook;Hur, Gi-Yeun;Koh, Jang-Hyu;Seo, Dong-Kook;Choi, Jai-Ku;Jang, Young-Chul
    • Archives of Plastic Surgery
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    • v.40 no.5
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    • pp.510-516
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    • 2013
  • Background This paper discusses the treatment protocol for patients with frostbite. Methods We performed a retrospective analysis of a series of 17 patients with second- and higher-degree frostbite who had been treated at our medical institution between 2010 and 2012. Results Our clinical series of patients (n=17) included 13 men and four women, whose mean age was $42.4{\pm}11.6$ years (range, 22-67 years). The sites of injury include the foot in six patients (35.3%), the hand in six patients (35.3%) and the facial region in five patients (29.4%). Seven patients with second-degree frostbite were completely cured with only conservative treatment during a mean period of $12.7{\pm}3.3$ days (range, 8-16 days). Of the five patients with third-degree frostbite, two underwent skin grafting following debridement, and the remaining three achieved a complete cure with conservative treatment during a mean period of $35{\pm}4.3$ days (range, 29-39 days). Five patients with fourth-degree frostbite were treated with surgical procedures including amputation. Conclusions With the appropriate conservative management in the early stage of onset, surgeons should decide on surgery after waiting for a sufficient period of time until the demarcation of the wound. Continuous management of patients is also needed to achieve functional recovery after a complete cure has been achieved. This should also be accompanied by patient education for the avoidance of re-exposure to cold environments.

Studies on Changes and Future Projections of Subtropical Climate Zones and Extreme Temperature Events over South Korea Using High Resolution Climate Change Scenario Based on PRIDE Model (남한 상세 기후변화 시나리오를 이용한 아열대 기후대 및 극한기온사상의 변화에 대한 연구)

  • Park, Chang Yong;Choi, Young Eun;Kwon, Young A;Kwon, Jae Il;Lee, Han Su
    • Journal of the Korean association of regional geographers
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    • v.19 no.4
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    • pp.600-614
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    • 2013
  • This study aims to examine spatially-detailed changes and projection of subtropical climate zones based on the modified K$\ddot{o}$ppen-Trewartha's climate classification and extreme temperature indices using $1km{\times}1km$ high resolution RCP 4.5 and RCP 8.5 climate change scenarios based on PRIDE model over the Republic of Korea. Subtropical climate zones currently located along the southern coastal region. Future subtropical climate zones would be pushed northwards expanding to the western and the eastern coastal regions as well as some metropolitan areas. For both scenarios, the frequency of cold-related extreme temperatures projects to be reduced while the frequency of hot-related ones projects to be increased. Especially, hot days with $33^{\circ}C$ or higher temperature projects to occur more than 30 days over the most of regions except for some mountain areas with high altitudes during the period of 2070~2100. This study might provide essential information to make climate change adaptation processes be enhanced.

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Temporal and Spatial Variations of Size-structured Phytoplankton in the Asan Bay (아산만 식물플랑크톤 크기구조의 시.공간적 변동)

  • Hyun Bong-Kil;Sin Yong-Sik;Park Chul;Yang Sung-Ryull;Lee Young-Joon
    • Korean Journal of Environmental Biology
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    • v.24 no.1 s.61
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    • pp.7-18
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    • 2006
  • Samples were collected from five stations monthly from October 2003 to September 2004 to investigate seasonal variation of size structure of phytoplankton and relationship between size-fractionated phytoplankton and environmental factors in the Asan Bay. The contribution of large cells (microphytoplankton, $>20\;{\mu}m$) to total concentrations of chlorophyll $\alpha$ was higher than small cells (nanophytoplankton, $3\sim20\;{\mu}m$; picophytoplankton, $<3\;{\mu}m$) during the sampling period. Especially, large cells contributed 80% to the total chlorophyll a from February, 2004 to April 2004 when chlorophyll $\alpha$ concentrations were high. The size structure of phytoplankton shifted from micro-size class to nano-size class and picophytoplankton rapidly increased when phytoplankton biomass decreased in May 2004. Microphytoplankton exhibited a high biomass in the upper region during winter-spring season whereas nano- and picophytoplankton showed two peaks in the middle-lower regions (Station 3,5) during spring and summer. Microphytoplankton are most likely controlled by water temperature and nutrient supply during the cold season whereas nano- and picophytoplankton may be affected by stratification, light exposure during the warm season.

Influences of Thermal Effluents on the Epilithic Algal Community in Small Stream Originating from the Seokjung Hot Spring (온천 배수 유입에 따른 소형 하천의 생태계 변화와 회복에 관한 연구 -소형 하천에서 온천 배수가 부착조류 군집에 미치는 영향)

  • 정연태;문연자;김미연;최민규;길봉섭
    • Korean Journal of Environmental Biology
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    • v.17 no.3
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    • pp.345-358
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    • 1999
  • To study the influences of thermal effluents flowing from hot spring on epilithic algal community, seasonal survey was carried out at stream and its watersheds from Seokjeong hot spring in Chollabuk-Do, Korea. Totally 7 points were divided into three regions fur sampling of water and epilithic algae, such as the direct effected, uneffected and the mixed region, respectively. At the discharging points of effluents, a dark-green cyanobacterial mat were remarkably constructed, mainly by two cyanobacteria, Oscillatoria and Phormidium. The mat formation were more obvious at low temperature than any other season, and even result in disappear with downstream and season. Totally, one hundred and fifty-three taxa of epilithic algae were classified with 15 unidentified species. Among the, diatoms occupied 58% of total species, whereas cyanobacteria was 67% of total biomass, comparatively. In terms of stream direction, relative abundance of cyanobacteria was only limited in the upstream in cold season, and result in this pattern disappeared with season change. Although all physicochemical variables at the discharging points, was very high, compare to other points, they were quickly decreased downstream. Among them, some heavy metals were not detected or below the detection levels at downstream. Nitrate nitrogen increased with downstream, as well as phosphorus and sulfate have a similar trend throughout, while ammonia quickly decreased in the initial period of discharging effluents. This suggest that although the thermal effluent with high temperature and organic compounds could polluted the small study stream, various contributions such as flowing water, intake of uneffected streawater and collaboration of cyanobacterial mat and stream bottom gradually induces a stable water system.

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The Literature Study on Classification of Cause and the Effect of Acupuncture and Moxibustion Treatment for Dentalgia (치통(齒痛)의 병인병기(病因病機) 및 침구치료(鍼灸治療)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Lee, Seong-no;Lee, Hyun;Lee, Byung-ryul
    • Journal of Haehwa Medicine
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    • v.10 no.1
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    • pp.269-286
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    • 2001
  • Objectives : This Investigation was aimed to find out the Classification of Cause and the Effect of Acupuncture and Moxibustion Treatment for Dentalgia Methods : We surveyed the oriental medical books from $\ll$HungTiNeiChing$\gg$ to recent published books concerning the Acupuncture therapy for Dentalgia Results : 1. Since the time of $\ll$HungTiNeiChing$\gg$ there was called "yateng", "yatong", "chiyaqutong", "kouchitong", "nichi", "chichong", "fengchi", "chongshitong", "chongshiyachi", "chifengzhongtong", "chiyinzhong", "yachuangzhongtong" 2. The Oriental Medical cause of Dentalgia are fire, wind, cold, blood stasis, stomach-heat, phlegm, difficiency of kidney, late snack, insect and wound, and then the Western Medical cause are cacodontia, periodontal disease, trigeminal nerve pain, stress 3. The meridians used for the treatment are large intestine, stomach, triple warmer, gallbladder and small intestine 4. The most frequently used acupuncture point for the treatment are Hapkok(LI3), Naejong(S44), Hyopko(S6), Igan(LI2), Sohae(H3), Yanggok(SI5), Hagan(S7), Taeyong(S5), Samgan(LI3), Kokehi(LI11) 5. The most frequently used moxibustion for the treatment are Sungjang(CV24), Yolgyol(L7), Kyonu(LI15), Taeyon(L9), Hapkok(LI3) 6. In the superior dental pain there commonly used the acupuncture point of stomach meridian, triple warmer meridian, gallbladder meridian in the inferior dental pain there commonly used the acupuncture point of large intestine meridian. 7. The most frequently used acupuncture point for the superior dental pain are Naejong(ST44), Yanggok(SI5), Chongnyong(G17), Kakson(TE20), In the inferior detal pain there are Taeyong(S5), Hapkok(LI3), Igan(LI2), Sangyang(LI1), Samgan(LI3) 8. In the treatment of dental pain The Acupuncture therapy utilized the division of region are the Erzhen therapy(耳針療法), the Touzhen therapy(頭鍼療法), the Shouzhen therapy(手鍼療法), the Zuzhen therapy(足鍼療法), the Bizhen therapy(鼻針療法), the Wanhuaizhen therapy 9. In dental pain the other therapy are the Taozhen therapy(陶鍼療法), the Pifuzhen therapy(皮膚針療法), the Dianzhen therapy(電鍼療法), the Yaozhen therapy(藥針療法).

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A literatual study on the Ecthyma (렴瘡에 對한 文獻的 考察)

  • Kim, Hee-Taek;Oh, Young-Seon;Rho, Sek-Seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.10 no.1
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    • pp.209-246
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    • 1997
  • In the literatual study on the Ecthyma, the results were as follows. 1. The pathogenic factors of Ecthyma is divided three parts. One is exogenous pathogenic factors which including the wind evil, wind heat and toxic material produced by wetness evil. Another is endogenous pathogenic factors which including the declination of kidney-yang, impairment of the liver and kidney, the lower classes of yin-fire, accumulation of wetness-heat in the spleen asthenia, impairment of the liver and kidney, wetness-heat of three yang, asthenic heat-syndrome of three yin. The other is pathogenic factors neither endogenous nor exogenous which including the food and living, uncontrol sexual excess, anxiety and angry, injury of skin, injury of insects and animals. 2. Five viscera which was concerned with Ecthyma are liver, spleen and kidney. 3. Frequent region of Ecthyma are S-36(足三里) and C-7(陰交). External Ecthyma was rose to wetness-heat of three yang channel that cured easily. Internal Ecthyma was rose to asthenic heat-syndrome of three yin channel that cured hardly. 4. In the frequency of prescription, the most numerous prescription is Bojungikgitang(補中益氣湯) and the next are Kyukgigo(隔紙膏) and Yukmijihwanghwan(六味地滉丸). 5. In the frequency of medicine, the most medicine is Calomelas(輕粉) which included Hydrargyrum(水銀) and the next are Olibanum(乳香) and Resina Commiphorae Myrrhae(沒藥) which regulating vital energy and pain control medicine used that in order to destroy insects and remove polson. 6. In classification of the medical action, medicine of clearing away summer-heat and heat evil and activating blood circulation to dissipate blood stasis used to be very busy which in order to remove the disorder of vital energy for virulent heat-evil. 7. In classification of four characters, the most part is warm medicine, the next are cold and cool medicine and there is a few that is hot medicine. 8. In classification of five tastes, the most numerous tastes are bitter and acrid, the next are sweet, salty and sour tastes. 9. In classification of virulence of medicine, the most part is non-toxic, the next are weakly and deadly poison. 10. In classification of channel distribution, the most is the medicine that belongs to liver channel, the next are the lung, spleen, stomach and kidney channel.

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Using Digital Climate Modeling to Explore Potential Sites for Quality Apple Production (전자기후도를 이용한 고품질 사과생산 후보지역 탐색)

  • Kwon E. Y.;Jung J. E.;Seo H. H.;Yun J. I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.6 no.3
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    • pp.170-176
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    • 2004
  • This study was carried out to establish a spatial decision support system for evaluating climatic aspects of a given geographic location in complex terrains with respect to the quality apple production. Monthly climate data from S6 synoptic stations across South Korea were collected for 1971-2000. A digital elevation model (DEM) with a 10-m cell spacing was used to spatially interpolate daily maximum and minimum temperatures based on relevant topoclimatological models applied to Jangsoo county in Korea. For daily minimum temperature, a spatial interpolation scheme accommodating the potential influences of cold air accumulation and the temperature inversion was used. For daily maximum temperature estimation, a spatial interpolation model loaded with the overheating index was used. Freezing risk in January was estimated under the recurrence intervals of 30 years. Frost risk at bud-burst and blossom was also estimated. Fruit quality was evaluated for soluble solids, anthocyanin content, Hunter L and A values, and LID ratio, which were expressed as empirical functions of temperature based on long-term field observations. AU themes were prepared as ArcGlS Grids with a 10-m cell spacing. Analysis showed that 11 percent of the whole land area of Jangsoo county might be suitable for quality 'Fuji' apple production. A computer program (MAPLE) was written to help utilize the results in decision-making for site-selection of new orchards in this region.