• Title/Summary/Keyword: Bench

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Design of the Blade-Type Optical Bench for Earth Observation Satellite (지구관측위성의 블레이드형 광학탑재체 지지구조물 설계)

  • Kim, Kyung-Won;Kim, Jin-Hee;Rhee, Ju-Hun;Jin, Ik-Min;Kim, Jong-Wo;Park, Jong-Sung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.11
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    • pp.88-94
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    • 2005
  • This paper is a study on the blade-type optical bench satisfying stiffness and thermal pointing error requirements for earth observation satellite. According to shape requirements, optical bench is designed. Because it does not satisfy the stiffness requirement, the stiffener is added on the outer/inner area of optical bench. But it does not meet the thermal pointing error requirement. So symmetrical structure is suggested with platform support structure attached on the upper/lower part of platform. Although it has better value than previous case, it still does not meet the thermal pointing error requirement. Based on the results of prior cases, optical bench finally designed, which satisfied both the stiffness and thermal pointing error requirements. Next conclusions follow from this design. It is efficient to increase thickness of platform facesheet, add stiffener and increase blade number to raise stiffness. It is effective to connect component consisting of same material and design optical bench having symmetrical structure to lower thermal pointing error.

A Study on Bench Design Applied the Concept of Space (공간개념을 적용한 벤치디자인 개발 연구)

  • Jung, Myung-Taek;Yoon, Yeoh-Hang
    • Journal of the Korea Furniture Society
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    • v.23 no.1
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    • pp.75-83
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    • 2012
  • Space dominates all the art activities human do and plays a role of providing aesthetic emotion. Architecture, sculpture, painting, and furniture, etc. these two and three dimensional works are represented in space and interpreted the role of its form, structure and function. Each area is different, but space has been studied in philosophy, physics, geometry, and mathematical studies, etc. and has been consistently interpreted and represented relating to a variety of human creative activity. Furniture is also three dimensional art being dependent on space. In the United States in 2004, I made the living room bench by applying the spatial concept at Rochester Institute of Technology. Two years later, this design was adopted by wendell Castle Collection, an American furniture company, then prototype were made and tested three times during a year, and then since 2007 as indoor benches it has been manufactured in the United States. The study's purpose is to order the process of its development based on the experience of bench production applied the spatial concept, and by analyzing the properties of spatial concept, I am planning to propose a new concept on interaction with the space and furniture for next.

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Cost Comparisou of Conveyance Systems for Irrigation Districts (관개용수로의 비용분석에 관한 연구)

  • 최창훈;고재군;박승우;이신호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.27 no.4
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    • pp.31-41
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    • 1985
  • This paper compares the estimated total construction and maintenance costs for irrigation canals in six irrigation districts near Pyongtaek. Three conventional canal types were considered: concrete bench flumes, concrete-lined canals, and earth canals. The total expenses for each type were grouped to four catagories: the net construction, land acquisition, maintenance, and other expenses. The construction costs included the assumed costs for conveyance losses from each type of canals. The results from this study support earlier studies that the bench flumes are economically feasible. Initially cheaper conveyance systems like concrete-lined and earth canals demand 'higher maintenance costs and thus, their total expenses are summed to exceed those for the bench flumes within a few years following the construction. Banch flumes are economically justifiable for the main canals of the studying districts. Sensitivity analyses were executed to evaluate the relative importance of each expense to the total cost. The analyses show that total expenses very significantly with the change of the following costs: cost for conveyance losses, net construction, maintenance, and land acquisition, in that order However, other expenses contribute little if not at all to the total. The results indicate that bench flumes should be adopted as main canal structures for most irrigation districts in the Republic.

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Analysis of In-situ Rock Conditions for Fragmentation Prediction in Bench Blasting (벤치발파에서 파쇄도 예측을 위한 암반조건 분석)

  • 최용근;이정인;이정상;김장순
    • Tunnel and Underground Space
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    • v.14 no.5
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    • pp.353-362
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    • 2004
  • Prediction of fragmentation in bench blasting is one of the most important factors to establish the production plan. It is widely accepted that fragmentation could be accurately predicted using the Kuz-Ram model in bench blasting. Nevertheless, the model has an ambiguous or subjective aspect in evaluating the model parameters such as joint condition, rock strength, density, burden, explosive strength and spacing. This study proposes a new method to evaluate the parameters of Kuz-Ram model, and the predicted mean fragment sizes using the proposed method are examined by comparing the measured sizes in the field. The results show that the predictions using Kuz-Ram model with the proposed method coincide with field measurements, but Kuz-Ram model does not reflect the in-situ rock condition and hence needs to be improved.

Bench-scale Test of Sulfuric Acid Decomposition Process in SI Thermochemical Cycle at Ambient Pressure (SI 열화학싸이클 황산분해공정의 Bench-scale 상압 실험)

  • Jeon, Dong-Keun;Lee, Ki-Yong;Kim, Hong-Gon;Kim, Chang-Soo
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.2
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    • pp.139-151
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    • 2011
  • The sulfur-iodine (SI) thermochemical water splitting cycle is one of promising hydrogen production methods from water using high-temperature heat generated from a high temperature gas-cooled nuclear reactor (HTGR). The SI cycle consists of three main units, such as Bunsen reaction, HI decomposition, and $H_2SO_4$ decomposition. The feasibility of continuous operation of a series of subunits for $H_2SO_4$ decomposition was investigated with a bench-scale facility working at ambient pressure. It showed stable and reproducible $H_2SO_4$ decomposition by steadily producing $SO_2$ and $O_2$ corresponding to a capacity of 1 mol/h $H_2$ for 24 hrs.

A Study on the Improvement Plan of Bench Design at a Subway Platform (지하철 승강장 벤치 디자인 유형의 개선방안에 관한 연구)

  • Yang, Hae Won;Kim, Joon Ji;Lee, Joo Hyun;Lee, Hyun Soo
    • KIEAE Journal
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    • v.8 no.2
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    • pp.71-78
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    • 2008
  • Subway is a major transportation in the city that is allied to the daily life of people. As a public space, subway station must satisfy the citizens with convenience, safety and esthetic factors. The bench which is one of the major street furniture on the subway platform has a lot of physical contact. Therefore the design of benches must be considered in the aspects of not only aesthetic design but also ergonomic design. The goal of this study is to find out the current conditions and problems of benches and at the same time suggest how to arrange, design, and manage them at the proper manners at subway platform. The result of the study is as follows. First, the problems of design are that the benches at a same platform have various design, the saturation of color is too high, and the design is unfashionable. The second, at the management part there is no such a total management system and specialist for the street furniture section and lack of rational management regulations. The third, results of a new survey suggest that citizens think negatively about present bench's conditions such as design and administration.

Study on Evaluation Method of Flow Characteristics in Steady Flow Bench(2) - Comparison of ISM and PIV Measurement (정상유동 장치에서 유동 특성 평가 방법에 대한 연구(2) - ISM와 PIV 측정의 비교)

  • Park, Chanjun;Ohm, Inyong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.1
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    • pp.139-147
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    • 2015
  • This paper is the second investigation on the evaluation methods of flow characteristics in a steady flow bench. In the previous work, several assumptions used in the steady flow bench were examined and it was concluded that the assumption of the solid rotation might cause serious problems. In this study, intake valve angle is selected as a main parameter for the assessment because the main flow direction to cylinder governed by this angle has the strongest influence on the in-cylinder flow pattern. For this purpose, four heads, which have the different angle, are prepared and the flow characteristics are estimated both by the conventional impulse swirl meter and a particle image velocimetry at 1.75 times bore position apart from the cylinder head, which is widely used plane in the steady flow measurement. The results show that both of the eccentricity and the velocity profile distort the flow characteristics when using the ISM at 1.75 plane, however, the effects of two factors act in the opposite direction. In addition, the profile's influence is much greater than that of the eccentricity.

Effect of Scapulothoracic Joint Movement and Resistance Training Intensity on Shoulder Complex Muscle Activation during Bench Press Exercise (벤치 프레스 운동 시 하중에 따른 어깨가슴관절의 움직임이 어깨복합체 근 활성도에 미치는 영향)

  • Kim, Yoon-Hwan;Lee, Ki-Kwang;Lee, Man-Ki
    • Korean Journal of Applied Biomechanics
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    • v.23 no.2
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    • pp.141-148
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    • 2013
  • The purpose of this study was to investigate the scapulothoracic joint movement between different weight bearing contributing to effective bench press exercise. Ten male subjects participated in this study. All subjects were tested on the flat bench press machine which modified weight (50% and 70% of 1RM) and subjects were performed two different conditions(none protraction condition and protraction condition). Weight bar height and vertical velocity, EMG activation was measured using 3D motion capture system and wireless EMG analysis system. As the results, none protraction condition showed that it is more concentrate better pectoralis major muscle activation than protraction condition and middle pectoralis major, anterior deltoid and triceps brachii was significant higher integrated EMG in 70% of 1RM condition. In conclusion, limited scapulothoracic joint movement was more effective activated pectoralis major muscle all the weight through, while we could not find that it was not affected integrated EMG on eight muslces related to shoulder complex between scapulothracic joint movement conditions.

Changes in Total Work, Total Work Ratio, Heart Rate, and Blood Lactate during 75% 1-RM Bench Press Exercise

  • Kim, Ki Hong;Kim, Byung Kwan
    • Medical Lasers
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    • v.10 no.3
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    • pp.153-160
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    • 2021
  • Background and Objectives This study was conducted to investigate the change of total work and total work ratio for each set, peak heart rate during exercise, and blood lactate for each set during the 5-set bench press exercise at 75% one repetition maximum test (1-RM). Materials and Methods Seven men in their 20s with more than 6 months of experience doing resistance exercises were selected as subjects, and their 1-RM bench press was measured two weeks before the experiment and 75% 1-RM was measured one week before the experiment. In this study, total work was measured for each set, and heart rate was measured during rest and set-by-set exercise. Blood lactate was measured during rest time after each set. The raw data were analyzed by repeated one-way ANOVA. Results Total work and total work ratio decreased from 1 set to 4 sets (p < .05), p < .001), heart rate increased from stable at the start of exercise (p < .001) and decreased between 3 sets and 4 sets (p < .05). Blood lactate increased continuously up to 2 sets (p < .001, p < .01). Conclusion In conclusion, total work and heart rate decreased with muscle fatigue during exercise, and blood lactate continuously increased. The results of this study are expected to be useful references for constructing resistance exercise programs in the future.

A Study on the Site Calibration of Network RTK Surveying (네트워크 RTK 측량의 사이트 캘리브레이션 방안에 관한 연구)

  • Choi, Han Jun;Lee, Byoungkil;Yeon, Sang Ho
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.1
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    • pp.99-107
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    • 2013
  • With the expansion of the development and use of surveying equipment recently, by the establishment of infrastructure for network RTK surveying of the NGII, network RTK surveying has been widely used in surveying industry. Currently, in public surveying regulations, site calibration with minimum 5 evenly spaced bench marks is needed for using network RTK surveying results as leveling. But the range between and the number of bench marks for site calibration can be varied according to the geoid undulation. In this study, in order to verify this, Incheon area having regular geoid undulation and Taebaek area having irregular geoid undulation are selected as study area and network RTK surveying have been done. Then the accuracy of site calibration by range between and the number of bench marks have been compared. As a result of this study, in order to meet a tolerance of vertical precision (0.1m) that has been set in public surveying regulations, there is a necessity for improving the regulations so that the range and number of bench marks, to be used for site calibration of network RTK surveying, can be applied complementarily.