• 상하수도학회지
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• 제34권5호
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• pp.311-321
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• 2020

In this study, a model to optimize residual chlorine concentrations in a water supply system was developed using a multi-objective genetic algorithm. Moreover, to quantify the effects of optimized residual chlorine concentration management and to consider customer service requirements, this study developed indices to quantify the spatial and temporal distributions of residual chlorine concentration. Based on the results, the most economical operational method to manage booster chlorination was derived, which would supply water that satisfies the service level required by consumers, as well as the cost-effectiveness and operation requirements relevant to the service providers. A simulation model was then created based on an actual water supply system (i.e., the Multi-regional Water Supply W in Korea). Simulated optimizations were successful, evidencing that it is possible to meet the residual chlorine concentration demanded by consumers at a low cost.

• 한국소음진동공학회논문집
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• 제21권8호
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• pp.720-725
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• 2011

Most ultrasonic vibration cutting tools are operated at the resonance condition of the longitudinal vibration of the structure consisting of booster, horn and bite. In this study, a transverse vibration tool with beam shape is designed to utilize the vibration characteristics of the beam. Design point of the transverse vibration tool is to match the resonance frequency of the bite to the frequency of the signal to excite the piezoelectric element in the booster. The design process to match the natural frequency of the longitudinal vibration mode of the horn and that of the transverse vibration mode of the bite is presented. Dimensions of the horn and bite are searched by trend analysis through which the standard shapes of the horn and bite are determined. After the dimensions of each component of the cutting tool consisting of booster, horn and bite are determined, the assembled structure was experimentally tested to verify that true resonant condition is achieved and proper vibrational displacement are obtained to ensure that enough cutting force is generated.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.208-216
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• 2004

The waterhammer occured when the pumps are started or stopped for the operation or tripped due to the power failure, the hydraulic transients occur as a result of the sudden change in velocity. The field tests of the waterhammer were carried out for PanGyo booster pumping station. The PanGyo pumuing station was installed booster pump of 6 sets and in-line pump of 2 sets. The main surge suppression device was equipped with the pump control valve and the surge relief valve as auxiliary. However, the pump control valve had not early controlled in the planned closing mode, and the slamming occurred to the valve of which abruptly closed during the large reverse flow. Because the pressure wave caused by the pump failure was superposed on the slam surge, the upsurge increased so extremely that the shaft of the valve was damaged. After the addition surge suppression device was equipped with air chamber. Further more in-line pump is needed surge suppression device that the pumping station acquired the safety and reliability for the pressure surge.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.151-156
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• 2008

Water flow characteristics of an apartment complex consisting of 12 buildings and 635 units in total have been investigated numerically. The complex incorporates two zone booster pump water supply system, and some units have pressure reducing valves in them. Input data to a commercial code Flowmaster7 include survey results on the water usage for the last three years, dimension of the water supply system and its operation condition, etc. Calculated static pressures at the inlet of all units are compared with their design and measured counterparts, and they agree quite well with each other. Then, the pressure distributions and volumetric flow rates at all 635 units are estimated. Flow balancing is also attempted by varying the ratio of angle valve of each unit to improve the non-uniformity of flows.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.742-748
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• 2004

In this paper are presented TSTO system analysis including some controlled variables on the engine operation such as a fuel flow rate and a pressure ratio of compressor, as well as variables on the trajectory. TSTO studied here is accelerated up to Mach 6 by a fly-back booster powered by air breathing engines. Three different types of engine cycle were treated for propulsion system of the booster, such as a turbo ramjet, a precooled turbojet and an EXpander cycle Air Turbo Ramjet (ATREX). The history of the controlled variables on the engine operation was optimized by Sequential Quadratic Programming (SQP) to accomplish the minimum fuel consumption. The trajectory was also optimized simultaneously. The results showed that the turbo ramjet gave the best fuel consumption. The optimal trajectory was almost the same except in the transonic range and just before reaching to Mach 6. The history of the pressure ratio of compressor considerably depended on the engine type. It is concluded that simultaneous optimization for engine control and trajectory is effective especially for a high-speed airplane propelled by turbojets like the TSTO booster.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.266-267
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• 2017

본 연구에서는 중첩된 두 비행물체에서 단분리 시 일어나는 주위 유동장 해석에 초점을 맞춰 해석을 수행하였다. 수치적인 해석을 위하여 정지된 비행체에서 분리되는 실린더 형태의 부스터를 중첩격자를 이용하여 모델링 하였으며 상용해석코드인 CFD-FASTRAN$^{TM}$을 사용하여 계산하였다. 실제 현상을 모사하기 위하여 경계조건 및 외력을 도출하였으며 각 비행조건에 따른 부스터 분리 시 주위 유동장 해석을 수행하였다. 단분리 시의 비행속도와 받음각 조건에 대한 해석결과를 이용하여 실제 분리 현상을 모사할 수 있는 수치적인 경계조건을 파악하고 안전한 단분리 예측에 본 연구결과를 활용하고자 한다.

• 전력전자학회논문지
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• 제4권6호
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• pp.531-538
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• 1999

본 논문에서는 퍼지 논리에 기초를 둔 DC-DC converter를 위한 범용 FLC는 기존의 제어기와 비교할 때, 오버슈트 문제와 파라메터 변화에 대한 민감도 면에서 향상된 성능을 나타내었다. 이러한 성능 향상은 FLC 규칙들이 다양한 동작 영역에서 각각 적합하게 설정됨으로써 소신호 응답과 대산호 응답 모두 효과적으로 동작하도록 설계되었기 때문이다. 그 적용 예로 부스터(booster)에 대한 시뮬레이션 결과는 제안된 제어 기법의 타당성을 보여주고 있다.

• 자동차안전학회지
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• 제16권1호
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• pp.21-28
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• 2024

Many global car manufacturers in the world are recently developing a variety of electric vehicles in response to demanding market needs. Also, they have adapted the architecture method in order to develop electric vehicles effectively. It is because architecture method can produce various electric vehicles with high profitability. However, when electric vehicles are being developed, brake system has a lot of demanding tasks in relation to deciding specification of brake system because of heavy vehicle weight, narrow power electric room space and large volume of electric hydraulic booster. In this paper, a new approach is proposed for deciding the front and rear brake systems in order to design the brake system of electric vehicles effectively. To do this, we study correlations among vehicle weight, layout of power electric room and volume of electric hydraulic booster. And then, we also study combination of hydraulic braking and regenerative braking which is widely applied to electric vehicles. Finally, we want to contribute to build up modular design of brake system for architecture of electric vehicles through these studies.

• Clinical and Experimental Vaccine Research
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• 제11권2호
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• pp.184-192
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• 2022

The coronavirus disease 2019 (COVID-19) pandemic revolutionized the vaccine market and initiated the momentum for alternative routes of administration for vaccines. The intranasal route of immunization is one such possibility that appears to be the most promising since it has some significant advantages, particularly in the prevention of respiratory infection. To analyze and summarize the role of nasal vaccines over conventional vaccines during COVID-19 and the need for the nasal vaccine as a booster shot. In this narrative review, the required data was retrieved using keywords "COVID-19," "Intranasal," "Immunity," "Nasal spray," and "Mucosal" in databases including PubMed, Scopus, Embase, Science Direct, and Web of Sciences. The results of the study showed that the nasal vaccines were both effective and protective according to the current researches approaching during the COVID-19 period and the preclinical and clinical phase trials prove the intranasal vaccination elicits more robust and cross-protective immunity than conventional vaccines. In this narrative review article, mechanisms across the nasal mucosa will be briefly presented and the current status of nasal vaccines during the COVID-19 pandemic is summarized, and advantages over traditional vaccines are provided. Furthermore, after exploring the primary benefits and kinetics of nasal vaccine, the potential for consideration of nasal vaccine as a booster dose is also discussed.

• Pediatric Infection and Vaccine
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• 제5권1호
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• pp.67-68
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• 1998