• 한국자동차공학회논문집
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• 제7권6호
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• pp.182-197
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• 1999

Described in this paper is an optimal driving control algorithm which focused on the improvement of fuel economy and the minimization of pollutant emissions in the parallel type hybrid drivertrain system for transit bus. For the energy balance among components such as engine, induction machine and buttery, the algorithm for power split ration determine is proposed. When it is implemented in the hybrid electric control unit(HECU) , using the sub-optimal method and the approximate technique , it is possible to save the memory , to shorten the calculation time, and to achieve the efficient driving actually. A Shift strategy for automated manual transmission is the other side of the driving control algorithm. It enables to select the optimal gear by using several shift maps which were predefined from the proposed method in this paper, As a results of driving simulation, it is proved that these algorithms make the hybrid drivetrain system to reduce fuel consumption and emissions considerably and to have the ability to the efficient use of battery.

• 한국자동차공학회논문집
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• 제16권2호
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• pp.87-92
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• 2008

The breakup processes and spray plume characteristics of liquid jets injected in subsonic air cross-flows were experimentally studied. The behaviors of column, penetration, breakup of plain liquid jet and droplet sizes, velocities have been studied in non-swirling cross-flow of air. Nozzle has a 1.0 mm diameter and Lid ratio=5. Experimental results indicate that the breakup point is delayed by increasing air momentum, the penetration decreases by increasing Weber number and the split angle is increased by increasing air velocity or decreasing injection velocity. SMD increases according as increasing height or decreases in accordance with increasing air velocity. This phenomenon is related to the momentum exchange between column waves and cross-flow stream. Droplet vector velocities were varied from 11.5 to 33 m/s. A higher-velocity region can be identified in down edge region at Z/d=40, 70 and 100. Lower-velocity region were observed on bottom position of the spray plume.

• Journal of the Optical Society of Korea
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• 제18권6호
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• pp.633-638
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• 2014

We report experimental behaviors of condensed $^{87}Rb$ atoms responding to changes in the trap potential of the atomchip. The two-types of adiabatic and non-adiabatic overall changes were implemented by changing the ramp-down speed of the chip-wire current, which can dominantly modify the one-axis magnetic field gradient. Under the adiabatic process, a pure condensate stayed in the initial spin state and collectively oscillated with both monopole and dipole modes, while an atomic cloud above the critical temperature exhibited sound waves in a dense ultracold gas. On the other hand, Bose-Einstein condensate atoms with non-adiabatic perturbation were split into spatially different positions by spin states through spin-flip. We investigated the split ratio among spin states depending on final evaporation frequency. Potential changes, of course, cause collective oscillations regardless of the changing process.

• Computers and Concrete
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• 제25권5호
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• pp.479-484
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• 2020

This work performed to analyses the impact of hooked end steel fibres on the mechanical properties of high performance concrete. The mechanical properties considered incorporate compressive strength, split tensile strength and flexural strength. Taking in to thought parameters, such as, volume fraction of fibres, fibre aspect ratio and grade of concrete, a logical strategy called Taguchi technique was utilized to discover the ideal blend of factors. L9 Orthogonal Array (OA) of Taguchi network comprising of three variables and three dimensions is utilized in this work. The evaluations of concrete considered were M60, M80 and M100. M60 contained 15% of metakaolin as bond swap though for M80 it was 5% of metakaolin and for M100 it was 10% metakaolin and 10% of silica smolder. The volume portion of fiber was fluctuated by 0.5%; 1% and 1.5% and the viewpoints proportions considered were 50, 60 and 80. The test outcomes demonstrate that incorporation of steel fibres enhance significantly the the strength characteristics of concrete, predominantly the splitting tensile strength and flexural strength. In light of relapse investigation of the test information scientific models were produced for compressive strength, split tensile strength and flexural strength of the steel fibre-reinforced high performance concrete.

• 한국자동차공학회논문집
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• 제13권1호
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• pp.90-98
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• 2005

HMT is a type of continuously variable transmission which has split power flow path characteristics with gear train and hydro static unit. The benefit of improved fuel economy and high power capacity enables it to be a promising application fur large vehicles. This paper presents the analysis results including velocity, static torque, transmission efficiency and dynamic model of the HMT that is developed for city buses. The speeds or gear shafts, the static clutch torque and split power ratio for each mode are detailed here. From the analysis of HMT transmission efficiency considering the power loss in meshed gear and hydraulic unit, we can conclude that minimization of hydraulic power is necessary for improved fuel economy design. Also, the dynamic simulation result for mode shift characteristics shows that little shift shock is observed because of the synchronized rotation speed in clutch.

• 전기학회논문지
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• 제59권2호
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• pp.355-358
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• 2010

As CMOS technology continues to scale down, signal processing is favorably done in the digital domain, which requires Analog-to-Digital (A/D) Converter to be integrated on-chip. This paper presents a design methodology of 12-bit 1-MS/s Rail-to-Rail fully differential SAR ADC using Deep N-well Switch based on binary search algorithm. Proposed A/D Converter has the following architecture and techniques. Firstly, chip size and power consumption is reduced due to split capacitor array architecture and charge recycling method. Secondly, fully differential architecture is used to reduce noise between the digital part and converters. Finally, to reduce the mismatch effect and noise error, the circuit is designed to be available for Rail-to-Rail input range using simple Deep N-well switch. The A/D Converter fabricated in a TSMC 0.18um 1P6M CMOS technology and has a Signal-to-Noise-and-Distortion-Ratio(SNDR) of 69 dB and Free-Dynamic-Range (SFDR) of 73 dB. The occupied active area is $0.6mm^2$.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제22권6호
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• pp.554-564
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• 2019

Purpose: This study verified the reliability and validity of the Diet Quality Index for Indian children (DQIIC). Methods: The study sample included 100 school going boys and girls (7-9 years). The dietary behavior of children was studied using a questionnaire and 24-hour dietary recall. The DQIIC comprises 21 items which aimed to assess the diet of Indian children on the basis of variety, adequacy of consumption of dietary components, and moderation in the amount of nutrients that are associated with diseases and dietary habits. The reliability of the DQIIC was assessed using the split half method, Cronbach's alpha, and test retest reliability. Content validity was evaluated using content validity ratio (CVR). Results: The intake of iron was found to be less than the recommended dietary allowances. There was frequent consumption of empty calorie packaged foods and higher than the recommended amount of sodium. Reliability of the DQIIC was 0.85 by split half method and the correlation coefficient for test retest reliability was 0.87. Cronbach's alpha was 0.62 and CVR was 0.85 for this index. Most of the children fell in the moderately healthy category. Conclusion: The DQIIC is a reliable and valid tool to assess the diet quality of Indian children between 7-9 years.

• Advances in concrete construction
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• 제3권1호
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• pp.55-69
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• 2015

Tailing Material (TM) and Fly Ash (FA) are obtained as waste products from the mining and thermal industries. Studies were carried out to explore the possibility of utilizing TM as a part replacement to fine aggregate and FA as a part replacement to cement, in concrete mixes. The effect of replacing fine aggregate by TM and cement by FA on the standard sized specimen for compressive strength, split tensile strength, and flexural strengths are evaluated in this study. The concrete mix of M40 grade was adopted with water cement ratio equal to 0.40. Concrete mix with 35% TM and 65% natural sand (TM35/S65) has shown superior performance in strength as against (TM0/S100, TM30/S70, TM40/S60, TM50/S50, and TM60/S40). For this composition, studies were performed to propose the optimal replacement of Ordinary Portland Cement (OPC) by FA (Replacement levels studied were 20%, 30%, 40% and 50%). Replacement level of 20% OPC by FA, has shown about 0-5% more compressive strength as against the control mix, for both 28 day and 56 days of water curing. Interestingly results of split tensile and flexural strengths for 20% OPC replaced by FA, have shown strengths equal to that of no replacement (control mix).

• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권2호
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• pp.117-129
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• 1997

Recently, combined with social complexity, increment of medical demand and supply and the change of esthetic category, admission and operation of the patients of facial deformity have been changed with annual change. This study was conducted in the concept of helping the overall character of orthognathic surgery in future understood and being an important index in the establishment of better treatment course, through the patient, on whom was operated orthognathic surgery via sagittal split ramal osteotomy in our Dept. of Oral & Maxillofacial Surgery, Chonbuk National University Hospital from 1991. 1. 1 to 1995. 12. 31. The results were obtained as follows. 1. The ratio of male to female was 1 : 1.33 and the ages between 16 and 25 year was 73.6%, and the mean age was 20.4 years. 2. The ratio of setback amount between 6 to 15mm was 84.6% and the advancement amount between 1 to 10mm was 89% and the mean amount of movement was 9.0mm in setback, and 3.6mm in advancement. 3. After removal of maxillomandibular fixation(MMF), the distinction of sex was not statistically significant in ROM. 4. The ROM following methods of fixation was statistically significant in 3rd(P<0.05), 8th, and 12th week(each P<0.01), with faster rehabilitation in rigid fixation which had shorter MMF period. 5. The rehabilitation of ROM following the operation methods was statistically significant in 1st(P<0.05), 2nd, 3rd, 4th, 6th, 8th, and 12th week(each P<0.01) with faster rehabilitation in the case of SSRO than Lefort I / SSRO (Two jaw surgery). 6. The rehabilitation of ROM following directions of mandibular movement did not manifest a statistically significant difference in both setback and advancement.

• 한국전자파학회지:전자파기술
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• 제2권2호
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• pp.19-24
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• 1991

본 논문에서는 태극 모양의 새로운 방향성 결합기를 고안하여 높은 전력 분배율을 실현할 수 있음을 실험을 통하여 입증하였다. 제안돈 태극형 방향성 결합기는 하이브리드 링형 방향성 결합기의 $3\lambda/4$부분을 적극적으로 활용하기 위하여 태극 모양의 구조를 취했으며, 우수 기수 모드 해석법을 이용하여 완전정합과 분리 조건을 만족하는 각 지로의 어드미턴스를 구하였다. 그 결과 마이크로 스트립 라인으로 제작 가능한 저항의 범의 내에서 이미 발표된 연구 결과에서와 같은 크기의 회로 면적내에서도 훨씬 높은 전력 분배율(최대 28DB)을 실현할 수 잇음을 알았으며, CGP-502기판을 이용하영 중심 주파수 10GHz에서 0,8,16dB 전력 분배율을 갖는 태극형 방향성 결합기를 설계 제작하고 실험을 하여 이론의 타당성을 확인하였다.