• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2002년도 제7차 학술대회 초록집
• /
• pp.82-82
• /
• 2002

목적： Phase cycling과 fat suppression을 기존 STEAM 펄스시퀀스에 추가 및 최적화함으로써 3.0T 1H MRS 스펙트럼의 quality를 향상시키는 데 그 목적이 있다. 대상 및 방법： 가톨릭의대에 설치된 3.0T MRI를 이용하여 STEAM 펄스시퀀스를 최적화하였다. 우선 CHESS 펄스시퀀스를 이용하여 물 신호를 억제하고, 대사물질의 신호에 영향을 주는 fat 신호를 제거하도록 펄스시퀀스 최적화를 시험하였다. 또한 Phase cycling을 이용하여 Noise 신호를 제거하였다. 스펙트럼을 분석하기 위하여 본 사에서 개발한 MaqSpec 프로그램을 이용하였고, Post-processing을 한 후 펄스시퀀스 변경 전후의 MRS 스펙트럼을 비교하였다.

• 한국게임학회 논문지
• /
• 제18권6호
• /
• pp.69-82
• /
• 2018

최근 들어 VR 산업의 성장을 위한 양질의 VR 콘텐츠에 대한 필요성이 꾸준히 제기되고 있다. 이에 본 연구는 VR 콘텐츠 중에서 가장 큰 주목을 받고 있는 VR 게임의 사용자의 관심요소에 대해 연구하였다. 연구 수행을 위해 스팀(STEAM)의 사용자 리뷰 데이터를 활용하였고 리뷰 데이터에 텍스트마이닝과 네트워크 분석을 적용한 결과 VR 게임 사용자의 관심요소는 '현존감', '1인칭 시점 게임', '청각적 요소', '상호작용' 으로 확인되었다. 본 연구는 양질의 VR 게임 개발을 위한 사용자 관점의 연구를 수행하고 사용자 관점의 연구를 리뷰을 통해 시도한 초기 연구라는 것에 대해 그 의의가 있다.

• 한국축산식품학회지
• /
• 제37권3호
• /
• pp.410-417
• /
• 2017

The effect of dietary fiber enrichment (wheat bran) and cooking methods (oven, steam and microwave) on functional and physico-chemical properties of raw nuggets formulation as well as nutritional, color and textural properties of chicken nuggets were analyzed in this study. Among different cooking methods used for nuggets preparation, steam cooked nuggets had significantly (p<0.05) higher water holding capacity (56.65%), cooking yield (97.16%) and total dietary fiber content (4.32%) in comparison to oven and microwave cooked nuggets. The effect of cooking methods and wheat bran incorporation was also noticed on textural properties of the nuggets. Hardness, firmness and toughness values of oven and steam cooked nuggets were significantly (p<0.05) higher than microwave cooked nuggets. Among nuggets prepared by different cooking methods, cohesiveness of microwave cooked nuggets was found to be significantly (p<0.05) highest, whereas, oven cooked nuggets had significantly (p<0.05) highest gumminess and chewiness values. Steam cooked nuggets were found to be better among all nuggets due to their higher cooking yield and dietary fiber content.

• 한국가시화정보학회지
• /
• 제14권2호
• /
• pp.18-24
• /
• 2016

This paper presents an experimental investigation to visualize cross-sectional two-phase flow structure and identify liquid-gas interface for condensation of steam at a low mass flux in a slightly inclined tube using the axial-viewing technique, which permits to look directly into flow during condensation of steam. In this technique, two-phase flow is viewed along the axis of a pipe by locating a high-speed video camera in front of a viewer that is fitted at the outlet of the pipe. A short section of the pipe is illuminated and is recorded through the viewer, which is kept free of liquid by mildly introducing air. Experiments were conducted in a pipe of 19.05 mm in inner diameter at atmospheric pressure. Cross-sectional two-phase flow structure is obtained at a steam mass flux of $2.62kg/m^2s$ as a function of steam quality in the range from 0.5 to 0.9. The results show that stratified-wavy flow is a unique flow pattern observed in the scope of the present study. Condensate film thickness, stratification angle and void fraction were measured from the obtained flow structure images. Finally, heat transfer coefficient was calculated using the measurement data and discussed in comparison with existing correlations.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 추계학술대회 논문집
• /
• pp.354-357
• /
• 2005

When Ti-6Al-4V is used in long steam turbine blades, the main issues are how to improve the fatigue strength as a problem of internal quality and how to forge the thinnest possible blades as problem of dimensional precision. To assure an excellent fatigue strength, it is important to make the two phase fine and equiaxial structure by providing enough plastic deformation in the two phase$(\alpha\;phase/\beta\;phase)$ temperature region. Accordingly, it needs to predict that forging temperature, preform design and forging velocity in forging process. To achieve this end, the two steps forging process was suggested to forge the thin and twisted blades with a precision hammer considering die forces and metal flow. Two steps forging process consists of the flattening forging process and finishing forging process. Process in forging of a 1016mm long steam turbine blade is designed by the finite element method. This study attempts to derive systematic design procedures for process design in the forging. Forging parameters was analyzed in two-dimensional plane-strain simulation and two steps forging process carried out in three-dimensional simulation. Consequently, optimal forging process parameters of long steam turbine blades in Ti-6Al-4V with a high dimensional precision are selected in the hammer die forging.

• 동력기계공학회지
• /
• 제15권5호
• /
• pp.22-29
• /
• 2011

In this study, the damage mechanism of large scale steam turbine due to water induction was analyzed and recovery characteristics were reviewed. A turbine consists of the rotating rotor and the stationary casing, and the clearance between them is very small for the efficiency enhancement. If water induction, while relatively cold steam or water is introduced into turbine, occurs, the considerable humping is caused at the casing near the initial water induction point and that induces the rubbing between rotor and casing. Finally, it leads to the catastrophic failure. Bowed rotor has the different characteristics in the recovery depending on damage degree. The elastic deformation due to light rubbing is recovered by turning the rotor with 3 rpm under normal operation condition, but most plastic deformation due to rubbing deforms the local microstructure and that results in permanent deformation which could not be recovered under normal operation condition. Bowed rotor has diverse characteristics depending on the recovery method, and the method is empirical and needs the cutting edge technology. Careful recovery treatment of the rotor will eliminate the risks and secure the high quality rotor similar to new rotor. If any critical error is made during the recovery, the rotor would not be recovered permanently and it should be scrapped.

• 디지털융복합연구
• /
• 제19권8호
• /
• pp.75-88
• /
• 2021

4차산업혁명 시대의 도래와 더불어 융합형 인재양성의 중요성이 부각 되고 있고 이러한 교육을 담당할 예비교사들의 융합수업(STEAM) 구성 능력의 함양이 양질의 미래 교육을 담보할 이슈로 떠오르고 있다. 이에 본 연구는 진정한 융합교육이 이루어지기 위해서는 교수자의 면밀한 피드백의 역할과 기능이 예비교사들의 역량 강화에 주요한 요소임을 제시하며, 교육학에 있어서 피드백에 관한 제반 이론이 이러닝을 활용한 대학 수업에서 예비교사들의 융합적 지식형성을 어떻게 지원하는지를 분석하였다. 예비교사들은 STEAM 수업지도안을 작성하는 과정에서 4단계의 조별 활동과 그에 걸맞은 피드백을 제공 받았으며 5단계에서는 이를 바탕으로 개별 수업지도안을 완성하였다. 수업지도안의 완성 후에는 설문조사를 실시하여 예비교사들의 인식을 조사하였다. 단계별로 적용된 통합적 피드백의 세부적 내용과 융합적 수업구성 역량의 향상 과정을 사다리이론을 근거로 하여 모델링 하였다. 이러한 전략적 모형은 예비교사들의 융합적 지식과 역량을 제고할 뿐 아니라 그들의 성취도와 만족도 향상에도 기여하였다.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2008년도 Asian Magnetics Conference
• /
• pp.208.1-208.1
• /
• 2008

• 한국수처리학회지
• /
• 제26권6호
• /
• pp.99-107
• /
• 2018

This research has developed a high temperature steam cleaning technology using a ceramic membrane with durability against temperature and pressure conditions. In steam cleaning, steam of $120^{\circ}C$ is injected into the ceramic membrane to induce pyrolysis by the endothermic reaction to remove fouling from the membrane. The water quality of raw water was adjusted to turbidity 10, 25 NTU and DOC 2.5 mg/L, and the membrane was uniformly fouled by constant pressure operation at 100, 200, and 300 kPa. Physical backwashing was performed with water and air at a pressure of 500 kPa and steam at $120^{\circ}C$ was injected for 0 to 5 minutes. As the turbidity concentration and the operating pressure increased, the flux decreased by 0.7 to 14.4%. It is confirmed that 10.7 to 53.8% recovery is possible than physical cleaning at the injection of steam for 3 minutes, so it is considered that the steam cleaning of the ceramic membrane is effective. Compared with CEB after NaOCl (300 mg/L) filtration at 25 NTU and 300 kPa of turbidity, the steam cleaning result for 3 minutes was similar to 46.7% of CEB for 3 hours. It has been confirmed that steam cleaning is suitable for a ceramic membrane having excellent heat resistance against high temperature. It was considered to have better cleaning efficiency as compared with general physical backwashing.

• 한국식품조리과학회지
• /
• 제14권4호
• /
• pp.358-366
• /
• 1998

To meet the demand for high quality of foods with the expanded implementation of foodservice into kindergarten, and to make the efficient use of resources, the necessity of introducing central production unit with cook/chill system into kindergarten foodservice is getting increased. The purpose of this study were to develop standardized recipe applicable to cook/chill system for kindergarten foodservice and to evaluate the microbial and sensory quality. For quantitty production of cook/chill system in kindergarten foodservice, Various Bulkogis were selected as menu items. The followings are summary of the results： 1. Standard recipes to produce Various Bulkogis(Broiled Sliced Meat with Sauce) for cook/chill system have been developed. 2. The microbial quality of Various Bulkogis during 10 days chilled storage was very good. And in this experiment, the stability of storage of standard recipes of Various Bulkogis at cook/chill system was proved for 10 days. 3. All of the items of sensory evaluation of Bulkogis has no significance between the first day and the third day of storage, except the color of Pork Bulkogi (P<0.05).