• Journal of Community Nutrition
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• 제6권1호
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• pp.42-47
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• 2004

The purpose of the study was to investigate assisted living residents' perception of foodservice experience using a qualitative approach. A total of 14 residents who lived in assisted living units of a continuing care retirement community participated in interview sessions. The interviews were semi-structured with open-ended questions. The interviews were transcribed and coded to identify themes from the responses. The residents perceived the availability of choices, variety of foods, and service positively, but expressed concerns about food preparation, food quality, and repetitive menus. They were particularly concerned with tough and dry meats. The foodservice department should consider the older residents' ability to chew and their changing taste buds when determining quality of food purchased and preparation methods. The residents considered the service pleasing and described it as satisfactory. They stated that the service staff was friendly but needed more training in proper service techniques. Communication between the foodservice department and the residents was an area to be improved. The foodservice department should increase the residents' involvement in the menu planning and evaluation of the foodservice on a routine basis. Foodservice managers and dietitians working for the older adults can utilize the findings of the study to identify strategies to improve foodservice at their facilities

• Journal of Community Nutrition
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• 제6권1호
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• pp.41-47
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• 2004

The purpose of the study was to investigate assisted living residents' perception of foodservice experience using a qualitative approach. A total of 14 residents who lived in assisted living units of a continuing care retirement community participated in interview sessions. The interviews were semi-structured with open-ended questions. The interviews were transcribed and coded to identify themes from the responses. The residents perceived the availability of choices, variety of foods, and service positively, but expressed concerns about food preparation, food quality, and repetitive menus. They were particularly concerned with tough and dry meats. The foodservice department should consider the older residents' ability to chew and their changing taste buds when determining quality of food purchased and preparation methods. The residents considered the service pleasing and described it as satisfactory. They stated that the service staff was friendly but needed more training in proper service techniques. Communication between the foodservice department and the residents was an area to be improved. The foodservice department should increase the residents' involvement in the menu planning and evaluation of the foodservice on a routine basis. Foodservice managers and dietitians working for the older adults can utilize the findings of the study to identify strategies to improve foodservice at their facilities.

• 한국자동차공학회논문집
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• 제10권2호
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• pp.87-95
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• 2002

The aim of this article is to perform the numerical simulation far drop drag and breakup processes in air-assisted sprays using the Taylor analogy breakup (TAB) model with a modified drop drag model, in which a random method is newly used to consider the variation of the drop's frontal area. The predicted results for drop trajectory and Salter mean diameter (SMD) were compared with experimental data and the simulation results using the earlier published models such as TAH model, surface wave instability (Wave) model, and Wave model with original drop drag model. In addition, the effects of the breakup model constant, Ck, on prediction of spray behaviors were discussed. The results shows that the TAB model with the modified drop drag model is in better agreement with experimental data than the other models, indicating the present model is acceptable for predicting the drop breakup process in air-assisted sprays. At higher Weber numbers, the smaller Ck shows the best fitting to experimental data. It should be noted that more elaborated studies is required in order to determine the breakup model constant in the suggested model in the study.

• 한국레이저가공학회지
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• 제12권1호
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• pp.25-33
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• 2009

In laser-assisted machining (LAM), laser beam is used to locally increase the temperature of a workpiece and thus to enhance the machinability. In order to set the temperature of the material removal area of a workpiece at an optimal value, process parameters, such as laser power, feed rate, and rotational velocity, have to be carefully controlled. In this work, the effects of laser power and feed rate on the temperature distribution of a silicon nitride rotating at a constant velocity were experimentally investigated. Using a pyrometer, temperatures at various locations of the silicon nitride were measured both in circumferential and axial directions. The measured temperatures were fitted to a quadratic equation to approximate the temperature at the cutting location. The machining results showed that cutting force and tool wear were decreased when the temperature at the cutting location was increased.

• 한국통신학회논문지
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• 제33권12A호
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• pp.1217-1224
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• 2008

갈릴레오 위성시스템의 정확한 위치 확인을 위해서는 기본적으로 정화한 반송파 추적이 이루어져야 한다. 주파수 오차를 추적하기 위한 FLL은 전파 도달 시간의 변화를 발생시키는 동적 음력에 강인하지만 정확한 반송파 추적이 어렵다. 반면 위상 오차를 추적하기 위한 PLL은 정확한 반송파 추적이 가능하지만 동적음력에 약하고 높은 동적음력에서 반송파 추적성능이 저하된다. 본 논문에서는 갈릴레오 L1F 신호에서 높은 동적응력에서도 정확한 반송파 추적이 가능하도록 FLL과 PLL의 상호 보완적인 운용과 FLL지원의 PLL 루프필터를 적용한 반송파 추적루프를 설계하였으며, 모의실험을 통하여 제안한 기법의 성능을 입증하였다.

• 디지털콘텐츠학회 논문지
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• 제12권1호
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• pp.123-131
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• 2011

본 연구의 목적은 어휘 학습의 측면에서 컴퓨터 보조 학습을 통한 컴퓨터 기술의 효과와 유용성을 알아보고자 하는데 있다. 컴퓨터 기술을 통한 멀티미디어 수업은 네 가지 (듣기, 말하기, 일기, 쓰기의) 언어기술과 관련하여 다양한 언어학습방법을 제공한다. 한국인 영어 언어 학습자는 주입식 교육에 익숙해져 왔으며, 단어를 습득하는데 있어 반복적인 어휘 암기방법을 활용한다. 이를 위해 본 연구에서는 세 가지 연령 그룹을 대상으로 설문 조사와 교육용 멀티미디어 학습실험이 이루어져있다. 본 연구는 오프라인에서의 어휘학습과 다르게 교사는 컴퓨터 멀티미디어프로그램을 응용하여 교실 수준에 적합한 어휘 학습 응용 프로그램을 어떻게 효과적으로 개선 할 수 있는지 밝히고자 한다.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.3039-3045
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• 2013

Dual-frequency ultrasound assisted photocatalysis (DUAP) method was proposed to degrade a stable organic model effluent, cresol red (CR), using the prepared $Fe^{3+}$-doped $TiO_2$ with active carbon fiber loading ($Fe^{3+}-TiO_2/ACF$) as photocatalyst. The influence of key factors, including Fe doping amount and power density of dual-frequency ultrasounds (20/40 kHz), on the degradation efficiency was investigated. The degradation efficiency rises to 98.7% in 60 min accompanied by the color removal of CR liquid samples from yellow to colorless transparent at optimal conditions. A synergy index of 1.40 was yielded by comparison with single ultrasound assisted photocatalysis (SUAP) and the photocatalysis without ultrasound assisted (UV/$TiO_2$), indicating that a clear synergistic effect exists for the DUAP process. Obvious enhancement of degradation efficiency for the DUAP process should be attributed to production of large amount of free radicals by strong cavitational effects of dual ultrasounds.

• Composites Research
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• 제16권6호
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• pp.10-15
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• 2003

RTM 공정에 의하여 생성된 제품은 microvoids의 함유량에 의하여 기계적인 물성치에 큰 영향을 받는다. 본 연구에서는 이러한 microvoid의 형성과 이동을 실험적으로 관찰할 수 있는 방법을 제시하였다. Vacuum assisted RTM공정에서 유동선단에서의 microvoid의 형성과 이동을 DV camera로써 관찰을 한 후, 그것에서 void의 함유량을 구하고, 실험에서 얻어진 결과로 microvoid model에 필요만 factor들을 얻어낼 수 있었다. 이렇게 하여 얻어진 결과를 다시 실험적인 결과와 비교함으로써 서로 일치하는 결과를 얻어낼 수 있었다. 이번 연구에서 얻어진 결과를 수학적인 모델에 대입함으로써 VARTM 공정 중 microvoid의 함유량을 예측할 수 있다.

• 전자통신동향분석
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• 제35권2호
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• pp.38-49
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• 2020

In recent years, the unmanned aerial vehicle (UAV) assisted mobile free space optical (FSO) communication technique has attracted considerable attention regarding its aims to provide improved communication conditions for fixed-to-fixed FSO network and promising fronthaul and backhaul solutions for 5G+ wireless networks. This can be attributed to its outstanding advantages such as fast deployment and flexible network configuration. The UAV-assisted mobile FSO system can be used to provide cost-effective internet services in rural and remote areas and in hotspot areas that are characterized by increased data traffic. Additionally, it can be used to provide secure communication services under emergency circumstances. In this report, we review recent R&D trends in wireless network technology employing the UAV-assisted mobile FSO technique and key technologies for mobile FSO wireless networks. Furthermore, we introduce drone-based mobile FSO terminals and control systems that we have developed.

• 한국분무공학회지
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• 제3권4호
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• pp.58-64
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• 1998

In the gasoline engine of fuel injection type, atomization of fuel droplet and its distribution has directly influenced the performance of engine and harmful emission. To investigate atomization characteristics of fuel spray, in this paper fuel spray of air-assisted injector is observed at the various initial conditions of ambient air temperature and air assisted pressure. Behavior of fuel spray is photographed with microscopic visualization system. The SMD of fuel droplet is measured with PMAS (Particle Motion Analysis System). The effect of air-assisted pressure and temperature of ambient air resulted in the decrement of SMD and its variation. Finally, It was found that It was found that from spray angle at the two-hole injector had measured $20{\pm}4$ degree the result of photographs by shadow graphy. The mean diameter of suns decreased and the of droplets increased with increasing the temperature in the spray fields by the results of PMAS measurement. It was found that the characteristics of sprays became finer by increasing the temperature of spray fields about 373K without the delivery of air-assistance.