• Title/Summary/Keyword: 목두께

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Performance Comparison of Korean Tongue and Groove Joint between Hand-made and Pre-cut (주먹장 접합부의 수가공과 기계가공의 성능비교)

  • Kim, Gwang-Chul;Kim, Jun-Ho
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.5
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    • pp.664-676
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    • 2016
  • Recently, the demand on the Hanok have been increased with social change. However, Hanok has a major problem of a rising costs caused by hand-made process. So, performance comparison between hand-made process and pre-cut process was conducted to modularize the joints in Hanok. Douglas-fir was used to manufacture the structural size dovetail joints by hand-made and pre-cut precess. The bending strengths on joints with two process were evaluated. The average ultimate load of pre-cut joints was 1.5 times higher than that of hand-made joints. F-test results in both process showed a great relationships between ultimate load and tenon's size variation. The length and thickness of tenon showed a proportional relationship with the ultimate load, but the tenon width showed inverse proportion with the ultimate load. This results may be used as basic data for the joint modularization of Hanok.

A case report of Cheyletiella infestation on a Whippet dog in Korea (Whippet종 개에서의 Cheyletiella yasguri(진드기목: 발톱진드기과) 감염증례 보고)

  • 신성식
    • Parasites, Hosts and Diseases
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    • v.34 no.4
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    • pp.267-278
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    • 1996
  • A clinical case of CheMletietlo infestation on a dog born and raised in Korea is reported. A three-year old female Whippet was hospitalized due to a multiple fracture and displacement of the left scapula caused by a recent car accident The mite infestation was not noticed at the time of hospitalization. The dog underwent multiple operations involving internal fixation of the fractured scapula with wire and a plate, followed by extensive chemotherapy with antibiotics and prednisolone. After two months of hospitalization. a pruritic dermatitis near the left scapula developed. Multiple white dandruff-like ilakes were seen on the hair coat. especially over the dorsal spine and neck, and the dog expressed increased pruritus by frequently licking and scratching the affected areas. Local dense accumulations of skin debris that became crusty were also observed. Microscopic examination or a skin scraping revealed a heavy infestation of cheyletiella vnsfuri. as idrntified by the prrsrnce of holes of the palpi and the heart-shaped sensory organ on menu I. Immnosuppression elicited by the extensive administration of prednisolone was suspected for the initiation of the generalized mite infestation.

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Finite Element Analysis on the Stress and Deformation Behaviors of a Safety Helmet (안전헬멧의 응력 및 변형거동에 관한 유한요소해석)

  • Kim, Chung-Kyun
    • Journal of the Korean Institute of Gas
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    • v.13 no.4
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    • pp.27-32
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    • 2009
  • This paper presents the stress and deformation behaviors using the finite element method as a function of the thickness of the helmets without the bead frames on the top of the shell structure. The helmet that would provide head and neck protections without causing discomfort to the user when it was worn for long periods of time should be manufactured for increasing the safety and impact energy absorption. The FEM computed results show that when the impulsive force is applied on the top surface of a helmet, the maximum stress and strain have been occurred around the position of an applied impact force, which may lead to the initial failure on the top surface of the helmet shell. As the helmet thickness is decreased from 4mm to 2mm, the impact energy absorbing rate is radically increased, and the maximum stress of the helmet is increased over the tensile strength, 54.3MPa of the thermoplastic material. Thus, the top surface of the helmet should be supported by a bead frame and increased thickness of the shell structure.

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A Study on the Strength of the Helmets with a Lobe in the Summit (정상 돌출부를 갖는 안전모의 강도 안전성에 관한 연구)

  • Kim, Chung Kyun
    • Journal of the Korean Institute of Gas
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    • v.17 no.5
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    • pp.37-41
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    • 2013
  • This paper presents the strength safety of stress and deformation behaviors using the finite element method as a function of the thickness of the protective helmets with and without an extruder on the top of the shell structure. The helmet that would provide head and neck protections without causing discomfort to the user when it was worn for long periods of time should be manufactured for increasing the safety and impact energy absorption. The stress analyzed results show that when the impulsive force of 4,540N is applied on the top surface of a helmet, the safe thickness is 3.7mm for the conventional helmet and 3.2mm for the modified new helmet. Based on the deformation analysis, the FEM results recommend that the safe thickness is 3.2mm for the conventional helmet and 2.0mm for the modified new helmet. Thus, it may be more safe design of the helmet, which has an extruded structure on the summit surface of the helmet.

Observation on Neck Form Changes Related to Aging in Men(Part I) -Using the Sliding Gause Measurement Method- (성인남자 목부위의 연령별 형태변화에 관한 연구(제1보) -슬라이딩 게이지법에 의한 분석-)

  • 이영숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.2
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    • pp.252-262
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    • 1994
  • As a means to get a better understanding of the kind of form changes to which is subject the neck of the men, in its aging process, several measurement recordings on a vertical and horizontal sections were carried. Subjects were young, middle aged and elder men (15 in their twenties, 11 in their forties and again 11 in their sixties) 1) The analysis of the meansurement results led us to distinguish 3 types of subjects according to the position of the their Adam's apple with regard to the horizontal plane containing their 7th cervical vertebrae point : clearly above (Type I), next to(Type II), clearly below(Type III). We found that young men correspond to the Type I and II, middle aged men to the Type ll and 111 and elder men only to the Type III. 2) The comparison of the horizontal sectional surface contained in the planes corresponding to the 4 points, shows a larger sectional surface for elder men in the Adam's apple plane, accompanied by a change of position of the Adam's apple forwards. As for the front neck point plane, the body sectiolial surface is larger in depth in elder men, without much change in breadth. And for the acromion point plane, we observed also an increase in depth, but with a decrease in breadth corresponding partially to the atrophy of the thoraric cage in eldermen.

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The Clinical Significance of Bioelectrical Impedance Analysis for The Diagnosis of Obesity on Elementary Students (초등학교 아동의 비만 진단에 있어서 생체 전기저항 분석법의 의의)

  • Choi, Ki-Cheol;Ahn, Young-Jun;Yang, Eun-Seok;Park, Sang-Kee;Park, Jong;Moon, Kyung-Rye
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.1 no.1
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    • pp.107-114
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    • 1998
  • Purpose: The purpose of our study is to provide useful information for me-asurement methods of childhood obesity and to provide clinical significance of bioelectrical impedance analysis. Methods: We measured height, weight, waist to hip ratio, skinfold thickness and bioelectrical impedance from 206 elementary students in Kwangju from May to July 1997. Results: In males; 1) There were statistically high correlations between tri-ceps skinfold thickness and body mass index (BMI), percentage of body fat (%BF), weight, Rohler index (RI), total fat weight (TFW), waist to hip (W/H) ratio, height, lean body mass (LBM) (all, p<0.001). 2) There were statistically high correlations between subscapular skinfold thickness and BMI, RI, weig-ht, %BF, TBW (all, p<0.001). 3) There were statistically high correlations between %BF and BMI, triceps skinfold thickness, RI, TFW, subscapular skinfold thickness, weight (all, p<0.001). In females; 4) There were statistically high correlations between triceps skinfold thickness and BMI, weight, LBM, height, %BF (all, p<0.001). 5) There were statistically significant correlations between subscapular skinfold thickness and BMI, weight, LBM, RI, height. 6) There were statistically high correlations between percentage of body fat and BMI, RI, triceps skinfold thickness. The percentage of body fat according to the bioelectrical impedance analysis highly correlated with that calculated by skinfold thickness in males (r=0.57, p<0.01) and in females (r=0.30, p<0.01). Conclusion: The results of our study suggests that bioelectrical impedance analysis is a useful method of estimating body fat in the childhood obesity.

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Impact of Computed Tomography Slice Thickness on Intensity Modulated Radiation Therapy Plan (전산화단층촬영 슬라이스 두께가 세기변조방사선치료계획에 미치는 영향)

  • Lee, Seoung-Jun;Kim, Jae-Chul
    • Radiation Oncology Journal
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    • v.24 no.4
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    • pp.285-293
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    • 2006
  • $\underline{Purpose}$: This study was to search the optimal slice thickness of computed tomography (CT) in an intensity modulated radiation therapy plan through changing the slice thickness and comparing the change of the calculated absorbed dose with measured absorbed dose. $\underline{Materials\;and\;Methods}$: An intensity modulated radiation therapy plan for a head and neck cancer patient was done, first of all. Then CT with various ranges of slice thickness ($0.125{\sim}1.0\;cm$) for a head and neck anthropomorphic phantom was done and the images were reconstructed. The plan parameters obtained from the plan of the head and neck cancer patient was applied into the reconstructed images of the phantom and then absorbed doses were calculated. Films were inserted into the phantom, and irradiated with 6 MV X-ray with the same beam data obtained from the head and neck cancer patient. Films were then scanned and isodoses were measured with the use of film measurement software and were compared with the calculated isodeses. $\underline{Results}$: As the slice thickness of CT decreased, the volume of the phantom and the maximum absorbed dose increased. As the slice thickness of CT changed from 0.125 to 1.0 cm, the maximum absorbed dose changed ${\sim}5%$. The difference between the measured and calculated volume of the phantom was small ($3.7{\sim}3.8%$) when the slice thickness of CT was 0.25 cm or less. The difference between the measured and calculated dose was small ($0.35{\sim}1.40%$) when the slice thickness of CT was 0.25 cm or less. $\underline{Conclusion}$: Because the difference between the measured and calculated dose in a head and neck phantom was small and the difference between the measured and calculated volume was small when the slice thickness of CT was 0.25 cm or less, we suggest that the slice thickness of CT should be 0.25 cm or less for an optimal intensity modulated radiation therapy plan.

Studies on the Structure of Forest Community at Myungsunbong. Tokp'yongbong Area (지리산국립공원 명선봉, 덕평봉지역의 산림군집구조에 관한 연구 -구상나무군집-)

  • 추갑철
    • Korean Journal of Environment and Ecology
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    • v.13 no.4
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    • pp.299-308
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    • 2000
  • 지리산국립공원의 명선봉(1.586m)에서 덕평봉(1.521m)에 이르는 아고산지대를 중심으로 분포하고 있는 한국특산종 구상나무의 생육현황과 구상나무가 분포하는 천연림의 군집구조를 정확히 파악하여 앞으로 구상나무 관리의 기초자료를 마련하고자 구상나무가 생육하고 있는 지역에 26개의 방형구(20m$\times$20m)를 설치하여 식생을 조사하였다 분석한 결과 조사대상지는 신갈나무-구상나무 군집이었다 수종간의 상관관계에서는 뽕잎피 나무와 철쭉 마가목과 산벚나무, 층층나무와 시닥나무 등의 종들간에는 높은 정의 상관관계가 인정되었고 신갈나무와 쇠물푸레나무 잣나무와 노린재나무 등의 수종들간에 높은 부의 상관관계가 인정되었다 본 조사지의종다양도는 1.0572-1.0931로 비교적 낮은 편이었다. 구상나무의 활력은 저조한 것으로 나타났으며 8.32%가 고사목이었다 구상나무의 생육현황표에 의한 점수 평균은 9.03이었다 구상나무의 생육현황표에 의한 점수는 해발고와 낙엽퇴의 두께와 정의 상관관계가 인정되었다.

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Study on Stress Waves for Development of Glulam from Domestic Small Diameter Log(I) - Effect of MC on Stress Wave in Glulam Member - (국산 소경재를 이용한 집성재 개발을 위한 응력파 연구(I) - Glulam 부재의 응력파에 대한 함수율 영향 -)

  • Cha, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.3
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    • pp.90-100
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    • 1996
  • 두께가 20mm 와 30mm 이고, 폭이 40mm 와 60mm인 600mm 길이의 낙엽송 제재목에 응력파 시험을 실시하였다. 모든 시험편은 생재 상태로 구입 후 함수율 27%, 22%, 17%과 12%조건으로 조습 처리하였다. 함수율 변화에 따른 응력파 속도와 영계수를 구하기 위한 응력파 시험을 4종류의 함수율 조건에서 실시하였다. 응력파 속도와 응력파 시험으로부터 구한 영계수는 시편의 함수율, 치수, 그리고 시험편의 옹이와 옹이 주변 목리의 상호작용에 의해 영향을 받았다. 모든 함수율 및 각 함수율 조건에서 응력파 속도는 응력파에 의해 구한 영계수와 양호한 상관관계를 나타냈다. 응력파 속도와 응력파 시험으로 구한 영계수는 함수율이 증가할 때 비선형적으로 감소하였으나, 함수율 25% 이상에서는 응력파에 의해 구한 영계수의 변화가 거의 없었다.

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Resonant Frequency in Rectangular Microstrip Patch Antenna on Uniaxial Substrates with Airgap (공기 갭을 갖는 일축성 매질 위의 마이크로스트립 패치 안테나의 공진 주파수)

  • 윤중한;이상목;안규철;곽경섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.12A
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    • pp.1759-1765
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    • 2000
  • 공기 갭을 갖는 일축성 기판위에 마이크로 패치 안테나의 공진 주파수가 full-wave approach와 모멘트 계산법을 이용하여 연구되었다. 일축성 매질내의 구성관계식을 통하여 제안된 구조에서의 파수영역 다이애딕 그린 함수를 유도하였으며 이 결과로부터 전계 적분 방정식을 수식화하였다. 갤러킨 모멘트법을 사용하여 전계 적분 방정식을 이산화 하였으며 기저함수의 선택은 수치 해석적 수렴을 고려하여 패치 위의 실제 전류밀도와 가장 유사한 형태인 정현적 기저함수를 선택하였다. 전사모의 실험 결과의 타당성을 검증하기 위해서 기존의 결과와 비교하여 일치된 결과를 얻었다. 공기 갭의 두께와 패치 길이, 이방성 비의 변화에 따른 공진 주파수가 제시되고 분석되었다.

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