• 제목/요약/키워드: Sectional measurement

검색결과 406건 처리시간 0.027초

3D 프린팅 기술을 적용한 스플린트의 제작 용이성 향상을 위한 아래팔 기하 정보 비교에 관한 연구 (A Study for Comparison of Geometric Characteristics on Forearms for Improvement of Convinience in Splint Manufacturing with 3D Printing Technology)

  • 장지홍
    • 한국정보전자통신기술학회논문지
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    • 제12권5호
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    • pp.475-481
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    • 2019
  • 스플린트는 마비, 구축 등이 나타난 환측에 적용하는 대표적인 보조기로서 전통적으로 숙련된 전문가의 수작업을 통해 제작된다. 제작과정은 열가소성 소재를 가열한 후 부드러워진 소재를 환측 부위에 접촉하며 해당 부위의 표면에 피팅시키는 과정을 반복하여 이루어진다. 이러한 전통적 방식은 저온화상의 위험, 제작자의 숙련도에 따른 완성도의 차이 등 여러 문제점을 가지고 있다. 이러한 단점을 보완하기 위하여 3D 프린팅 기술을 이용한 다양한 접근이 시도되고 있으나 3D 스캐너를 이용하는 경우 고비용의 문제, 수작업 측정의 경우 정확도의 문제 등의 단점을 나타내고 있다. 본 연구는 인체의 좌우 대칭성에 착안하여 건측 아래팔의 기하 특징을 이용하여 환측 스플린트를 3D 프린팅 기술로 제작하는 가능성에 관한 사전 연구이다. 디지털 사진과 사진측량기법을 이용하여 건강한 성인 남성으로부터 양측 아래팔의 3차원 가상 모델을 생성하고, 매 20mm 위치마다 둘레 길이 및 단면적을 측정하였다. 동일한 피험자네서 우세측과 비우세측 사이의 둘레 길이 및 단면적은 허용할 만한 수준의 차이를 나타냈으며, 우세측과 비우세측 사이에서 동일한 변수들 간에 높은 수준의 양의 상관관계를 나타냈다. 이러한 결과로부터 건측 아래팔의 기하 특징을 이용하여 3D 프린팅 기술의 적용을 통해 환측 스플린트 제작 가능성을 확인하였다.

Application of Gamma Ray Densitometry in Powder Metallurgy

  • Schileper, Georg
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2002년도 제3회 최신 분말제품 응용기술 Workshop
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    • pp.25-37
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    • 2002
  • The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

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부산지역 일부 노인들의 신체조성, 신체활동수준, 기초대사량 및 에너지소비량실태에 관한 연구 (A Study on the Body Composition, Physical Activity Level, Basal Metabolic Rate, and Daily Energy Expenditure of Elderly in Busan)

  • 임화재
    • 대한지역사회영양학회지
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    • 제21권2호
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    • pp.178-189
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    • 2016
  • Objectives: The objectives of the study were to assess body composition, physical activity level (PAL), basal metabolic rate (BMR), and daily energy expenditure (DEE) and to examine associations between PAL and body composition, BMR, and DEE of elderly in Busan. Methods: A cross-sectional study was conducted among 226 elderly aged 65-93 years. Body composition was measured by Inbody 720. PAL was calculated by daily activity diary. BMR was calculated by Harris-Benedict (H-B) formula, Dietary Reference Intakes (DRI) formula, and Inbody 720 measurement. DEE was calculated by H-B formula, DRI formula, Inbody 720 measurement, and estimated energy requirements (EER) formula. Results: The mean fat free mass (FFM) in elderly men was significantly higher than that in elderly women (p<0.001). The mean percent body fat and fat mass (FM) in elderly women were significantly greater than those in elderly men (p<0.001, p<0.001). The mean PAL in elderly men (1.59) was significantly higher than that in elderly women (1.53) (p<0.001). The mean DEEs calculated by 3 methods except for H-B formula in elderly men were higher than EER for elderly men (2000kcal). The mean DEEs calculated by 4 different methods in elderly women were higher than EER for elderly women (1600kcal). Age showed significantly negative correlations with height (p<0.001, p<0.001), FFM (p<0.001, p<0.001), BMRs calculated by H-B formula (p<0.001, p<0.001), DRI formula (p<0.001, p<0.001) and Inbody 720 measurement (p<0.05 p<0.01) and DEEs calculated by H-B formula (p<0.001, p<0.001), DRI formula (p<0.001, p<0.001), Inbody 720 measurement (p<0.05, p<0.05), and EER formula (p<0.001, p<0.001) in elderly men and elderly women. PAL showed significantly positive correlations with FFM (p<0.05), BMR by Inbody 720 measurement (p<0.05) in elderly men and negative correlations with FM (p<0.05) in elderly women. Conclusions: Based on the results, PAL was associated with greater FFM in elderly men and lesser FM in elderly women. Therefore, nutritional education to increase physical activity for health promotion in late life is needed in the elderly.

흥부 전산화단층촬영을 이용한 한국성인의 기관내경과 단면적의 측정 (CT Measurement of Diameter and Dimension of the Trachea in Normal Korean Adults)

  • 한재열;김광호;이건;김형진;조순구;선경
    • Journal of Chest Surgery
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    • 제34권7호
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    • pp.534-538
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    • 2001
  • 배경: 기관의 크기와 기관주위의 정상형태에 대한 지식은 임상에서 기도나 호흡관리, 그리고 기관재건술을 시행하는데 중요한 정보가 된다. 흉부 단순촬영은 기관의 직경을 재는 간단한 방법이지만 그 상이 확대되는 경향과 측면촬영에서 어깨와 상이 겹쳐서 나타나는 단점이 있다. 이에 저자들은 한국인 정상 성인의 기관의 정상치를 알기 위해 흥부 전산화 단층촬영을 이용하여 기관의 내경과 단면적을 측정하였다. 대상 및 방법: 남자 43명과 여자34명을 대상으로 하여 각각 나이에 따라 20~39세는 제 1군, 40~59세는 제2군, 60세 이상은 제 3군으로 구분하였다. 흉부 유입구와(Level 1) 대동맥궁에서(Level 2) 흉부 전산화 단층촬영을 이용하여 각각 전후경과 횡경을 재고 그 단면적을 구하였다. 결과: level 1에서 한국인 성인 남자의 기관의 전후경은 15.95$\pm$2.99 m, 횡경은 17.72$\pm$2.13 m이었고, 여자의 경우 전후경은 15.56$\pm$2.12 m, 횡경은 14.18$\pm$2.07mm로 남녀간에 유의한 차이가 있었다(p 0.05). Level 2에서 남자의 전후경은 19.77$\pm$2.57 m, 횡경은 18.02$\pm$2.19 mm이었고 여자의 전후경은 15.35$\pm$1.82 m, 횡경은 15.00$\pm$1.60 mm로 남녀간에 유의한 차이가 있었다 (p 0.05). 기관단면적은 남자가 각 Level에서 279.14$\pm$61.37 $\textrm{mm}^2$(Level 1), 281.93$\pm$63.97 $\textrm{mm}^2$(level 2)였고, 여자가 173.29$\pm$35.81 $\textrm{mm}^2$(Level 1), 181.88$\pm$34.74 $\textrm{mm}^2$(Level 2)로 두 위치에서 단면적은 남녀간에 유의한 차이가 있었다(p 0.05). 기관의 각각의 위치에서 내경과 단면적은 연령군에 따라 고연령층에서 증가하는 추세를 나타내었으나 통계적인 의미는 없었다. 결론: 한국 정상 성인의 기관내경과 단면적의 크기는 성별에 따라 통계적으로 유의한 차이가 있었으나 연령에 따른 차이는 없었고, 전산화 단층촬영은 기관의 내경과 단면적의 크기를 얻는데 비교적 정확하고 안전한 방법이라 생각된다.

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3차원 형상계측에 의한 니트 플레어스커트의 입체형상에 관한 연구 (A Study on the Solid Shapes of Knit Flare Skirts Using 3-Dimensional Image Analysis)

  • 기희숙
    • 한국의상디자인학회지
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    • 제13권2호
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    • pp.103-119
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    • 2011
  • This study set out to analyze the solid shapes of knit flared skirts, which are best represented in a 3-dimensional shape for all knit skirts, according to the seamed and seamless production method and to estimate the silhouettes of knit flared skirts based on the results. It also aimed to help with the introduction and spread of seamless weaving by revising and supplementing potential problems and provide findings that would be put to active use as basic data, thus contributing to the development of original knitwear and offering fundamental materials for the development of the knitting industry. A number of experimental knit flared skirts were made according to skirt angle ($90^{\circ}$ and $180^{\circ}$), gauge (7G, 12G, and 15G), and grain (bias, wale, and radial), including 12 kinds of seamed knit flared skirts and 6 kinds of seamless knit flared skirts. Using a three-dimensional shape measurement system, the investigator measured the cross-sectional shapes of their hemlines. The SPSS 12 Version program was used for statistical processing, and descriptive statistics such as mean and standard deviation were used to compare the seamed and seamless knit flared skirts in the measurements (measurement items) of their solid shapes according to the width, gauges, and grain directions. The central grain direction of seamless knit flared skirts was in a radial form and even hemlines, thus presenting a beautiful appearance and solid shape. The 3-dimensional shapes show that seamless knit flared skirts are superior to seamed ones. The research findings are expected to open a door for Korea's knitting industry to quickly respond to small quantity batch production and additional orders.

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입자 균등성 확보를 위한 시험 챔버의 유동 시뮬레이션 및 이를 이용한 기상 부유균 저감 특성의 실험적 연구 (Flow Simulation of Chamber System to Obtain Particle Uniformity and Study on Bio-aerosol Reduction Test)

  • 박대훈;현준호;황정호
    • 한국입자에어로졸학회지
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    • 제10권2호
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    • pp.83-91
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    • 2014
  • Since airborne bacteria have been known to aggravate indoor air quality, studies on reducing bacteria particles increase recently. In this study, a chamber(0.8m x 0.8m x 1.56m) system was built in order to simulate real conditions for reducing airborne bacteria, and evaluated by a simple aerosol reduction test. A method utilizing CFD(Computational Fluid Dynamics) simulation was used to detect the horizontal cross-sectional area which represents particle distribution in the chamber. Then an air-cleaner with HEPA filter and Carbon Fiber Ionizer was located on that area for aerosol reduction test. The CFD result found the area was located at 0.2m height from the bottom of the chamber, and the test showed aerosol reduction efficiencies using measurements of number concentration and CFU(colony forming unit) per each case. At the measurement of number concentration, the reduction efficiency of air-cleaner with filter and ionizer(Case 3) was about 90% after 4 minutes from the stop of the bacteria injection, and that with only filter(Case 2) was about 90% after 8 minutes from the beginning. Lastly, that without filter and ionizer(Case 1) was about 30% after 10 minutes. At the measurement of CFU, it shows similar results but it is related to viability of bio-aerosol.

저층 조적채움벽 철근콘크리트 골조의 내진보강 전후 동특성 변화 (Dynamic Properties of a Lowrise Masonry-infilled RC Frame Building Before and After Seismic Retrofit)

  • 유은종;김민재;김승남;김지영;최기선
    • 한국전산구조공학회논문집
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    • 제28권3호
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    • pp.293-300
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    • 2015
  • 본 연구에서는 저층 조적채움벽 철근콘크리트 골조 구조물의 내진보강 전과 후에 대하여 강제 진동 실험과 상시 진동 계측을 수행하였으며 시스템 식별과정을 통하여 구조물의 동특성을 구하고 해당 구조물과 유사한 동특성을 보이는 해석 모델을 만들었다. 시스템 식별 결과 댐퍼가 설치된 x방향의 감쇠비가 증가되었으며, 해석 모델과 비교한 결과 추가 설치된 부재들(전단벽과 댐퍼)의 유효 강성은 부재의 총단면 강성의 50%만이 발현되어 해당 부재들이 기존의 구조물이나 부재와 완전히 일체화되지는 않음을 알 수 있었다. 또한, 추가 설치된 기초의 y방향 구속조건을 핀으로 하여야 동특성을 일치시킬 수 있었는데, 이는 새로운 기초가 설치되며 해당 지질의 특성이 변화되었기 때문으로 보인다.

와류 현상을 이용하는 호흡기류센서 (Respiratory air Flow Transducer Based on air Turbulence)

  • 김경아;이인광;박준오;이수옥;신은영;김윤기;김경천;차은종
    • 대한의용생체공학회:의공학회지
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    • 제30권5호
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    • pp.393-400
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    • 2009
  • The present study developed a new technique with no physical object on the flow stream but enabling the air flow measurement and easily incorporated with the devices for cardiopulmonary resuscitation(CPR) procedure. A turbulence chamber was formed in the middle of the respiratory tube by locally enlarging the cross-sectional area where the flow related turbulence was generated inducing energy loss which was in turn converted into pressure difference. The turbulence chamber was simply an empty enlarged air space, thus no physical object existed on the flow stream, but still the flow rate could be evaluated. Computer simulation demonstrated stable turbulence formation big enough to measure. Experiment was followed on the proto-type transducer, the results of which were within ${\pm}5%$ error compared to the simulation data. Both inspiratory and expiratory flows were obtained with symmetric measurement characteristics. Quadratic curve fitting provided excellent calibration formula with a correlation coefficient>0.999(P<0.0001) and the mean relative error<1%. The present results can be usefully applied to accurately monitor the air flow rate during CPR.

A Comparative Study of Optimal Stretch Intensity For Flexibility of Hamstrings; Hand Held Dynamometer and Verbal Rating Scale

  • Choi, Bong-sam
    • 한국전문물리치료학회지
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    • 제24권4호
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    • pp.38-45
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    • 2017
  • Background: To improve muscle flexibility, static stretch is the most common type and is considered safe and effective for improving overall flexibility of muscles. During the stretch, the intensity is more likely to be determined by the degree of an athlete's pain and practitioner's skills rather than quantitative measures of stretch. It is necessary to determine the optimal intensity for the stretch. Objects: The purpose of this study is to explore the relationship between hand held dynamometer (HHD) and verbal rating scale (VRS) in comparison of the effects of continuance time on active (walking) and inactive (sitting) movement after static stretch. Methods: A cross-sectional study was conducted with a sample (n=62) recruited from a university. Participants were randomly assigned to 2 different groups (n=31 for each group) based on participants' positions either remaining in sitting or freely walking around for a series of re-assessments. Data was collected at pre-warm up, pre-stretch, post-stretch, and additional assessments at the time of 3, 6, 9, 12, 15, 20 and 30 minutes after the stretch. Results: Relationship between VRS and HHD scores represents very weak correlation (Spearman's p=-.16, p>.05). Pearson's correlation analysis was conducted following the logarithmic transformation of the two scores. Pearson's correlation after the transformation still showed a very low relationship and a poor linear relationship between the two scores (Pearson's r=-.18, p>.05). Conclusion: The optimal intensity for stretch cannot be solely determined by the subjective pain perception. The objective measurement such as HHD could be used in conjunction with the pain perception.

곡관의 하류에 설치된 전자기유량계의 유량신호 특성에 관한 실험적 연구(난류 유동) (An Experimental Study on Installation Effects of Pipe Elbow on the Electromagnetic Flowmeter Characteristics (Turbulent Flow))

  • 임기원
    • 대한기계학회논문집B
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    • 제26권11호
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    • pp.1613-1621
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    • 2002
  • An electromagnetic flowmeter(EMF) essentially averages the velocity distribution over the pipe cross- sectional area, and the measured value is dependent on the velocity profiles. In this study, installation effects of 90$^{\circ}$long elbow(KS B 1522, ISO 3419) on the EMF characteristics was investigated. A commercial EMF was adopted and the distribution of magnetic field in the electrodes cross section was measured. In the experiment, the national flow standard system, of which measurement uncertainty was evaluated in accordance with ISO 17025 recommendation, was used fur characterization of EMF. The leading line has 150D long straight pipe to established a fully developed flow before entering into the elbow and the elbow was installed downstream of it. then the flowmeter was tested within 50 D from the elbow. The installation effects of the flowmeter were investigated by varying the mean velocity(Reynolds No.)in pipe section, the locations and the direction of electrodes plane.($\phi$) From the experimental results, we find the optimal conditions to get most accurate measurements. Generally, the deviations from the calibration value were less than 0.5 % in farther than 10D distance from the elbow and the direction of electrode plane. $\phi$ = 90$^{\circ}$yielded the smallest measurement deviation. These characteristics were shown consistently in turbulent region regardless of the mean Reynolds number.