• 한국기계가공학회지
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• 제17권2호
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• pp.54-59
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• 2018

In this study, the durability due to the fork shape of excavator bucket is investigated. The analysis is carried out by modelling the fork shape used in general. As the analysis condition, the pin is constrained as fixed support at the bucket and the load of 12000N is applied at the fork. As the study result, the maximum equivalent stresses at models 1 and 2 are shown as 56.895MPa and 54.722MPa respectively. Model 1 is shown to have the most deformation of 5.6686 mm among four models. Model 3 has the least deformation among four models and the maximum deformation of model 3 is shown as 4.948mm. The fatigue analyses are also carried out with three models. Each model shows the same fatigue lives under the identical fatigue loads. The damage part at each model is shown at the bucket pork or the pin connected with bucket. As this study result, the data is thought to contribute to the safety design at excavator bucket.

• 한국정밀공학회지
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• 제16권10호
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• pp.203-208
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• 1999

By tilting the reference mirror of Twynman-Green interferometer having a reference mirror and a moving mirror, firinge pattern composed of bright and dark parallel lines can be obtained and the fringe pattern is shifted according to the displacement of the mowing mirror. Several studies are executed for displacement measurement by detecting the intensity of the fringe with photo-diodes having small detecting area. In this study, to improve the sensitivity and robustness, the intensity of fringe is detected by using a large-area quadratic photo-diode masked with a grating panel having four kinds of binary grating having phase-difference of 0, {\pi}$/4, {\pi}$/2, 3 {\pi}$/4. The phase of the fringe is calculated with a simple 4-buckets algorithm. A experimental result shows that standard deviation of 5.653 nm is obtained comparing with a capacitive type gap sensor having nearly 1 nm accuracy.

• 한국간호교육학회지
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• 제21권1호
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• pp.129-140
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• 2015

Purpose: The purpose of this study was to analyze the types of attitudes of nursing students in Korea toward bucket lists. Methods: The Q-methodology, which provides a method for analyzing the subjectivity of each item was used. From each of the 37 subjects, 34 selected Q-statements were classified into the shape of a normal distribution, using a 9-point scale. The collected data were analyzed using a QUANL PC program. Results: Four types of attitudes toward the bucket list of subjects were identified in Korean nursing students. Type I is a pursuit of money type, Type II is a pursuit of relationship type, Type III is a pursuit of self-centered type, and TypeIV is a pursuit of others-centered type. Conclusion: The results of this study indicate that different approaches toward educational programs for students in the human service area are recommended based on the four types of nursing students' attitudes toward the bucket list.

• 한국식품영양과학회지
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• 제32권5호
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• pp.695-699
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• 2003

본 연구는 기존의 콩나물 재배통이 가지는 재배 중 발생하는 재배통 중심부의 고온과 탄산가스 수준의 증가로 인한 부패현상과 생육저해 문제를 해결하기 위한 것이다. 이 문제를 해결하기 위해서 원리적으로는 콩나물 재배통 내의 공기와 재배실과의 공기치환이 보다 원활히 일어나도록 한 것으로, 콩나물 재배통을 재배통과 콩나물 받침그릇으로 구성하였는데 재배통의 바닥에는 직경 10 mm, 높이 2 mm인 배수구 겸 물 고임 턱 다섯 개를 두었고 재배통 벽에는 폭 0.5cm, 길이 10 cm의 홈을 두었다. 재배통 속에 넣어 사용하는 콩나물 받침그릇에는 바닥에 배수구가 592개 형성되고 그 바닥 중앙에 직경 2 mm인 구멍 36개가 형성된 공기 치환파이프를 부착하여 콩나물 받침 그릇으로 구성하였다. 이렇게 구성한 개량콩나물 재배통은 25$\pm$1$^{\circ}C$에서 재배한 결과 기존 재배통보다 재배기간 동안 재배통 내의 탄산가스 수준과 온도가 낮았고, 그 결과 부패율은 낮고 성장 정도는 높은 결과를 얻었다.

• 산업공학
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• 제11권3호
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• pp.1-13
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• 1998

This paper addresses a scheduling scheme for Flexible Flow Shop(FFS) in the case that a factory is a sub-plant of an electronic device manufacturing plant. Under this environment, job orders for the sub-plants in the production route are generated together with job processing time bucket when the customer places orders for final product. The processing time bucket for each job is a duration from possible release date to permissible due date. A sub-plant modeled FFS should schedule these jobs orders within time bucket. Viewing a Printed Circuit Board(PCB) assembly line as a FFS, the developed scheme schedules an incoming order along with the orders already placed on the scheduled. The scheme consists of the four steps, 1)assigning operation release date and due date to each work cells in the FFS, 2)job grouping, 3)dispatching and 4)machine allocation. Since the FFS scheduling problem is NP-complete, the logics used are heuristic. Using a real case, we tested the scheme and compared it with the John's algorithm and other dispatching rules.

• 동력기계공학회지
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• 제20권3호
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• pp.36-42
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• 2016

A cylinder control system of the conventional construction machine has been controlled by hydraulic spool valves. This system is low-cost but system efficiency is not high. Recently, to improve this, all valves are controlled electronically and independently. Bu and Yao suggested four way electronic hydraulic control valve system. It is called IMVT(Independent Metering Valve Technology). The purpose of the study is to find proper IMV pressure control method for excavator and to validate excavator's bucket regeneration energy effect by controlling the IMV system. In this paper, we mathematically describe the bucket system of excavator first. And then, based on these results, we design the control system which is divided into two operations(none regeneration or regeneration).The results of the experiment show the desirable performance and usefulness of the designed control system.

• 한국축산시설환경학회지
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• 제3권2호
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• pp.87-95
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• 1997

This study was peformed to compare work routine time and performance of milking systems by measuring motion and time in milking procedure. Data were collected from thirteen dairy farms among which milking was done by bucket in two farms, by pipelines in three, by tandem parlors in four including one remodeled side-opening, by herringborn parlors in three and by a parallel milking parlor. Recording time and motion for milking parlor. Recording time and motion for milking procedure was performed by stopwatch and notebook computer. Work routine elements were recorded and calculated into cows milked per-man-hour(CMPH). The results are as follows : Average milking time per cow(MTPC) in bucket and pipeline milking systems usually installed in cow stall were 442.7 and 395.8 seconds, respectively. And average CMPH of bucket and pipeline milking system were 144.5, 303.3, 272.5 and 380.3 seconds, respectively. And CMPH of tandem, herringbone, parallel and modified side-opening systems were 24.9, 11.9, 13.2 and 9.5 heads, respectively. CMPH was the highest in the tandem milking system and the lowest in the bucket milking facilities. CMPH, when milked in a parlor resulted in high value compared with bucket or pipeline milking systems installed in cow stable. They showed considerably low CMPH compared with the results of other countries. The reason why so low CMPH could be derived from type and mechanization of facilities and equipment, operator's ability, number of operator, idle time and milking procedure.

• 한국정밀공학회지
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• 제25권3호
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• pp.93-100
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• 2008

Laser interferometry is widely used as a measuring system in many fields because of its high resolution and ability to measure a broad area in real-time all at once. In conventional LASER interferometry, for example Out-of-plane ESPI(Electronic Speckle Pattern Interferometry), In plane ESPI, Shearography and Holography, it uses PZT or other components as a phase shift instrumentation to extract 3D deformation data, vibration mode and others. However, in most cases PZT has some disadvantages, which include nonlinear errors and limited time of use. In the present study, a new type of LASER interferometry using a laser diode is proposed. Using LASER Diode Sinusoidal Phase Modulating (LD-SPM) interferometry, the phase modulation can be directly modulated by controlling the LASER Diode injection current thereby eliminating the need for PZT and its components. This makes the interferometry more compact. This paper reports on a new approach to the LD Modulating interferometry that involves four-buckets phase shift method. This study proposes a four-bucket phase mapping algorithm, which was developed to have a guaranteed application, to stabilize the system in the field and to be a user-friendly GUI. In this paper, the theory for LD wavelength modulation and sinusoidal phase modulation of LD modulating interferometry is shown. Four-bucket phase mapping algorithm is then introduced.

• 한국식품영양과학회지
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• 제28권4호
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• pp.886-889
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• 1999

To develope the soybean sprouting equipment(a type of cabinet) for medium amount(one bucket; 10~13kg) production of soybean sprouts, the watering system was made of four siphons and four the bottle necked water tank. Diameter of four siphons used for development of the watering system were 8, 13, 17 and 21mm, respectively and their water exhausting volumes were 40, 92, 154, 524ml/sec, respectively. The watering system can be automatically watered 524ml/sec without electric supply. The soybean sprouting equipment is consisted of four the bottle necked water tanks with the four siphons and six sprouting buckets with net shaped bottom for water draining. The soybean sprouting equipment with the watering system may be produced more than one box a day in the condition of 6~7 watering times a day at 25~30oC.

• 한국정밀공학회지
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• 제26권5호
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• pp.72-78
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• 2009

We propose the separation algorithm to simultaneously measure two-dimensional refractive index distribution and thickness profile of transparent samples using three wavelengths. The optical system was based on the Mach-zehnder interferometer with LD (Laser Diode)-based multi-wavelength sources. A LCR (Liquid Crystal Retarder) was used to obtain interference images at four phase states and then the optical phase of the object is calculated by four-bucket algorithm. Experimental results with a glass rod are provided at the different wavelengths of 635nm, 660nm and 675nm. The refractive indices of the sample are distributed with accuracy of less than 0.0005 and the thickness profile of sample was cylindrical type. This result demonstrates that it is possible to separate refractive index distribution and thickness profile of samples in two dimensions using the proposed algorithm.