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Fire Resistance Behavior and Residual Capacity of Voided Slab Subjected to Fire According to Loading Condition (화재 시 하중 재하 조건에 따른 중공슬래브의 내화거동 및 잔존성능)

  • Choi, Hyun-Ki;Bae, Back-Il;Jung, Hyung-Suk;Choi, Chang-Sik;Choi, Joo-Hong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.1
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    • pp.99-106
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    • 2018
  • This study presents experimental investigation on the residual capacity of fire-damaged voided slabs according to loading conditions. In this study, two voided slab specimens were fabricated, and heated by ISO standard fire during 120 minutes with different loading conditions of presence of loading. These specimens were cooled down to room temperature, and the residual capacity of fire-damaged voided slabs was investigated. Based on test results, thermal distribution of voided slab through the depth of concrete sections is different by the loading conditions. The temperature of loaded specimen is rapidly elevated through the whole depth of concrete sections compared to the unloaded specimen. The residual strength of fire-damaged voided slab specimens are 60% and 66% of that of voided slab specimen without fire damage, and the residual stiffness of fire-damaged voided slab specimens decreases by 15%~23% of that of voided slab specimen without fire damage. In case of voided slab specimens subjected ISO standard fire, the loaded specimen shows the decrease of 10% in the residual strength and the decrease of 15% in the residual stiffness compared to the unloaded specimen. It seems to result from higher temperature of bottom reinforcements in the loaded specimen due to the cracks, and more extensive damage on concrete cover of reinforcements by spalling process according to load level.

A Prioritization Method Considering Trip Patterns to Introduce Short-turn Buses (단거리 순환버스 도입을 위한 통행패턴 기반의 우선순위 결정방법)

  • Moon, Sedong;Kim, Dong-Kyu;Cho, Shin-Hyung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.18 no.5
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    • pp.1-18
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    • 2019
  • A short-turn bus is a bus that is operated within a subsection of an existing bus line. Previous studies regarding short-turn buses decided optimal turn-back points for a single bus line rather than a bus network. Also, in-vehicle crowding which has a significant impact on transit convenience was rarely considered. Therefore, this study aimed to develop a methodology to set priorities for the introduction of short-turn buses of bus lines and sections, considering crowding. To achieve this objective, we calculated occupancies and crowding alleviation benefits of existing bus lines overlapping a new short-turn route based on transit card data, before and after the introduction of short-turn strategy. Also, operator and social costs caused by the introduction of short-turn buses were calculated. Those procedures were iterated over bus lines and sections to operate a short-turn service, and a section whose benefit-to-cost ratio (B/C) is the largest in a line was selected to operate a short-turn service in the line. After, priorities of bus lines to introduce short-turn services could be determined based on B/C values, and the optimum total fleet size could be determined when a short-turn strategy is applied in multiple lines.

Effect of 630 nm Light Emitting Diode (LED) Irradiation on Wound Healing in Streptozotocin-Induced Diabetic Rats

  • JeKal, Seung-Joo;Kwon, Pil-Seung;Kim, Jin-Kyung
    • Biomedical Science Letters
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    • v.16 no.4
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    • pp.365-376
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    • 2010
  • The purpose of this study was to clarify the effect of light emitting diode (LED) irradiation on healing of impaired wound and alteration of mast cells in experimental diabetic rats. Twenty-four male Sprague-Dawley rats were divided into four groups: excision (Ex), excision-LED irradiation (Ex-LED), diabetes + excision (DM) and diabetes + excision + LED irradiation (DM-LED). Diabetes was induced in rats by streptozotocin (STZ) injection (70 mg/kg, single dose) and 6 mm punch excision wounds were created on the back after shaving hair. The LED-irradiated rats were treated to a daily dose of $5\;J/cm^2$ LED (630 nm) light for 11 days after surgery, and were killed at day 1, 3, 7 and 11. The lesion and adjacent skin tissues were excised, fixed with 10% buffered formalin and embedded with paraffin. For evaluation of wound healing, hematoxylin-eosin (HE) and Masson trichrome staining were performed. Mast cells (MCs) were stained with toluidine blue (pH 0.5) and quantified using a computerized image analysis system. The proliferation activity of keratinocyte in skin tissues was analyzed on sections immunostained with proliferative cell nuclear antigen (PCNA). The results showed that wound healing rate, collagen density and neo-epidermis length, number of PCNA-positive cells, fibroblasts and mast cells were significantly higher in the LED-irradiated rats than in the DM and Ex rats throughout the periods of experiment. Exceptionally, the number of MCs was significantly lower at day 11 compared with day 7 after surgery in the all groups. These findings suggest that the LED irradiation may promote the tissue repair process by accelerating keratinocyte and fibroblast proliferation and collagen production in normal rats as well as in diabetic rats, and MCs may play an important role at an early stage of skin wound healing in normal and diabetic rats.

A study on the work environment and accident exposure status of Tower Crane workers (타워크레인 작업 근로자의 작업환경과 사고 노출 실태에 관한 연구)

  • Choi, Seo-Yeon;Cho, Kee-Hong;Park, Dong-Hyun;Choi, Byung-Gil
    • Journal of the Korea Safety Management & Science
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    • v.17 no.3
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    • pp.115-123
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    • 2015
  • The study conducted statistical analysis of survey on the 239 workers participating in national Tower Crane installation/dismantlement in order to identify work environment and health hazard exposure of Tower Crane workers. Consequently for work related safety status of Tower Crane workers, the number of installation/dismantlement work was the highest at 15-20 times per month, and safety equipments were not arranged at work and they felt highly anxious when boarding on the Tower Crane. Furthermore, it is found that they feel anxious working in the influence of the weather, noise, vibration, wind, the sun ray, and structure characteristic. They have very low satisfaction in the insecureness of workplace and the work environment, and recognizes that their work affect highly on the health. 81.6% of workers have experienced accident at work, the cause of accidents were mainly due to poor work environment, and the health abnormality they have experienced were mostly fatigue and concentration reduction. For job stress, job demand and conflict in relationship were the highest sections. Total 66.5% of workers complained of musculoskeletal disorder related subjective symptom, and back pain patients were the highest of all groups.

The Study of the Origin and Transformation of the Arts of the Dao in The Canonical Scripture (《典經》中的道術思想來源與轉化運用研究)

  • Hsieh, Tsung-hui
    • Journal of the Daesoon Academy of Sciences
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    • v.36
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    • pp.267-298
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    • 2020
  • The purpose of the paper is to analyze the developmental background and practical approaches to the arts of the Dao (道術 dosul) in Daesoon Jinrihoe (大巡真理會) by tracing this concept back to its source and comparing and contrasting Daesoon Jinrihoe's usage of 'arts of the Dao' with the usage found in traditional Daoism. The paper is divided into a preface, conclusion, and two body sections. Especially significant discoveries appear in the second and third sections. In the second section, the Daoist concept of Alterable and Unalterable Degree Numbers (運度定數 yundudingshu, 'degree numbers' suggesting 'fate' or 'destiny') allows for a comparison between the Reordering Works of Heaven and Earth (天地公事 cheonjigongsa) from Daesoon Jinrihoe's The Canonical Scripture (典經 jeon-gyeong) and the Opening of Calamities to Save Humanity (開劫度人 kaijieduren) in Daoism. Here discourse can be provided regarding the cause of calamities (劫 'jie' in Chinese and 'geop' in Sino-Korean). Additionally examined are the deep grievances between divine beings and humans and the cosmic cycles of growth and decay as both of these relate to the reason for calamities. As for the resolving of calamities, there are two differing perspectives proposed by Daesoon Jinrihoe and traditional Daoism. Daesoon Jinrihoe believes that Kang Jeungsan (姜甑山) led changes and renewal through the Reordering Works of Heaven and Earth. In this context, clergy and laity play roles as assistants. However, Daoism emphasizes gaining merit from the recitation of scriptures and the collective participation of immortals rather than relying completely upon divine intervention from the Celestial Worthy of the Primordial State (元始天尊 yuanshi tianzun). In the third section, 'The Origin and Application of the Arts of the Dao (道術 daoshu),' analysis is provided regarding the origin and connotation of five directional generals (五方將 wufangjiang), the twenty-four generals (二十四將 ershijiang), the twenty-eight generals (二十八將 ershibajiang), and the forty-eight generals (四十八將 sishibajiang). Likewise examined is the relationship between the arts of the Dao in The Canonical Scripture and Thunder Rites in the Shen Xiao Lineage (道教神霄雷法 daojiao shenxiao leifa) of Daoism. Lastly, some points are made about the operation of two ceremonies: The Ceremony of Transformation and Pacing (遁甲步罡儀式 dunjiabugangyishi) and Divination through the Formula Disc of the Six Ren Gods (六壬式盤占卜 liuren shipanzhanbu).

Ultrastructural Change of the Bile Duct Fibroblast at Infected Rat with Clonorchis sinensis (간흡충에 감염된 실험쥐 담관 섬유모세포의 미세구조적 변화)

  • Kim, Soo-Jin;Min, Byoung-Hoon
    • Applied Microscopy
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    • v.34 no.2
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    • pp.121-130
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    • 2004
  • In this study, ultrastructural change of the bile duct fibroblast at infected rat with Clonorchis sinensis, and the distribution of lectin receptors and actin protein in cultured bile duct infected with Clonorchis sinensis. It explored using colloidal gold label complex with lectin WGA purified from wheat germ (Triticum vulgaris) and anti actin antibody purified actin (43 kDa) isolated from chicken back muscle. The lectin WGA with protein A gold complex labeled sections of the cultured fibroblast revealed gold particles specifically distributed on the multi vesicular form Golgi complex and cell surface of the fibroblast. The actin antibody with protein A gold complex labeled sections of the cultured fibroblast revealed gold particles specifically distributed on the cytoplasm of the fibroblast. Labeling of cultured fibroblast in rat bile duct infected with Clonorchis sinensis was then quantified and compared to that of cultured Fibroblast in Rat Bile duct. These results indicate that lectin WGA receptors are located in the multi vesicular form Golgi complex in the cytoplasm to the cytoplasmic process of the Rat bile duct fibroblast infected with Clonorchis sinensis. Therefore, the GlcNAc and NeuNac regions on the cell surface and cytoplasmic process appear to be functionally associated with cell-recognition and protection from other cell of the tissue, and linked with secretion and exocytosis of the fibroblst cytoplasm. GlcNAc and NeuNAc product in the multi vesicular form Golgi complex then it is transported to cell surface. Actin protein is many appears that infected fibroblast rather than normal fibroblast. The fibroblast of infected with Clonorchis sinensis are against of the physical and chemical stimulation. Then development of cytoplasmic process is relative some stimulation.

The Development of Men's Dress Form for Pattern Making (패턴메이킹을 위한 남성(男性) 인대개발(開發)에 관(關)한 연구(硏究))

  • Yoo, Hyun;Shim, Boo-Ja
    • Journal of Fashion Business
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    • v.10 no.5
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    • pp.159-179
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    • 2006
  • This research checked about the necessity for the development of men's dress forms in the first investigation for the educational circle and the men's wear industry. Somatotype characteristics were analyzed in the second investigation of body measurement with the subjects of 200 male adults in their twenties residing in Busan. The following are the results of the present research to develop male dress forms for patternmaking: 1. In the group analysis for the characterization of front body types, three somatotypes were found and named H, Semi X, and Y. In the cluster analysis of side body types, four types were identified: D, I, d, and q. In the combination of front and lateral body types, four kinds were chosen: semi X-I, semi X-q, semi Y-I, and Y-q. 2. Through the comparison of plane figures by the plaster method as well as horizontal and vertical cross sections by the sliding gauge method, semi X-I was finally chosen as the standard somatotype for male dress form development. 3. Compared with the sliding gauge method of the present dress forms, the research dress form reflected better the shapes of the parts of the back and hips and the position of the waist, especially for males in their 20's. In addition, the dress form in the current research had superior points in all the items of clothing evaluation. Based on the above results, the sizes and models of the men's dress forms for patternmaking were developed.

Relations Between Impact Damage and Ply Angle Under Same Impact Energy Condition (同一한 衝擊에너지 條件下의 CFRP 斜交積層板의 衝擊損傷과 配向角의 關係)

  • ;笠野英秋
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.10
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    • pp.1824-1832
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    • 1992
  • This study investigated the compressive Young's modulus and the impactinduced damage of CFRP angle-ply laminate under same impact energy condition. The specimens of angle-ply laminate composites [0.deg.$_{6}$/ .theta..deg.$_{10}$/ 0.deg.$_{6}$] with .theta..deg. =30.deg., 45.deg., 60.deg. and 90.deg. were employed, and damaged by steel balls of diameter of 5mm and 10mm propelled by air gun type impact testing machine. The impact damaged zones were observed through a scanning acoustic microscope(SAM), and their cross-sections were observed through a scanning electron microscope(SEM). The compressive Young's moduli before and after impact were measured, and compared with the theoretical values calculated. The results obtained were as follows: (1) The damage areas on the interfacial boundaries showed more severe change on the back side interface than on the impact side interface with increasing ply-angle. (2) The damage areas on the interfacial boundaries became larger with increasing impact velocity or ply-angle. (3) The impact damaged zone showed the delamination on the interfacial boundaries and transverse cracks inside laminas. (4) The impact damaged zone was affected by the impactor size and speed or ply-angle under same impact energy condition. (5) Compressive Young's moduli before and after impact were lower than theoretical value, but showed a similar change according to ply-angle. (6) Compressive Young's moduli after impact were higher than those before impact, but there was no remarkable change in apparent compressive modulus after impact.t.act.

Effects of Electrical Stimulation on Wound Healing and Skin Mast Cells in Streptozotocin-Induced Diabetic Rats (스트렙토조토신 유도 당뇨 흰쥐에서 전기자극이 상처치유와 피부 비만세포에 미치는 영향)

  • Jekal, Seung-Joo;Lee, Kyung-Sun;Chung, Ok-Bong;Lee, Jae-Hyoung
    • Korean Journal of Clinical Laboratory Science
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    • v.40 no.2
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    • pp.118-128
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    • 2008
  • The aim of this study was to investigate the effect of electrical stimulation on healing of impaired wound and alteration of mast cells in experimental diabetic rats. Thirty male Sprague-Dawley rats were divided into three groups : incision (control), diabetes+incision (diabetes) and diabetes + incision + electrical stimulation (D/ES). Diabetes was induced in rats by streptozotocin (STZ) injection (60 mg/kg, one time) and 20 mm length incision wounds were created on the back after shaving hair. The electrical stimulation rats were treated with a current intensity of 30~50 V at 120 pps and $140{\mu}s$ for 10 days from 3 days after STZ injection. The lesion and adjacent skin tissues were fixed with 10% buffered formalin, embedded with paraffin. For wound healing analysis, hematoxylin-eosin (HE) and picrosirius red staining were performed. Mast cells (MC) were stained with toluidine blue (pH 0.5) and quantified at ${\times}200$ using a light microscope. The density of keratinocyte proliferation and microvessels in skin tissues were analyzed using a computerized image analysis system on sections immunostained with proliferative cell nuclear antigen (PCNA) and ${\alpha}$-smooth muscle actin (${\alpha}$-SMA), respectively. The results showed that the wound healing rate, collagen density and neoepidermis thickness, density of PCNA-positive cells and density of ${\alpha}$-SMA-positive vessels were significantly higher in D/ES rats than in diabetic rats. The density of MCs and degranulated MCs in D/ES rats were also significantly higher than those in diabetic rats. These findings suggest that the electrical stimulation may promote the tissue repair process by accelerating collagen production, keratinocyte proliferation and angiogenesis in the diabetic rats, and MCs are required for wound healing of skin in rats.

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Positive Effects of Diphlorethohydroxycarmalol (DPHC) on the Stability of the Integument Structure in Diet-Induced Obese Female Mice

  • Kim, Chae-lim;Cha, Sun-yeong;Chun, Min Young;Kim, Bumsoo;Choi, Min Young;Cheon, Yong-Pil
    • Development and Reproduction
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    • v.19 no.3
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    • pp.145-152
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    • 2015
  • Diphlorethohydroxycarmalol (DPHC) is a known to modulate the expression of extracellular matrix (ECM) components in 3T3-L1. However, the possible role of DPHC in integument stability during obesity induction is not clear yet. We evaluated the effects of DPHC on collagen or elastic fiber quantity in integument during obesity induction with high-fat diet. The dorsal back integument sections were stained with hematoxylin-eosin, Masson trichrome, and Verhoff-Van Gieson. The intensities of collagen fibers and elastin fibers were analyzed with ImageJ. The number of fibroblasts was counted at ${\times}1,000$ fields. The number of fibroblast was increased by obesity induction, but DPHC suppressed it in a concentration-dependent manner both in lean and obese mice. On the other hand, the intensities of collagen fibers were increased by DPHC treatment in obese mice groups but not in lean mice groups. The intensities of collagen fibers of obese mice were lower than that of the lean mice in 0% group. However, the number became similar between lean and obese mice by the treatment of DPHC. The intensity of elastic fibers was increased in the lean mice with the concentration of DPHC. In the obese mice group, there were increasing patterns but only significant at 10% DPHC group. The intensity of elastic fibers of obese mice was higher than lean mice in 0%, 1%, and 10% groups. Histologically epithelial cells and follicle cells which were diffused nuclear staining forms were increased by DPHC treatment. The results suggest that the activity of integument cells during obesity induction can be modulated by DPHC.