• Title/Summary/Keyword: structure functionality

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Development of Multi-channel Eddy Current System for Inspection of Press Rolls (압연롤 검사를 위한 다중 센서 와전류 탐상 검사 시스템 개발)

  • Lee, Jae-Ho;Park, Tae-Sung;Park, Ik-Keun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.3
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    • pp.306-312
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    • 2017
  • Press rolls are constantly exposed to physical and heat stresses on their surface and are prone to crack, bruise, and spall if the accumulated stress goes beyond the critical point. Such surface phenomenon can cause them to lose their functionality and eventually lead to a halted production line. Eddy current testing can be considered a useful method to investigate the surface of the roll. The method involves the application of a high intensity magnetic field onto the surface of the roll, and thereby finding any early stage of possible defects. When the method was applied for roll inspection, the cross section of the sensor was regulated as per the overall testing speed. A smaller cross sectional area implied a better resolution but a longer testing time. In this paper, a convenient method to increase both overall system resolution and inspection speed of eddy current roll inspection is suggested by using a devised array sensor structure.

A versatile software architecture for civil structure monitoring with wireless sensor networks

  • Flouri, Kallirroi;Saukh, Olga;Sauter, Robert;Jalsan, Khash Erdene;Bischoff, Reinhard;Meyer, Jonas;Feltrin, Glauco
    • Smart Structures and Systems
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    • v.10 no.3
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    • pp.209-228
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    • 2012
  • Structural health monitoring with wireless sensor networks has received much attention in recent years due to the ease of sensor installation and low deployment and maintenance costs. However, sensor network technology needs to solve numerous challenges in order to substitute conventional systems: large amounts of data, remote configuration of measurement parameters, on-site calibration of sensors and robust networking functionality for long-term deployments. We present a structural health monitoring network that addresses these challenges and is used in several deployments for monitoring of bridges and buildings. Our system supports a diverse set of sensors, a library of highly optimized processing algorithms and a lightweight solution to support a wide range of network runtime configurations. This allows flexible partitioning of the application between the sensor network and the backend software. We present an analysis of this partitioning and evaluate the performance of our system in three experimental network deployments on civil structures.

Analysis of sEMG Median frequency and Ultrasound Image Echodensity of Normal Skeletal Muscle (정상 골격근의 근전도 중앙주파수 및 초음파 영상 밀도 분석)

  • Jeong, Jin-Gyu;Kim, Yong-Nam;Hwang, Tae-Yeun;Lee, Jeong-Woo;Kim, Tae-Youl
    • The Journal of Korean Physical Therapy
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    • v.18 no.1
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    • pp.83-94
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    • 2006
  • Purpose: This study conducts quantitative evaluation or structural and functional characteristics or normal skeletal muscle with ultrasound image and surface electromyography, and is to provide basic materials for utilizing ultrasound image analysis in physical therapy diagnosis and assessment of skeletal muscle. Methods: Measurement of three stages was conducted with 88 normal adults between their twenties and seventies, correlations and differences using collected data according to age and gender were compared and correlations among measured items were analyzed and then the following conclusions were obtained. Results: Analysis of ultrasound image of normal skeletal muscle showed that density, median frequency had the closest relations with age. In addition, it was found that there were high correlations between density explaining structural characteristics of skeletal muscle and median frequency explaining functional characteristics. Conclusion: Analysis of ultrasound image makes complex evaluation of structure and function of skeletal muscle possible when it is connected with functional evaluation method using physical measurement surface electromyography as well as quantitative evaluation of structural changes of skeletal muscle and is effective in complementing physical therapy diagnosis centering around functionality evaluation.

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Effects of Addition of Green Tea Powder and Angelica Keiskei Powder on the Quality Characteristics of Yukwa (녹차가루 및 신선초가루 첨가가 유과의 품질 특성에 미치는 영향)

  • 김향숙;김순남
    • Korean journal of food and cookery science
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    • v.17 no.3
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    • pp.246-254
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    • 2001
  • Effects of added green tea powder and Angelica keiskei powder on the quality characteristics of Yukwa were examined for the purpose of improving functioanality and variety of Yukwa, and usage of green tea Powder and Angelica keiskei. Dietary fiber contents of green tea powder were 5.2% soluble dietary fiber, 22% insoluble dietary fiber, while Angelica keiskei contained 28.9% soluble dietary fiber, 29.6% insoluble dietary fiber. Expansion rate of yukwa was 3,675% for control and the rates were slightly decreased as the addition level increased. Although Yukwas added 6% green tea and angelica keiskei powder were harder than the others when determined by rheometer, sensory evaluation results showed that hardness and mouthfeel were soft without any significant difference among the control and experimental samples. And internal structure of 4 and 6% green tea powder and those added angelica keiskei at three levels were evaluated by sensory panel as moderately compact. Overall acceptability of yukwa added 2% green tea Powder was the best of all while yukwas added angelica keiskei at three levels were evaluated as good. The results of peroxide value and TBA value showed that green tea powder had stronger antioxidative property than angelica keiskei. In conclusion addition of green tea powder by 2% level and angelica keiskei powder up to 4% would give us beneficial effects in the aspects of functionality and storage life of yukwa without any detrimental effects on the quality characteristics of it.

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Application of Rasch Analysis to the Modified Oswestry Low Back Pain Disability Questionnaire for Work-Related Low Back Pain Patients (수정된 오스웨스트리 허리기능 장애 설문지의 라쉬분석: 산업장에서의 업무관련 요통환자를 대상으로)

  • Park, So-Yeon;Oh, Jae-Seop;Yi, Chung-Hwi
    • Physical Therapy Korea
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    • v.15 no.3
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    • pp.26-34
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    • 2008
  • The purposes of this study were to assess and modify the original classification categories of the modified Oswestry Low Back Pain Disability Questionnaire (ODQ) and to determine the unidimensionality of the modified ODQ applying Rasch Analysis. The data were obtained from 108 work-related low back pain patients by physical therapists. Construct validity of the scale using the Rasch model required the structure of the rating scale to be modified from 6 response levels to 4 response levels. Eight items from the modified ODQ fit the Rasch model. The items, "pain intensity" and "social life" showed misfit statistics. In general, the order of item difficulty of the remaining 8 items showed a logical item difficulty hierarchy with the "changing degree of pain" item being the most difficult and the "walk" item being the easiest. The results showed that further study is needed to expand the construct of ODQ including additional higher-level items related to work activities. This study may be useful for establishing a standard method to assess the functionality of low back pain patients.

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A Study on the Characteristics of ALC Material with Melamine Resin (멜라민 수지를 혼합한 ALC 소재의 특성에 관한 연구)

  • Seo, Sung-Kwan;Chu, Yong-Sik;Song, Hun;Lee, Jong-Kyu;Im, Du-Hyuk
    • Journal of the Korean Ceramic Society
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    • v.48 no.6
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    • pp.595-599
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    • 2011
  • ALC(Autoclaved Lightweight Concrete) is produced using quartz sand, lime and cement and water. And aluminum powder is used for blowing agent. ALC is manufactured by autoclave chamber under high-temperature and high-pressure. Generally, ALC is 1/4 levels lighter than concrete and mortar, because it has a lot of pores. So density of ALC is about 0.45~0.65 g/$cm^3$. But, ALC has a weakness, typically low strength, with its porous structure. So, it is necessary to excellent strength properties for extensive apply of ALC materials in high porosity. In this study, melamine resin was used to improve the strength characteristics of ALC materials. We performed compressive and bending strength measurements. Compressive strength of ALC with 2% melamine resin increased 26.88% than 'melamine-free' ALC. Also we performed functionality evaluation such as thermal conductivity, sound absorption, and flame-resistance.

A Study on Ergonomic Fashion Design - Focused on Body Conscious Active Sportswear - (에르고노믹 패션 디자인연구 - 바디컨셔스 액티브 스포츠웨어를 중심으로 -)

  • Kim, Hyunju;Na, Hyunshin
    • Fashion & Textile Research Journal
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    • v.16 no.3
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    • pp.434-445
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    • 2014
  • The meaning of this research is to make recognition for necessity of ergonomic fashion design research. And the purpose is to provide the guidelines for ergonomic fashion product development. For this, literature research and analysis of empirical illustration of product design indicating ergonomics characteristic are implemented. Among the body-conscious active sportswear, cycle wear, swim suit, and skin scuba wet suit were selected and analyzed. Then they were explained according to the ergonomics characteristics arranged previously. Lastly, the features of ergonomic fashion design were arranged by composition elements of the clothing such as pattern, sewing, material and detail. The characteristics of ergonomic design derived from literature and advanced researches are efficiency, usability, functionality and safety. Through research and analysis, the characteristics of ergonomic fashion design are as followings. In pattern, it is related to the 3D structure division pattern, the reduction pattern design, the closing & opening part design for easy detachment, the receipt and the changeable design. In sewing, it is related to the use of latest sewing techniques and the finish using silicon or rubber band. In material, it is related to the use of high performance fabrics and the proper arrangement of these. In detail, it is related to the convenient detail, the storage detail, the adjustable detail, and the body protection detail.

A 3D bioprinting system and plasma-surface modification to fabricate tissue engineering scaffolds (조직공학용 세포담체 제작을 위한 플라즈마-표면개질이 포함된 바이오프린팅 시스템)

  • Kim, Geun-Hyeong
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.3-23
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    • 2017
  • The achievement of tissue engineering can be highly depending on the capability to generate complicated, cell seeded three dimensional (3D) micro/nano-structures. So, various fabrication techniques that can be used to precisely design the architecture and topography of scaffolding materials will signify a key aspect of multi-functional tissue engineering. Previous methods for obtaining scaffolds based on top-down are often not satisfactory to produce complex micro/nano-structures due to the lack of control on scaffold architecture, porosity, and cellular interactions. However, a bioprinting method can be used to design sophisticated 3D tissue scaffolds that can be engineered to mimic the tissue architecture using computer aided approach. Also, in recent, the method has been modified and optimized to fabricate scaffolds using various natural biopolymers (collagen, alginate, and chitosan etc.). Variation of the topological structure and polymer concentration allowed tailoring the physical and biological properties of the scaffolds. In this presentation, the 3D bioprinting supplemented with a newly designed plasma treatment for attaining highly bioactive and functional scaffolds for tissue engineering applications will be introduced. Moreover, various in vivo and in vitro results will show that the fabricated scaffolds can carry out their structural and biological functionality.

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Analytical and Numerical Study on Mechanical Behavior of Unit Cell of Pyramidal Truss Core Structures (피라미드 트러스 코어 단위셀의 기계적 특성에 관한 해석적 및 수치적 연구)

  • Kim, Sang-Woo;Lee, Young-Seon;Kang, Beom-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.5
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    • pp.623-631
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    • 2011
  • Metallic sandwich panels based on a truss core structure have been developed for a wide range of potential applications with their lightweight and multi-functionality. Structural performance of sandwich panels can be predicted from the studies on mechanical behavior of a unit cell of truss core structures. Analytical investigations on the unit cell provide approximated guidelines for the design of overall core structures for a specific application in short time. In this study, the effects of geometrical parameters on mechanical behavior of a pyramidal shape of unit cell were investigated with analytical models. The unit cell with truss member angle of 45 degree was considered as reference model and other models were designed to have the same weight and projected area but different truss member angle. All truss members were assumed to be connected with pin joint in analytical models. Under the assumptions, the equivalent strength and stiffness of the unit cell under compressive and shear loads were predicted and compared. And finally, the optimum core member angle to have maximum mechanical property could be calculated and verified with FE analysis results.

Preparation of Eco-friendly and High Strength Paper for Viscose Rayon Yarn (친환경 고강도 인견사용 종이 제조)

  • Hwang, Sung-Jun;Kim, Hyoung-Jin;Bae, Paek-Hyun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.6
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    • pp.154-163
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    • 2015
  • Because of acute or chronic intoxication by carbon disulfide, viscose rayon industry is strictly subjected to environment regulatory approval. Recently, non-wood fibers are frequently considered as a raw materials for the manufacture of specialty paper for the higher physical strength and functionality. Among the non-wood fibers, hemp bast fiber is one of the most widely used materials in viscose rayon yarn industries. In this study, the handsheet for manufacturing the viscose rayon yarn was prepared with wood pulp fibers and hemp bast fibers. The proper mixing ratio of wood fibers and hemp bast fibers with dry-strength agent and nano-celluloses was analysed in terms of physical and mechanical strength of sheet for viscose rayon yarn. The papermaking conditions for high mechanical strength of sheet were obtained by mixing the SwBKP and HwBKP fibers with freeness level of 200 mL CSF. The dual polymer system by controlling the addition ratio of PVAm and anionic PAM was also important. The addition of nano-cellulose into wet-end furnishes increased the physical strength of sheet, and improved the paper structure for the production of viscose rayon yarn.