• Title/Summary/Keyword: local erosion

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A study on the relationship between the thermal properties of rock and the enviroment in underground spaces (암반 열물성과 지하공간 환경분석 연구)

  • Lee, Chang-Woo
    • Tunnel and Underground Space
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    • v.6 no.4
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    • pp.335-341
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    • 1996
  • This fundamental study analyzes the relationship between rock thermal properties and psychrometric properties in underground space and has a ultimate goal to develope technologies for predicting major environmental variables. The study is divided into 2 subjects (1) developement of a basic model for predicting temperature and humidity, (2) analysis of the validity of the model through application to a local underground storage space for military supplies. The basic model is built for the network of tunnel-shaped underground spaces. The model takes into account rock thermal properties and changes in moisture content in the air due to condensation/evaporation on the rock surface. Using lumped-parameter analytical method, heat flux from or to the surrounding rock is calculated and then the psychrometric properties(air quantity, pressure, temperature, humidity) are estimated through network simulation. The model can be utilized regardless of the tunnel type. The study site is a local storage space built in rock, mainly granite gneiss and quartz-porphyry. It is a U-shaped tunnel, 593.5m long and 6x6.5m wide. Relative humidity inside has to be strictly controlled under 55% to avoid erosion of a certain types of supplies stored in 6 chambers with the capacity of 300~1.000 ton. The thermal conductivity varies between 2.734 and 2.779W/m$^{\circ}C$ and the thermal diffusivity is in the range of 1.119 and $1.152{\times}10^{-6}\;m^2/s$ the specific heat between 910 and $920\;J/kg^{\circ}C$. Relative errors of the predicted values of dry/wet temperature and relative humidity are 0.8~3.0%, 0~7.5% and 0~7.0%, respectively. Apparent errors associated with the rock surface temperature seems to be partly due to the intrinsic limitations in the infrared thermometer used in this study.

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A Case of the Inverted Papilloma of the Nose and Paranasal Sinuses (비강 및 부비동에 발생한 반전성 유두종 1례)

  • 권혁진;박호선;윤병용
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1982.05a
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    • pp.15.2-15
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    • 1982
  • Inverted papilloma arising from mucous membrane of the nasal cavity and paranasal sinuses is very rare benign neoplasm. Ward first described nasal papilloma in 1854, but its infrequent occurrence has delayed accurate understanding. This tumor was histologically benign neoplasm and clinically malignant, because it is locally invasive with extensive bone erosion at times and it shows a high incidence of local recurrence, and change of squamous cell carinoma was sometimes found. Recently, the authors have experienced a case of inverted pailloma with focal squamous cell carcinoma change which occupied the right side of the nsal cavity and maxillary sinus in a 48-year-old male. The tumor mass was removed surgically through intranasal and Caldwell-Luc's approach, and then was treated with systemic administration of Bleomycin, local spray of 5-FU and radiotherapy ($Co^{60}$). We report our case with review of current literatures.

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A Study on Meayres to Minimize Human Damage in Natural Disaster Vulnerable Areas (자연재해 취약지역 인명피해 최소화 방안에 관한 연구)

  • Seo, Jung Pyo;Cho, Won Cheol
    • Journal of Korean Society of Disaster and Security
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    • v.7 no.1
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    • pp.17-25
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    • 2014
  • Due to the recent climate change impact, natural disasters occur due to sea surface rising, typhoon attacks, flash floods, local heavy rainfalls, landslides, and coastal area erosion, continuing to cause human and property damage. These impacts, coupled with urbanization and industrialization activities, are turning the previously safe areas into disaster-vulnerable areas, increasing human and economic damage. This paper aimed to prepare measures designed to minimize human damage in natural disaster vulnerable parts of South Korea in summer. Toward that end, how vulnerable areas were managed and what the damage was like were studied. Also, cases of human damage and statistics there of were reviewed and analyzed, relevant problems were derived, and thus structural and non-structural measures designed to minimize human damage were presented.

THE CONTROL METHOD OF CONTINUOUS GINGIVAL BLEEDING IN A DISABLED PATIENT WITH BLEEDING DISORDER : REPORT OF A CASE (출혈성 장애환자에서 지속적인 치은출혈시 지혈법 : 증례보고)

  • Son, Jeong-Seog;Oh, Ji-Hyeon;Yoo, Jae-Ha;Kim, Jong-Bae
    • The Journal of Korea Assosiation for Disability and Oral Health
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    • v.10 no.1
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    • pp.31-37
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    • 2014
  • The general local cause of gingival bleeding is the vessel engorgement and erosion by odontogenic infection. Abnormal gingival bleeding is also associated with systemic causes. Bleeding disorders in which continuous gingival bleeding is encountered include the followings : vascular abnormalities, platelet disorders, hypoprothrombinemia and other coagulation defects. There are classic methods for gingival bleeding control, such as, direct pressure, electrocoagulation, suture, crushing and application of hemostatic agents. If the continuous gingival bleeding is not stopped in spite of the conventional methods, the life of patient is threatened owing to upper airway obstruction, syncope, vomiting and hypovolemic shock. Therefore, the rapid and correct hemostatic method is very important in the emergency condition. This is a case report of continuous gingival bleeding control by primary endodontic drainage & suture in a disabled patient with systemic bleeding disorders.

The Economic Valuation of Ecosystem Restoration in Suncheon Bay (순천만 생태복원에 따른 경제적 가치 평가)

  • Hwang, Minsup;Lee, Myung Kyoon;Jung, Tae Yong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.17 no.4
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    • pp.69-79
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    • 2014
  • Coastal wetlands are among the most productive biomes in the Earth. The economic values include the direct use of a coastal wetland's ecosystem services, such as food, raw materials, recreation, and tourism. Other values comprise the indirect use of a coastal wetland's ecosystem services, such as carbon sequestration, waste-water treatment, and erosion prevention. In particular, Suncheon Bay is recently attracting attention as the most successful case of the preservation and restoration. This study applies Travel Cost Method (TCM) to estimate the economic value by drawing the demand curve for trips to Suncheon Bay. The TCM is an approach used for economic valuation of non-market goods and services. Based on the results of TCM, this study shows that the economic benefit from recreational uses of the site adds up to \174.7 billion per year. It is also significant in the sense that monetary information is suggested to help local policy makers evaluate the realistic values of coastal wetlands.

A Study on the HAE UN DAE Beach Deformation Caused by the Construction of a Sea Wall (해운대 해수욕장 침식에 미치는 해안제방의 영향에 대하여)

  • Mun, Byeong-Hyeong;Kim, Ga-Ya;Lee, Seung-Hwi
    • Water for future
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    • v.17 no.3
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    • pp.197-209
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    • 1984
  • This study has been carried out to investigate into the local scour of wall-toe and the beach deformation caused by the construction of a seal wall. It has been performed to determine the values of the marine invertigation of HAE UN DAE and two dimensional Movable bed gydraulic model test. From the results of this work approtection method of HAE UN DAE beach erosion is established to reduce the amount of topography deformation by investigating the values of the constructive position of a sea wall, seabed slope, the maximum scour depth, the first and the second influence range, the maximum quantity of beach deformation, and the distance measured from the sea will to the maximum quantity of beach deformation.

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Paraquat Poisoning by Skin Absorption (파라콰트에 의한 피부 손상의 임상적 고찰)

  • Yang Jong Oh;Gil Hyo Wook;Lee Eun Young;Hong Sae Yong
    • Journal of The Korean Society of Clinical Toxicology
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    • v.2 no.2
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    • pp.101-105
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    • 2004
  • Purpose: Paraquat is the most commonly used herbicide in Korea. Exposure to paraquat through the skin has resulted in local irritation or inflammation of varying degree, sometimes severe. The purpose of this study was to review the patients with paraquat poisoning by skin absorption. Methods: We analysed retrospectively the clinical and laboratory findings of 45 patients with paraquat poisoning after dermal exposure, who were admitted to Soonchunhyang University Cheonan Hospital from January 1999 to December 2003. Results: Among 870 cases of paraquat poisoning, 45 cases were exposed to paraquat through the skin. The peak incidence was the fifth decade($40\%$). The clinical symptoms were pain, pruritus, nausea, and vomiting. The major skin lesions were generalized vesicobullae and necrotic erosion in face, scrotum, trunk, upper and lower extremities and etc. All patients were survived after skin contact or inhalation of paraquat. Conclusion: This study illustrates the extreme toxicity of paraquat and demonstrates that lethal quantities of paraquat may be absorbed if repeated exposure to it. Stricter precautions, including the mandatory use of protective clothing, should be recommended whenever this material is used.

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Failure Assessment and Strength of Steam Generator Tubes with Wall Thinning (증기발생기 전열관 감육부의 강도 및 손상평가)

  • Seong, Ki-Yong;Ahn, Seok-Hwan;Yoon, Ja-Moon;Nam, Ki-Woo
    • Journal of Ocean Engineering and Technology
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    • v.21 no.2 s.75
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    • pp.50-59
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    • 2007
  • Steam generator tubes are degraded from wear, stress corrosion cracking, rupture and fatigue and so on. Therefore, the failure assessment of steam generator tube is very important for the integrity of energy plants. In the steam generator tubes, sometimes, the local wall thinning may result from severe degradations such as erosion-corrosion damage and wear due to vibration. In this paper, the elasto-plastic analysis was performed by FE code ANSYS on steam generator tubes with wall thinning. Also, the four-point bending tests were performed on the wall thinned specimens, and then it was compared with the analysis results. We evaluated the failure mode, fracture strength and fracture behavior from the experiment and FE analysis. Also, it was possible to predict the crack initiation point by estimating true fracture ductility under multi-axial stress conditions at the center of the thinned area from FE analysis.

5-SRICOS Method : Prediction of Scour Depth Around Bridge Piers in Cohesive Soils (S-SRICOS 방법 : 점성토지반의 교각세굴깊이 예측)

  • 곽기석
    • Journal of the Korean Geotechnical Society
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    • v.18 no.2
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    • pp.13-21
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    • 2002
  • A new method called S-SRICOS is proposed to predict the local scour depth around bridge piers. The S-SRICOS method is a simplified version of the SRICOS method which was developed to predict the scour depth versus time curve around bridge piers. The SRICOS method which considers the time effect based on the soil properties and the hydraulic parameters can handle a multi-flood hydrograph and multi-layer soil systems with the SRICOS program. An attempt was made to simplify the method to the point where only hand calculations would be required. The concept of the equivalent time was developed leer this purpose. The S-SROICOS method requires only 4 parameters such as pier width, design bridge life, design velocity corresponding to the design bridge life, and initial scour rate of the soil. The S-SRICOS method was verified against 55 cases of the scour depth results using the SRICOS method.

A Study on the Recognition of Defected Fingerprint Using Chain Code (체인 코드를 이용한 훼손된 지문의 인식에 관한 연구)

  • 조민환
    • Journal of the Korea Society of Computer and Information
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    • v.8 no.4
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    • pp.63-68
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    • 2003
  • Almost the system are usually taken by means of shapes and positions of ridge's end-points and bifurcation in the fingerprint recognition. but we studied about recognition of polluted fingerprint by chain code ridges. the results and sequence of processing are summarized as follows. (1)Capture several kinds of polluted fingerprint image. (2)Preprocessing(median filtering for removing noises, local and global histogram equalization, dilation and erosion, thinning and remove pseudo image), (3)Rebuild ridge line after Least Square Processing, (4)Compute distribution of chain code vector, (5)The results are almost same values of each vector of preprocessed fingerprint images. From the results, we can surmised more successful fingerprints recognition system in combination with other system by singular points

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