• Title/Summary/Keyword: Precise parts

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WIRELESS SENSOR NETWORK BASED BRIDGE MANAGEMENT SYSTEM FOR INFRASTRUCTURE ASSET MANAGEMENT

  • Jung-Yeol Kim;Myung-Jin Chae;Giu Lee;Jae-Woo Park;Moon-Young Cho
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1324-1327
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    • 2009
  • Social infrastructure is the basis of public welfare and should be recognized and managed as important assets. Bridge is one of the most important infrastructures to be managed systematically because the impact of the failure is critical. It is essential to monitor the performance of bridges in order to manage them as an asset. But current analytical methods such as predictive modeling and structural analysis are very complicated and difficult to use in practice. To apply these methods, structural and material condition data collection should be performed in each element of bridge. But it is difficult to collect these detailed data in large numbers and various kinds of bridges. Therefore, it is necessary to collect data of major measurement items and predict the life of bridges roughly with advanced information technologies. When certain measurement items reach predefined limits in the monitoring bridges, precise performance measurement will be done by detailed site measurement. This paper describes the selection of major measurement items that can represent the tendency of bridge life and introduces automated bridge data collection test-bed using wireless sensor network technology. The following will be major parts of this paper: 1) Examining the features of conventional bridge management system and data collection method 2) Mileage concept as a bridge life indicator and measuring method of the indicator 3) Test-bed of automated and real-time based bridge life indicator monitoring system using wireless sensor network

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Electromagnetic-thermal two-way coupling analysis and application on helium-cooled solid blanket

  • Kefan Zhang;Shuai Wang;Hongli Chen
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.927-938
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    • 2023
  • The blanket plays an important role in fusion reactor and stands extremely high thermal and electromagnetic loads during operation situation and plasma disruption event, brings the need for precise thermal and electromagnetic analysis. Since the thermal field and EM field interact with each other nonlinearly, we develop a method of electromagnetic-thermal two-way coupling by using finite element software COMSOL. The coupling analyses of blanket under steady state and MD event are implemented and the results are analyzed. For steady state, the influences of coupling effects are relatively small but still recommended to be considered for a high precision analysis. The influence of thermal field on EM field can't be ignored under MD events. The variation of force density could cause a significant change in stress in certain parts of blanket. The influence of Joule heat during MD event is negligible, yet the potential temperature rise caused by induced current after MD event still needs to be researched.

Uplift Rate Map and Distribution of Uplift Rate in the East Coast of the Korean Peninsula (동해안의 융기율도와 융기율 분포)

  • Lee, Gwang-Ryul;Park, Chung-Sun
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.1
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    • pp.47-60
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    • 2020
  • This study tried to produce an uplift rate map and reveal the spatial distribution of the rate with topographical characteristics and absolute ages on marine terrace in the East Coast of the Korean Peninsula. Based on a total of 57 ages at 26 sites from previous study and 13 ages at 13 sites from this study, the coast showed the rates ranging from 0.145 m/ka to 0.410m/ka with an average of 0.258 m/ka. The highest and lowest rates were found from the Jeongdongjin area in Gangneung and the Goraebul area in Yeongdeok, respectively. However, some areas in the coast showed large differences in the rate among the sites. In addition, areas with only 1 age were also found, indicative of low reliability. This study suggests that a more reliable and precise interpretation on the rate can be made with more ages identified, especially in Goseong to northern part of Gangneung, middle and southern parts of Samcheok and Yeongdeok, southern part of Pohang to northern part of Gyeongju, and Ulsan.

Influence of Surface Roughness on Friction and Wear Characteristics of SUS 321 for Hydraulic Cylinder Parts Application

  • Sung-Jun Lee;Yonghun Jang;Chang-Lae Kim
    • Tribology and Lubricants
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    • v.39 no.6
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    • pp.244-249
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    • 2023
  • This paper presents a comprehensive analysis of the impact of surface roughness on the friction and wear properties of SUS 321, an austenitic stainless steel variant produced using the laser powder bed fusion (LPBF) technique, which is a prevalent additive manufacturing method. After the LPBF fabrication, the specimens go a heat treatment process aimed at alleviating residual stress. Subsequently, they are polished extensively to achieve a refined and smooth surface. To deliberately introduce controlled variations in surface roughness, an etching process is employed. This multi-step method encompassed primary etching in a 3M hydrochloric acid solution, followed by secondary etching in a 35 wt% ferric chloride solution, with varying durations applied to different specimens. A comprehensive evaluation of the surface characteristics ensued, employing precise techniques such as surface roughness measurements and meticulous assessments of water droplet contact angles. Following the surface treatment procedures, a series of friction tests are performed to explore the tribological behavior of the etched specimens. This in-depth investigation reached its peak by revealing valuable insights. It clarified a strong correlation between intentionally altered surface roughness, achieved through etching processes, and the resulting tribological performance of LPBF-fabricated SUS 321 stainless steel. This significantly advances our grasp of material behavior in tribological applications.

Development of K-Maryblyt for Fire Blight Control in Apple and Pear Trees in Korea

  • Mun-Il Ahn;Hyeon-Ji Yang;Sung-Chul Yun
    • The Plant Pathology Journal
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    • v.40 no.3
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    • pp.290-298
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    • 2024
  • K-Maryblyt has been developed for the effective control of secondary fire blight infections on blossoms and the elimination of primary inoculum sources from cankers and newly emerged shoots early in the season for both apple and pear trees. This model facilitates the precise determination of the blossom infection timing and identification of primary inoculum sources, akin to Maryblyt, predicting flower infections and the appearance of symptoms on various plant parts, including cankers, blossoms, and shoots. Nevertheless, K-Maryblyt has undergone significant improvements: Integration of Phenology Models for both apple and pear trees, Adoption of observed or predicted hourly temperatures for Epiphytic Infection Potential (EIP) calculation, incorporation of adjusted equations resulting in reduced mean error with 10.08 degree-hours (DH) for apple and 9.28 DH for pear, introduction of a relative humidity variable for pear EIP calculation, and adaptation of modified degree-day calculation methods for expected symptoms. Since the transition to a model-based control policy in 2022, the system has disseminated 158,440 messages related to blossom control and symptom prediction to farmers and professional managers in its inaugural year. Furthermore, the system has been refined to include control messages that account for the mechanism of action of pesticides distributed to farmers in specific counties, considering flower opening conditions and weather suitability for spraying. Operating as a pivotal module within the Fire Blight Forecasting Information System (FBcastS), K-Maryblyt plays a crucial role in providing essential fire blight information to farmers, professional managers, and policymakers.

The Study on the Sweating Responses of Adult Female according to Garment types (의복형태에 따른 성인여성의 발한반응에 관한 연구)

  • Yeom Hee Gyong;Choi Jeong Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.16 no.4 s.44
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    • pp.405-416
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    • 1992
  • This study was performed to investigate correlation between total body weight loss and local sweat rate and to find out any possible method that can estimate total body weight loss judging from local sweat rate. Twelve adult females were kept at 44 $\pm1^{\circ}C$, 50 ${\pm}5\%$ R.H. (1) Physiological responses such as total body weight loss, local sweat rate, rectal temperature, skin temperature, blood pressure and pulse, (2) micro climate inside garment and (3) subjective sensation were examined. Two types of garment such as long-sleeves with long pants (Type I) and half·sleeves with short pants (Type II) were used to observe the effect of garment types on sweating response. Both clothing weight was equal (132$\pm$3 g/$m^{2}$). The results were as follows: 1. Regardless of the different types, total body weight loss was more interrelated with the sweat rate on forehead than any other parts of the body. Except the forehead, different parts of body with different types of garment influenced on body weight loss quite differently. 2. Total body weight loss was more interrelated with the weight gain of garment than the local sweat rate. 3. Under the environment of 44$\pm1^{\circ}C,\;50{\pm}5\%$R.H., body weight loss during 1 hour of subject clothed and silted was 275.2 g/hr and weight loss per body surface area was 178.9 g/$m^{2}/hr$ Garment types have no influences on total body weight loss. 4. Local sweat rate (mg/7.07 $cm^{2}/hr$) was 208.0,191.0, 133.0, 115.0,81 0, 75.1 and 66.3 on scruff, breast, forehead, forearm, thigh, upper arm, leg respectively No evidence has been found that garment types influenced on local sweat rate (p<0.1). 5. No interrelationships between rectal temperature and total body weight loss, local skin temperature and total body weight loss, and local skin temperature and local sweat rate were found. From this study, some possible method that we can estimate total body' weight loss judging from weight loss of garment. But considering the fact that clothing design factor, the physical characteristics of fabric and environmental factor such as humidity and wind velocity should be concerned in weight loss of garment, it should be studied further whether the total body weight loss can be estimated properly from the weight loss of garment. This experiment suggest that different parts of body with different types of garment can influence on body weight loss quite differently. Therefore, in order to get more precise results, more studies under the diversity of garment types should be done in the near future.

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A Study on Digital Documentation of Precise Monitoring for Microscale Displacements within the Tomb of King Muryeong and the Royal Tombs in Gongju, Korea (공주 무령왕릉과 왕릉원 내부 미세변위 정밀모니터링을 위한 디지털 기록화 연구)

  • Choi, Il Kyu;Yang, Hye Ri;Lee, Chan Hee
    • Journal of Conservation Science
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    • v.37 no.6
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    • pp.626-637
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    • 2021
  • The tomb complex of the royal family from the period of the Ungjin Baekje Kingdom (475 to 538 AD) in Gongju, Korea, contains the tomb of King Muryeong and other royal tombs. After the excavation of the tomb of King Muryeong in 1971, these tombs were opened up to the public, without the establishment of systems for their safety, conservation and management. The tombs have consequently experienced rapid environmental changes and suffered various damages. In this study, specific vulnerable parts inside the tombs were selected for deviation analysis using 3D scanning, and 3D image models were constructed on this basis. Progressive displacement was identified in tomb No. 5, and basic data for future investigations was acquired from tomb No. 6 and the tomb of King Muryeong. In the deviation analysis for the southern plastered wall of tomb No. 5, the damage was not found to exceed the ranges of ±18 mm and ±2 mm. However, the lintel stone was found to be sagging by 0.32 mm on average, and the distance between the walls to have increased by 0.36 mm on average. Direct water seepage occurring in tomb No. 5 is considered to be increasing the damage within the tomb, such as the dropping and sagging of the lintel. The 3D image models constructed in this study will play an important role as baseline data for future research, and can be used to discuss a secure conservation scheme for the tombs through cross-validation with precise measurement monitoring.

Changes in Body Surface Lines Caused By Lower Limb Movements in Designing Slacks (I) (슬랙스 설계를 위한 하지동작에 따른 체표선 변화 1)

  • Cho Sung-Hee
    • Korean Journal of Human Ecology
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    • v.7 no.3
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    • pp.15-33
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    • 2004
  • A precise understanding of the human form in static pose serves as the basis of designing clothing. When the human body is in motion, however, even an article of clothing designed to fit the human form in static pose can pull and change, thus restricting the body. In order to increase the fit of the clothing, which may be termed the second skin, its form and measurements therefore must be determined in correlation not only with the formal characteristics of the human body, in static pose but also with its functional characteristics in motion, as caused by the movements of the human body. In this study, the motion factor was selected as the primary basis for designing slacks with good fit in both static and moving states. By indentifying the areas in which lower limb movement cause significant changes in body surface lines, we suggest several application methods for designing slacks. Using unmarried female university students aged 18 - 24 as subjects, a total of 32 body surface categories (15 body surface lines and 17 body surface segment lines) were measured in one static and 9 movement poses. In particular, expansion and contraction levels and rates were measured and used in the analysis. The analysis first involved the calculation of the average measurement per body part in body surface line in static pose as well as of the average expansion and contraction levels and rates in 9 lower limb movements. Two-way MANOVA and multiple comparison analysis (Tukey) were conducted on movements and individual somatotypes regarding measurement per body part and expansion and contraction rates. Body parts whose measurements of body surface lines differed significantly in body surface line in static pose versus in movement were then identified. The results of this study are as follows. First, changes in body surface lines caused by lower limb movements were significant in all body surface lines of the lower trunk, both horizontal and vertical, with the exception of abdomen girth, midway thigh girth, ankle girth, hip length, and posterior knee girth. Second, significantly expanded 10 body surface lines in moving pose were detected and illustrated in table 4. These body parts should be studied in designing or pattern designing, especially for close-fitting pants, in using stretch fabric, and in sensory evaluation of good fit during movement.

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On the terminology for pagoda subsidiaries in the manuscripts excavated from Seokgatap pagoda (석가탑 출토 묵서지편의 석탑 부재 관련 용어 고찰)

  • Joo, Kyeongmi
    • (The)Study of the Eastern Classic
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    • no.32
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    • pp.391-424
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    • 2008
  • A Buddhist relic deposit was discovered from the three storied stone pagoda which was called as Seokgatap of Bulguksa temple in Gyeongju in 1966. In this relic deposit, several clumped papers written in ink which were found from the pagoda. These manuscripts are one of the most valuable materials for understanding Korean Buddhism and Buddhist Art History. In this paper, I examined several terms for pagoda subsidiaries found in these manuscripts, which have not been known to us up to recently. In addition, I compared these terms to the real pagodas or pagoda images in Korea. The manuscripts from Seokgatap pagdoa were composed of three different kinds of records; (1) "Record for the Repair of Mugujeonggwangtap Pagoda (無垢淨光塔重修記, 1024)"; (2)"Record for the Reconstruction of West Pagoda (西石塔重修形止記, 1038); (3)"Lists of Donors for the Reconstruction of the Pagoda in Bulguksa temple (佛國寺塔重修布施名公衆僧小名記, 1038). The terminology describing pagoda was appeared in the first and the second records. In the "Record for the Repair of Mugujeonggwangtap Pagoda", there are more than ten terms, which are presumed to be the words describing some upper decorative parts of a stone pagoda. However, in the "Record for the Reconstruction of West Pagoda", there are fifteen terms which would describe the body and base parts of the Seokgatap pagoda. These new terms for pagoda subsidiaries appeared in the manuscripts of Seokgatap Pagoda are very significant materials in understanding Korean Buddhist Art, because they show the practical terms which were used in the eleventh century Buddhism of Korea, but never known to the modern academic world. The manuscripts of Seokgatap Pagoda have not been deciphered perfectly yet, so they have to be examined with more precise as well as with wider view of Buddist and Art History.

Specification-based Program Slicing and Its Applications (명세 기반 프로그램 슬라이싱 기법과 응용)

  • Chung, In-Sang;Yoon, Gwang-Sik;Lee, Wan-Kwon;Kwon, Yong-Rae
    • Journal of KIISE:Software and Applications
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    • v.29 no.8
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    • pp.529-542
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    • 2002
  • More precise program slices could be obtained by considering the semantic relations between variables of interest, compared to the existing slicing techniques considering only the syntactic relations. In this paper, we present specification-based slicing that allows a better decomposition of the program by taking a specification as its slicing criterion. A specification-based slice consists of a subset of program statements which preserve the behavior and the correctness of the original Program with respect to a specification given by a pre-postcondition pair. Because specification-based slicing enables one to focus attention on only those program statements which realize the functional abstraction specified by the given specification, it can be widely used in many software engineering areas. Of its possible applications, we show how specification-based slicing can improve the Process for extracting reusable parts from existing programs and restructuring complex programs for better maintainability.