• Title/Summary/Keyword: Down-time

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Analyses of on-the-fly generation of spectral superhomogenization factors for multigroup whole core calculation employing pin-wise slowing-down solutions

  • Seungug Jae;Han Gyu Joo
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.1084-1096
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    • 2023
  • On-the-fly(OTF) generation of Spectral Superhomogenization(SSPH) factors is analyzed in the multigroup(MG) whole core calculation employing pin-wise continuous energy(CE) slowing-down solutions. The motivation for the work is to avoid the huge computing time required for the generation of a parametrized SSPH factor library(PSSL) which is used to resolve the angular dependency of MG resonance cross sections, and also to exploit the advantage of flexible choice of a MG structure by using CE slowing-down solutions. Two pin-wise CE slowing-down methods, the equivalent Dancoff cell method and the shadowing effect correction method, are evaluated with the OTF SSPH method. The effectiveness of the OTF SSPH method is examined for various simplified and realistic core problems with various MG structures. It is demonstrated that the computing time overhead of this method is negligible whereas the solution accuracy is considerably enhanced.

The Effect of Prior Price Trends on Optimistic Forecasting (이전 가격 트렌드가 낙관적 예측에 미치는 영향)

  • Kim, Young-Doo
    • The Journal of Industrial Distribution & Business
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    • v.9 no.10
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    • pp.83-89
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    • 2018
  • Purpose - The purpose of this study examines when the optimism impact on financial asset price forecasting and the boundary condition of optimism in the financial asset price forecasting. People generally tend to optimistically forecast their future. Optimism is a nature of human beings and optimistic forecasting observed in daily life. But is it always observed in financial asset price forecasting? In this study, two factors were focused on considering whether the optimism that people have applied to predicting future performance of financial investment products (e.g., mutual fund). First, this study examined whether the degree of optimism varied depending on the direction of the prior price trend. Second, this study examined whether the degree of optimism varied according to the forecast period by dividing the future forecasted by people into three time horizon based on forecast period. Research design, data, and methodology - 2 (prior price trend: rising-up trend vs falling-down trend) × 3 (forecast time horizon: short term vs medium term vs long term) experimental design was used. Prior price trend was used between subject and forecast time horizon was used within subject design. 169 undergraduate students participated in the experiment. χ2 analysis was used. In this study, prior price trend divided into two types: rising-up trend versus falling-down trend. Forecast time horizon divided into three types: short term (after one month), medium term (after one year), and long term (after five years). Results - Optimistic price forecasting and boundary condition was found. Participants who were exposed to falling-down trend did not make optimistic predictions in the short term, but over time they tended to be more optimistic about the future in the medium term and long term. However, participants who were exposed to rising-up trend were over-optimistic in the short term, but over time, less optimistic in the medium and long term. Optimistic price forecasting was found when participants forecasted in the long term. Exposure to prior price trends (rising-up trend vs falling-down trend) was a boundary condition of optimistic price forecasting. Conclusions - The results indicated that individuals were more likely to be impacted by prior price tends in the short term time horizon, while being optimistic in the long term time horizon.

Development of Opened Slab Method for Top-Down Construction (지하역타공법용 개방형 슬래브 개발)

  • Song, Jee-Yun;Rhim, Hong-Chul;Kang, Doo-Hyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.05a
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    • pp.43-46
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    • 2008
  • In Top-Down construction for underground structures, the placement of slab as a horizontal supporting member against lateral earth pressure is an important process in determining construction time and cost. Usually, a reinforced concrete perimeter girder distributes concentrated lateral loads from earth retaining structures such as Cast-in-place (CIP) piles. By combining the function of the R/C perimeter girder and horizontal slabs, the Opened Slab Method is efficient for reducing construction time by elimination of time-consuming formwork for traditional perimeter girders. The structural performance of the method is also discussed in this paper.

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The Kinematics Analysis of Round-off at end of Beam-salto Backward Stretched with Step-out to Cross on Balance Beam (평균대 도움 짚고 몸 펴 뒤 공중 돌아 오르기 동작에 대한 운동학적 분석)

  • Kim, Young-Ran
    • Korean Journal of Applied Biomechanics
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    • v.13 no.3
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    • pp.99-116
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    • 2003
  • The purpose of this study was to kinematics factors on during round-off at end of beam-salto backward stretched with step-out to cross on balance beam. Four elite female gymnastics players participated as subject of this study. The methods of this study was analyzed using three dimentional analysis. The results and conclusion of this paper is obtained as follows ; 1. The phase of time was the most short time in board touch down phase and board take-off phase. Also, it was shown a more long time in total time compared to previous study. 2. The horizontal displacement of each phase was shown the most high levels in balance beam landing. The vertical displacement was display a non-linearity increase in board take-of phase, and it was shown the most high levels in vertical displacement during landing of balance beam. 3. The horizontal velocity of each phase was shown the most high levels in board touch down, and it was display a gradually decreased levels because flight during board take-of. The resultant velocity of CG on each phase was shown the most high levels in board touch down and board take-off. 4. The angle of hip joint was shown the most high levels as performed a motion in extension state during board take-off, and the angle of knee joint was display a increased levels because of flight cause body extension in board take-off. Also the angle of ankle joint was shown a increasing levels during board take-off. Considering to this results, it is suggest that the change of kinematics factors in board touch down and board take-off is key role on the effective board control.

Anthelmintic and Analgesic Activities of Trachyspermum Khasianum H. Wolff

  • Sutnga, Innocent;Marbaniang, Balari;Hazarika, Gautom;Goswami, Priyanka;Choudhury, Ananta
    • Journal of Pharmacopuncture
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    • v.23 no.4
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    • pp.230-236
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    • 2020
  • Objectives: Trachyspermum khasianum H. Wolff is a rare medicinal plant characteristically used by the traditional healers in traditional medicine for the treatment of throat-pain, toothache, and stomach ache. The study was designed to determine the anthelmintic and analgesic properties of the aerial parts of Trachyspermum khasianum H. Wolff (Family: Apiaceae). The aqueous and ethanol extract of T. khasianum H. Wolff was prepared and subjected for evaluation to determine the possible therapeutic effects. Methods: Anthelmintic activities of the extracts were determined by observing the time taken to paralyze and the time taken for the death of earthworms (Eisenia foetida) as compared to the standard drug-Albendazole (20 mg/ml) and control. Analgesic potential of the extracts was evaluated using Eddy's hot plate method to understand the analgesic activity in rats (Wistar rats) at 100 mg/kg and 200 mg/kg body weight doses and compared with the standard reference (Diclofenac sodium: 10 mg/kg of animals). Results: The extracts showed a significant dose-dependent anthelmintic effect at the different concentrations (10, 20, and 40) mg/ml, compared to that of the standard drug (20 mg/ml). Also, the results suggested that the plant extracts possess significantly analgesic activity in rats. Conclusion: The studies indicate that Trachyspermum khasianum shows anthelmintic and potent analgesic activities. Further research should be carried out to identify the specific phytoconstituents responsible for both analgesic and anthelmintic activities and its possible mechanism of action.

A Study on an Operational Availability Computation Model for Weapon Systems (무기체계 운용가용도 산정 모델에 관한 연구)

  • Kim, Hye-Lyeong;Baek, Soon-Heum;Choi, Sang-Yeong
    • Journal of the military operations research society of Korea
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    • v.35 no.3
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    • pp.17-30
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    • 2009
  • In this study, we propose the operational availability computation model that can be used on the weapon system's requirement planning phase. The proposed model consists of the time parameters of Ao(Operational Availability) for a system and each time parameter's estimation method. The time parameters for Ao computation are TT(Total Time) and TDT(Total Down Time). The time parameters are defined by considering OMS/MP(Operational Mode Summary/Mission Profile) elements. TT is a calendar time as a specific mission time at wartime or one year at peacetime. TDT consists of TPM(Total Preventive Maintenance time), TCM (Total Corrective maintenance time), TALDT(Total Administrative and Logistics Down Time). Then the estimation method for these time parameters are presented by the weapon systems types.

Definition of the Earth-volume in Breakwater Using Real-time DGPS & Echo-Sounding data (실시간 DGPS & Echo-Sounding 데이터를 이용한 방파제사석투하 토공물량 확인)

  • 서용운;최윤수
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.18 no.4
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    • pp.343-350
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    • 2000
  • This study deals with the Definition of the Earth-volume quantity and direction of throwing down stones (Q.R.R) into the Breakwater using Real-time DGPS & Echo-Sounding method. Generally, the buoy in the center line of Breakwater has been set up so as to throw down stones in the correct area. After throwing stones down there, surveyors have been surveying the depth and direction of stones with rod and sounding lead. The method, however, is not effective because of long time and a lot of human power, in addition it is incorrect. This paper has studied on the solution of those problems using Real-time DGPS & Echo-Sounding data to calculate the earth-volume quantity, direction and depth of throwing down stones. This paper says the effective and economical methods using Real-time DGPS & Echo-Sounding data there.

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Development of a Down-alternative Outdoor Jacket design (다운대체 아웃도어 재킷의 디자인 개발)

  • Lee, Dal A;Moon, SunJeong;Chung, Sham Ho
    • Journal of the Korean Society of Costume
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    • v.63 no.8
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    • pp.143-155
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    • 2013
  • The outdoor apparel market has been growing very fast recently, and consumers are spending more time doing outdoor activities for their leisure. As the outdoor apparel market is growing, it has started to combine functionality with style to provide more diverse designs and colors for all ages. The increase of interest in heathy life-styles, outdoor activities, and leisure has lead to a rise in demand for outdoor apparel. Now outdoor apparel have become a part of people's daily casual wear in addition to being worn for outdoor activities. This study is focused on a outdoor jacket design which is used as down-alternative material and the purpose of this study is to design outdoor jackets using a down-alternative fabrics that improve the thermal and lightweight effects for clothing comfort, and increase the satisfaction of wearing down-alterative outdoor jacket. The research of this paper was done by using a questionnaire survey. The survey was used to examine the male customers' outdoor activities, purchase behaviors, place, expense and design preferences. Then, down-like fabric was used to make the prototype down jacket and its design, function, and satisfaction with wearing compared with other brands down jacket products were analyzed. Although duck down fabrics are representative of outdoor jackets, they have many problems that need to be solved such as feathers falling out or its vulnerability to moisture. They have competitive prices compared to down jackets so down-alternative jackets are able to gain more proportion of its market share.

Mathematical modeling study for the stagnation pressure control system of the blow-down type wind tunnel (불어내기식 풍동의 정체실 압력제어 시스템 모델링)

  • 김영준;권정태
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.206-211
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    • 1992
  • A mathematical model of the blow-down type wind tunnel is developed in order to design the controller which controls the stagnation pressure being used to obtain the setpoint Mach Number. The motion of compressible fluids in the tunnel is modeled using the one-dimensional gasdynamics. The time responses of the wind tunnel states, such as pressures, mass flow rates, and valve open area, are investigated by digital computer simulation. By the simulation study it is shown that the real blow-down wind tunnel can be simulated by the obtained mathematical model.

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Development of Top-Down Connection System to Solve the Problem of Construction Tolerances in Installing Prefabricated Beams to Pre-founded Columns (시공오차가 있는 선기초기둥에 공장제작보의 설치가 용이한 탑다운공사용 접합기술개발)

  • Kim, Seung-Weon;Jung, Hee-Weon;Park, Dae-Yung;Kim, Dong-Gun;Park, Joo-Hyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05b
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    • pp.25-30
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    • 2011
  • Almost prefounded columns for top-down construction certainly have construction tolerances in plan and plumbness. Therefore, it is very difficult to connect prefabricated beams to prefounded columns at each floor level after excavation by usual top-down connection method and this usual connection method leads to long construction time, increasing cost and decreasing quality. This paper presents a new method for connecting prefabricated beam to prefounded column with GROUT-JACKET CONNECTION SYSTEM consisting of sleeve, bearing-shear bands and grout. Details and illustrations of the connections and applications by GROUT-JACKET CONNECTION SYSTEM for the top-down construction are also included in this paper.

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