• 제목/요약/키워드: Single case study

검색결과 2,455건 처리시간 0.033초

인터넷쇼핑몰의 의류상품정보 제시방법에따른 쇼핑가치와 만족 (Shopping Value and Satisfaction by Presentation Formats of Apparel Products -Information on Internet Shopping Malls)

  • 유은영;이유리
    • 한국의류학회지
    • /
    • 제34권1호
    • /
    • pp.14-26
    • /
    • 2010
  • This study investigates the effectiveness of fashion coordination presentation formats when people buy apparel products online. This study conducted an online survey with 595 females who shopped online at the simulated website by a single apparel plan picture (n=189), coordination plane picture (n=187), and 3-D coordination image (n=216). For data analysis, factor analysis, Cronbach's alpha, MANCOVA, ANOVA, Duncan test, correlation analysis, and chi-square are used. The results of this study are: First, the hedonic shopping value was significantly the highest when respondents shopped at a 3-D coordination image shopping mall, the next highest-scored presentation type was the coordination plane picture, and the case of presenting only the single apparel picture was significantly the lowest. The utilitarian shopping value and information shopping value were higher in the coordination plane picture and the 3-D coordination image shopping mall than the single apparel picture. Second, transactions satisfaction was high when respondents shopped at a 3-D coordination image, coordination plane image, and single apparel image in decreasing order.

디커플링 조건 및 폴리머 겔 적용에 따른 발파공 발파위력 영향에 관한 수치해석 연구 (Study on Blast Effects of Decoupling Condition and Polymer Gel Coupling in Single Blast Hole by Numerical Analysis)

  • 고영훈;정승원;양형식
    • 화약ㆍ발파
    • /
    • 제36권2호
    • /
    • pp.1-9
    • /
    • 2018
  • 폴리머 겔의 발파 효과를 평가하기 위해 AUTODYN을 이용한 단일 발파공 모델 시뮬레이션을 수행하였다. 발파공 내부 에멀젼 폭약과 공벽간의 채움재는 공기와 폴리머 겔을 적용하여 서로 결과를 비교하였으며, 디커플링 지수 1.0인 밀장전과 디커플링 지수 1.25, 1.56에 대해 각각 해석하였다. 폴리머 겔의 발파 효과 평가를 위한 기준은 밀장전 case를 기준으로 하였다. 해석 결과로서 석회석 모델의 파쇄 및 균열 발생에서 공기보다 폴리머 겔 적용의 경우가 높은 파쇄 정도를 나타냈고, 지정 게이지에서의 최고압력 또한 공기의 경우보다 폴리머 겔 적용이 높은 수치를 보였다.

바이오디젤 혼합연료를 적용한 커먼레일 디젤엔진에서 파일럿 분사에 따른 연소 및 배기 특성 (Effect of Pilot Injection on Combustion and Exhaust Emissions Characteristics in a Biodiesel Fueled Diesel Engine)

  • 정규수;이동곤;노현구;이창식
    • 한국연소학회지
    • /
    • 제16권4호
    • /
    • pp.1-7
    • /
    • 2011
  • The purpose of this study was to analyze the effect of pilot injection strategy on the combustion and emissions characteristics in a four cylinder common-rail direct injection diesel engine fueled with biodiesel(soybean oil) blend. The tested fuel was mixed of 20% biodiesel and 80% ULSD(Ultra low sulfur diesel) by volume ratio. The experiments were performed under two load conditions, and results were compared with those of single injection. The experimental results showed that the ignition delay of BD20 was shorter than compared to that of ULSD in the case of low load condition. Also, the fuel consumption of BD20 was more higher than that of ULSD. Fuel consumption by applied pilot injection strategy were generally decreased compared with that of single injection. In the case of pilot injection, the exhaust emissions such as CO and HC emissions were decreased compared to the single injection.

단일시편방법의 CLS 시편 적용시 적층성이 미치는 영향 (Effects of Stacking Sequence on the Application of the Single Specimen Technique to CLS Specimen)

  • 이경엽;양준호
    • 대한기계학회논문집A
    • /
    • 제23권11호
    • /
    • pp.1952-1959
    • /
    • 1999
  • The work factor approach, so-called single specimen technique could be used to determine energy release rate from a single test record for unidirectional CLS specimen. In the present study, the work factor approach was extended to determine the mixed-mode fracture toughness of multi-directional graphite/epoxy laminated composites. Multi-directional CLS specimens were used for fracture tests. The stacking sequences used for the lap and the strap were $[90_2/0_2]_s/[0_4/90_4]_s$ and $[0/\pm45/0]_s/[0_2/\pm45_2/0_2]_2$, respectively. For both cases, the fracture toughness determined from the work factor approach was compared with that determined from the compliance method. It was found that both methods produced fracture toughness within a maximum 15% difference for each stacking sequence. The fractography analysis also showed that the fiber bridging occurred for$[0/\pm45/0]_s/[0_2/\pm45_2/0_2]_2$ case while it did not occur for $[90_2/0_2]_s/[0_4/90_4]_s$ case.

카드뮴 및 납의 수여가 백서골성분에 미치는 영향 (Effect of Cadmium and Lead with Single or Mixed Admin stration on Rat Bones)

  • 김영환;박국환
    • 한국환경보건학회지
    • /
    • 제8권1호
    • /
    • pp.55-60
    • /
    • 1982
  • This study was carried out in order to clarify the combined effect of cadmium and lead on rat bones when exposed to single metal (1 mg cd/kg body weight) and cambined metals (1 mg cd + 4 mg pb/kg body weight). Seventy five mature rats of Sprague-Dawley species were divided into a control group and a treatment group that were administered by daily peritoneum injection for 7 to 9 weeds, and their body weights were measured every week. The results were summarized as follows 1. Body weight gains of the combined injection group and the single injection groups were lower than that of the control group. 2. In case of the combined injection group, the amount of cadmium accumulated in femur was more than that of the cadmium group. These amounts of cadmium accumulated showed an increasing trend. 3. The lead amount in bone tissue of the combined injection group presented also an increasing trend. In this case, the additive action of cadmium to the lead accumulation in bone tissue was conspicuous. 4. The amounts of calcium and phosphorus in femur showed clear a decreasing trend in the cadmium group and combined administration group. The ratio of calcium and phosphorus (ca/p) in the cadmium group was not different from that of the control group, but in the combined injection group the ratio was a little lower.

  • PDF

동축 반전 시스템의 공력측정 (Aerodynamic Force Measurement of Counter-Rotating System)

  • 김수연;최종욱;김성초
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2008년도 춘계학술대회논문집
    • /
    • pp.39-42
    • /
    • 2008
  • In the case of the general helicopter among rotorcraft, length of the rotor blade for thrust-generation is longer than that of fuselage and tail rotor is required in order to compensate moment of the fuselage. For those reasons, enough space for take-off and landing should be secured and an accessibility for building is low. Also, the accidents caused by tail rotor occur frequently. However, the case of counter-rotating has merits that tail rotor is unnecessary as well as length of the rotor blade can be shortened but has a weakness that the weight of body is increased. In the present study, aerodynamic force measurement on single rotor system equipped with NACA0012 airfoil, which has aspect ratio of 6 and chord length of 35.5 mm, was carried out. And measurement was conducted with blade which has a half size of the former blade by using single motor counter-rotating. Aerodynamic force measurement was acquired by using 6-component balances and coefficients of thrust and power were derived along the pitch angle varying from 0$^{\circ}$ to 90$^{\circ}$ with the increment of 10$^{\circ}$. Those aerodynamic force data will be utilized for the design and production of brand-new counter-rotating rotor blade system which has same thrust with single blade system and provides a good accessibility to building by reducing its blade length.

  • PDF

METREX 확산실험 자료를 이용한 INPUFF모델의 평가 (Evaluation of INPUFF Model Using METREX Tracer Diffusion Experiment Data)

  • 이종범;송은영;황윤성
    • 한국대기환경학회지
    • /
    • 제18권6호
    • /
    • pp.437-452
    • /
    • 2002
  • The Metropolitan Tracer Experiment (METREX) was performed over the Washington, D.C. area using two inert, non-deposition perfluorocarbon gases for over 1 year period (November 1983∼December 1984). Two perfluorocarbon gas tracers (PDCH, PMCH) were released simultaneously at intervals of every 36 hours for 6 hours, regardless of the meteorological conditions in metropolitan area. Samples were collected continuously for 8 hours at a central downtown and two adjacent suburban locations. Monthly air samples were collected at 93 sites across the whole region (at urban, suburban, and rural locations). The purpose of this study is to simulate INPUFF and ISCST model using METREX data, and to compare calculated and observed concentrations. In the case of INPUFF simulation, two meteorological input data were used. One is result data from wind field model which was calculated by diagnostic wind model (DWM), the other is meteorological data observed at single station. Here, three kinds of model calculation were performed during April and July 1984; they include (1) INPUFF model using DWM data (2) INPUFF model using single meteorological data (3) ISCST model. The monthly average concentration data were used for statistic analysis and to draw their horizontal distribution patterns. Eight-hour-averaged concentration was used to describe movement of puff during the episode period. The results showed that the concentrations calculated by puff model (INPUFF) were better than plume model (ISCST). In the case of puff model (INPUFF), a model run using wind field data produced better results than that derived by single meteorological data.

일렬관군에서의 난류 후류특성에 관한 연구 (Turbulent Wake Flow around Tubes in Single Row Tube Banks)

  • 조석호;부정숙
    • 대한기계학회논문집
    • /
    • 제13권5호
    • /
    • pp.1023-1031
    • /
    • 1989
  • 본 연구에서는 격자관군(in-line tube banks)과 엇갈림관군(staggered tube banks)에서의 유동특성을 해명하기 위한 기초로서, 일렬관군에 대해 유동특성을 통계적으로 조사한다. 이를 위해, 먼저 유동의 가시화와 관의 표면압력 측정실험이 행해진다. 또한, 통계적 기법의 도입을 통하여 관 주위의 평균속도, 난류강도, 파워 스펙트럼 밀도함수, 스트로홀수(strouhal number), 자기상관계수, 활률 밀도함수 등의 측정이 수행된다.

Determinants of Foreign Direct Investment: Evidence from Provincial Level Data in Indonesia

  • MEIVITAWANLI, Bryna
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제8권5호
    • /
    • pp.53-60
    • /
    • 2021
  • Foreign direct investment (FDI) is especially important for developing countries. This study investigates the determinants of FDI in the case of Indonesia. Most empirical researches in this field used time series data of a single country or panel data of several countries. Although panel data analysis is more comprehensive, however results taken from cross-country analysis cannot be directly applied to any specific country in the dataset and therefore lacks practicality. In this research, panel data analysis of a single country is performed to overcome the aforementioned shortcomings. Five determinants of FDI are tested using panel data of 33 Indonesian provinces over 10-year period of time. Two methodologies are adopted, random/fixed effects model and Granger Causality. The results show that only market size significantly affects FDI when tested using both methodologies. Human capital and financial market development show significant result in one of the two methodologies. While, economic growth and infrastructure did not show any significant results at all. This research stresses the importance of comprehensive single country analysis since only one out of five commonly discussed determinants is applicable in the case of Indonesia. Governments should therefore carefully reconsider the use of cross-country analysis as a basis of their policy formulations.

울산시 1인가구의 가족가치관 및 돌봄노동에 대한 사례연구 (Family Values and Caring Work of Single-Person Households in Ulsan: A Case Study)

  • 권안나
    • 가족자원경영과 정책
    • /
    • 제27권2호
    • /
    • pp.35-47
    • /
    • 2023
  • 본 연구의 목적은 1인가구의 변화하는 가족가치관과 매일 일상 속에서 이뤄지는 돌봄노동에 주목하여, 가족의 변화나 역동성을 파악하고 이에 대응하기 위한 제도 및 정책적 과제를 제안하는 것이다. 연령·혼인상태를 고려하여 울산시에 거주하는 1인가구 11명을 선정하였으며, 1인가구의 전반적인 일상생활, 가족가치관, 가사노동 및 돌봄 특성을 분석하였다. 이에 따른 울산시 1인가구의 특성은 자신의 삶을 유지하고 살아감에 있어 '단순하지만 불안정함'이 공존하고 있었으며, 가족가치관은 다양성에 대한 인식과 실제의 격차를 보이는 양면적 특성을 보이고 있었다. 또한 가족생활을 함에 있어 '원가족 돌봄 및 관계', '경제적 요인' 등에 대한 어려움을 호소하고 있었으며, '이중가치체계'가 두드러지게 나타났다. 마지막으로 1인가구는 안정된 삶을 위해 전통적인 가족형성의 방법에만 국한하는 것이 아닌, 고립·고독감 해소 및 관계 회복을 위해 사회관계망을 형성해나가고 있는 것으로 나타났다. 이에 따라 '가족인식', '가족생활', '가족 및 사회적 관계'의 각 영역에서 변화가 도모되었을 때 가족변화에 대응할 수 있을 것으로 보이며, 연구 결과에 기반한 정책과제를 도출하였다.