• Title/Summary/Keyword: LSD

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A Study of Limit State Design Method in Soil Slope (토사면의 한계상태 설계법에 관한 연구)

  • Joung, Gi-Hun;Kim, Jong-Min;Jang, Bum-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.129-136
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    • 2005
  • The deterministic analysis method has generally used to evaluate the slope stability and it evaluates the slope stability with decision value that is a representative value of design variables. However, one of disadvantages in the deterministic approach is there is not able to consider the uncertainty of soil strength properties, even though it is the biggest influential parameter of the slope stability. On the other hand, the limit state design(LSD) can take a consideration of uncertainties and computes both the reliability index and the probability of failure. LSD method is capable of overcoming the disadvantages of deterministic method and evaluating the slope stability more reliably. In this study, both the mean value and standard deviation of the internal land's representative soil strength properties applied to process the LSD method. The major purpose of this study is to gauge the general applicability of the limit state design in soil slope and to weigh the comparative validity of the proposed partial safety factor. In order to reach the aim of this study, the partial safety factor and resistance factor which totally satisfied the slope's overall safety factor were calculated by the load and resistance safety factor design (LRFD).

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Efficacy of Lens Shielding Device to Prevent Cataract with Radiotherapy for Orbit or Ocular Adnexal Tumor (안와 및 안부속기 종양의 방사선치료에서 백내장의 예방을 위한 렌즈보호 장치의 효용성)

  • Cho, Jung-Keun;Cho, Hyun-Sang;Han, Tae-Jong
    • The Journal of the Korea Contents Association
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    • v.7 no.12
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    • pp.139-144
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    • 2007
  • Radiotherapy which is the most effective for orbit lymphoma has been used increasingly due to the increase of orbit or ocular adnexal tumor patients. Curative effects and convalescence have been being more satisfied thanks to remarkable development of cancer chemotherapy and medical treatments, but side effects such as cataract, dry eye and retinopathy still break out. Thus, in this study, a Lens Shielding Device (LSD hereafter) was designed to prevent occurring of cataract due to radiation therapy for orbit lymphoma and its efficacy through dosimetry were evaluated. And in this paper, its manufacturing process was also explained. LSD is composed of a cover body covering the lens and a side fixing part supporting the cover body. To measure radiation, the patient therapy conditions were simulated and the measurement of the radiation was conducted with Thermo Luminescence Detector (TLD) and Markus chamber. The average TLD value was 5.7% and the TLD value and Markus chamber value were acquired as 4.2% and 5.1% respectively at 6 mm depth where zero lens center was located. Only 1.5Gy ($300Gy{\times}\;5%$) or 5% of total 30Gy with 9 MeV electron beam is estimated to affect on patient's lens. That is smaller dose than the threshold value of cataract (2GY) or the value (5Gy) that was reported to cause cataract in clinical conditions. Thus, these findings suggest that LSD be very useful for prevention of cataract during radiotherapy for malignant lymphoma of orbit and ocular adnexa. Furthermore, it might be possible to reduce patient's discomfort caused by alien substances and to make it easier to fix the device with customized manufacturing manners.

Control of Damping Forces by Side Clearance in Leaf Spring Damper (겹판스프링댐퍼에서 측면틈새에 의한 감쇠력 조절)

  • 김종수;김상도;제양규
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.06a
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    • pp.285-290
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    • 1999
  • This paper describes that the leaf spring damper(LSD) developed by authors can be controled by side clearance between side cover and leaf spring. The test rig and two prototype dampers with different side clearance were manufactured. Experiments were performed to investigate the effects of side clearance on the damping of leaf spring damper. The stiffness and damping coefficients are obtained from the displacements and the reaction forces generated by rotating the eccentric shaft. All dynamic coeffficients are plotted with the excitation frequency which is adjusted by rotating speed of shaft.

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A Statistical Approach for the Determination of Location and Range of Fishing Grounds in the Coastal Vessel Fishery (통계학적 접근에 의한 연안어업의 조업어장 위치 및 범위결정 에 관한 연구)

  • Kang, Y.J.;Kim, K.S.;Yi, S.B.
    • The Journal of Fisheries Business Administration
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    • v.38 no.1 s.73
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    • pp.97-113
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    • 2007
  • This study attempts to suggest a new approach of the the determination of location and range of fishing ground in the coastal vessel fishery using the anaiysis of variance(ANOVA) and least significant difference test(LSD test) in statistics. The important result of the empirical study is that there is no significant difference in fisfishing ground based on between fishermen's argument and spot investigation. But there is stastitically significant difference in fisfishing ground based on between fishermen's argument and the official documents of fishing records for past three years. The results suggest us that there exists a possibility of misuse of tax free oil providied for subsidizing fisheries. But because of the range limitation of data, it is impossible for us to generalize the above results.

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A Study on Result Analysis and Survey of User Requirements for Military Sleeping Bag (군용 침낭 사용자 요구에 맞춘 설문조사와 결과 분석)

  • Lee, Jeong Mun
    • Journal of Korean Society for Quality Management
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    • v.42 no.3
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    • pp.339-360
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    • 2014
  • Purpose: The objective of this paper was to analyze the requirements of the end-users by class after carrying out a survey on the user requirements for sleeping bags and utilize the result for effective product development. Methods: The test for difference in means by class was conducted through one sample analysis and one-way ANOVA after the survey result has gone through a reliability verification, and an LSD (Least Significant Difference) test was conducted as a post-mortem method. Results: A significant result was derived from the survey on the user requirements for sleeping bags by method of use, use of combination of sleeping bag components or a sleeping bag alone. Conclusion: The significant result derived from the survey of this paper on the user requirements for sleeping bags can be utilized for effective development of sleeping bags.

Establishment Technology of Leaves and Stems Dressing with Bermudagrass 'Konwoo' (버뮤다 그래스 신품종 ‘건우’의 LSD(Leaves and Stems Dressing = 잎줄기 드레싱) 시공기술)

  • 이재필;권영주;김석정;서한용;이상재;정종일;한인송;김두환
    • Asian Journal of Turfgrass Science
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    • v.15 no.3
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    • pp.137-146
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    • 2001
  • Stolen and rhizome are used as planting material fur sod production in hybrid types of bermudagrass. The new technology of Leaves and Stems Dressing (LSD) uses leaves and stems collected from mowing for sod production and turf establishment. The procedure of Leaf and Stem Dressing is as follows; 1) Collection of leaves and stems of bermudagrass using rotary mower with bucket. 2) Preparation of turf bed. 3) Dressing of leaves and stems of bermudagrass by man power or spray machine. 4) first irrigation. 5) Topdressing with sand or rotary with tractor. 6) Final irrigation.

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Analysis of Wastewater Reuse Effect on Field-Scale Water Quality (하수처리수의 농업용수 재이용에 따른 포장단위 수질영향 분석)

  • Seong, Choung-Hyun;Kim, Sung-Jae;Kim, Sung-Min;Kim, Sang-Min
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.4
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    • pp.59-65
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    • 2011
  • The purpose of this study was to analyze the water quality change when wastewater applied to study paddy fields. CREAMS-PADDY (Chemical, Runoff and Erosion from Agricultural Management System) model was used to estimate the field-scale water quality. Simulated results were compared with observed data monitored from Byeongjeom study paddy fields which is located near the Suwon sewage treatment plant in Gyeonggi-do. Significance analysis was performed for the three different irrigation water quality level and five fertilizer reduction scenarios using LSD (Least Significant Difference) and DMRT (Duncan's Multiple Range Test). Total nitrogen was found to be significant for both irrigation water quality level and fertilizer reduction while total phosphorus was not. Annual drainage load for total nitrogen was reduced by 66~92 % compared to irrigation load when treated wastewater irrigated to study paddy fields from 2002 to 2007. Total phosphorus was reduced by 70~86 %.

Lateral Stability Control for Rear Wheel Drive Vehicles Using Electronic Limited Slip Differential (전자식 차동 제한장치를 이용한 후륜구동 차량의 횡방향 안정성 제어)

  • Cha, Hyunsoo;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
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    • v.13 no.3
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    • pp.6-12
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    • 2021
  • This paper presents a lateral stability control for rear wheel drive (RWD) vehicles using electronic limited slip differentials (eLSD). The proposed eLSD controller is designed to increase the understeer characteristic by transferring torque from the outside to inside wheel. The proposed algorithm is devised to improve the lateral responses at the steady state and transient cornering. In the steady state response, the proposed algorithm can extend the region of linear cornering response and can increase the maximum limit of available lateral acceleration. In the transient response, the proposed controller can reduce the yaw rate overshoot by increasing the understeer characteristic. The proposed algorithm has been investigated via computer simulations. In the simulation results, the performance of the proposed controller is compared with uncontrolled cases. The simulation results show that the proposed algorithm can improve the vehicle lateral stability and handling performance.

Topology and size optimization of truss structures using an improved crow search algorithm

  • Mashayekhi, Mostafa;Yousefi, Roghayeh
    • Structural Engineering and Mechanics
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    • v.77 no.6
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    • pp.779-795
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    • 2021
  • In the recent decades, various optimization algorithms have been considered for the optimization of structures. In this research, a new enhanced algorithm is used for the size and topology optimization of truss structures. This algorithm, which is obtained from the combination of Crow Search Algorithm (CSA) and the Cellular Automata (CA) method, is called CA-CSA method. In the first iteration of the CA-CSA method, some of the best designs of the crow's memory are first selected and then located in the cells of CA. Then, a random cell is selected from CA, and the best design is chosen from the selected cell and its neighborhood; it is considered as a "local superior design" (LSD). In the optimization process, the LSD design is used to modify the CSA method. Numerical examples show that the CA-CSA method is more effective than CSA in the size and topology optimization of the truss structures.

The Effects of the Individual Application of Low Sodium Dialysate on Weight Gain, Blood Pressure, and Intradialytic Side Effects in Patients on Maintenance Hemodialysis (개별적 저나트륨 투석액 적용이 혈액투석 환자의 체중증가, 혈압 및 투석 중 부작용에 미치는 효과)

  • Song, Ji Sook;Kim, Eun Sook;Lee, Yu Na
    • Journal of Korean Clinical Nursing Research
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    • v.19 no.1
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    • pp.45-56
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    • 2013
  • Purpose: The purpose of this study is to identify the effect of low sodium dialysate (LSD) rather than conventional dialysate on interdialytic weight gain (IWG), blood pressure (BP), and intradialytic side-effects (ISEs) in patients on maintenance hemodialysis (HD). Methods: The study was performed in 43 patients, who were treated in the university hospital over 8 weeks. Each participant's serum sodium set point was measured using dialysate sodium 140 mEq/L during the first 4 weeks. For the next 4 weeks dialysate sodium concentrate (134,136,and138 mEq/L) was provided to each participant but only to an experimental group (EG) (n=22) based on the individual set point, although 140 mEq/L dialysate was given to all of the control group (CG) (n=21). Consequently, outcomes including IWG, BP, and ISE were evaluated. Results: In EG, difference of pre-HD SBP (p=.047) and post-HD serum sodium (p=.006) were significantly decreased compared to CG. Also, ISEs was not more frequent in EG. However, the differences were not statistically significant, IWG (kg & %), pre-HD DBP, post-HD SBP & DBP, and serum osmolality in EG. Conclusion: Individual application of LSD in patients on maintenance hemodialysis is beneficial to decrease pre-HD SBP and post-HD serum sodium without increasing ISE. Therefore, LSD can be better treatment than conventional dialysate.