• Title/Summary/Keyword: Design Variables

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Evaluation of Vertical Vibration Performance of Tridimensional Hybrid Isolation System for Traffic Loads (교통하중에 대한 3차원 하이브리드 면진시스템의 수직 진동성능 평가)

  • Yonghun Lee;Sang-Hyun Lee;Moo-Won Hur
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.1
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    • pp.70-81
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    • 2024
  • In this study, Tridimensional Hybrid Isolation System(THIS) was proposed as a vibration isolator for traffic loads, combining vertical and horizontal isolation systems. Its efficacy in improving serviceability for vertical vibration was analytically evaluated. Firstly, for the analysis, the major vibration modes of the existing apartment were identified through eigenvalue analysis for the system and pulse response analysis for the bedroom slab using commercial structural analysis software. Subsequently, a 16-story model with horizontal, vertical and rotational degrees of freedom for each slab was numerically organized to represent the achieved modes. The dynamic analysis for the measured acceleration from an adjacent ground to high-speed railway was performed by state-space equations with the stiffness and damping ratio of THIS as variables. The result indicated that as the vertical period ratio increased, the threshold period ratio where the slab response started to be suppressed varied. Specifically, when the period ratio is greater than or equal to 5, the acceleration levels of all slabs decreased to approximately 70% or less compared to the non-isolated condition. On the other hand, it was ascertained that the influence of damping ratios on the response control of THIS is inconsequential in the analysis. Finally, the improvement in vertical vibration performance of THIS was evaluated according to design guidelines for floor vibration of AIJ, SCI and AISC. It was confirmed that, after the application of THIS, the residential performance criteria were met, whereas the non-isolated structure failed to satisfy them.

Research Trends in Neonatal Simulation Practice Education of Nursing Students (간호대학생의 신생아 시뮬레이션 실습교육 연구동향(2011년~2023년))

  • Sung Hee Choi;Sang Hee Kim;Sun Hui Kim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.2
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    • pp.215-224
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    • 2024
  • The purpose of this study was to examine research trends related to neonatal simulation practice education of domestic nursing students. It was a descriptive research study. For literature collection, a total of 17 journals were selected as a result of a search using ('Newborn Simulation') AND ('Nursing Student' OR 'Nursing College Student' OR 'Student Nurse') in 6 domestic electronic databases. The research results showed that it started with 7 journals from 2011 to 2015 and decreased slightly to 5 journals from 2016 to 2020 and 5 journals from 2021 to 2023. The research design was mostly quantitative with a total of 16 journals(94%). Among them, there were 15 intervention journals(88%), 1 descriptive research journals(6%), and 1 mixed method journals(6%). The key topics in simulation practice were high-risk newborns with 9 journals(52%), respiratory distress syndrome in neonatal intensive care units appeared with 3 journals(18%), neonatal care with 3 journals(18%), normal newborn care with 1 journal(6%), and neonatal emergency airway care with 1 journals(6%). The main outcome variables were clinical performance, accounting for 5 journals(19.2%), followed by practice satisfaction 3 journals(11.5%). clinical competency and practice satisfaction were found to have significant positive effects. In conclusion, various research methods are required, such as expansion of nursing students' neonatal simulation practice education, repeated research, and qualitative research.

Effects of Non-face-to-face Sleep Programs Combined with Aroma Necklaces on Sleep Quality, Sleepiness, Depression, and Stress in Insomnia with College Students (아로마 목걸이를 병용한 비대면 수면 프로그램이 불면증 대학생의 수면의 질, 주간졸림증, 우울 및 스트레스에 미치는 효과)

  • Yeong-Ju Shin;Jaegap Ko;Minseo Kim;Yuna Kim;Ui-Hyeon Kim;Jiho Kim;Boseong Kim;Ju Namgung;Hanbin Yoon;Sang-Gyu Hyun;Eun-Kyoung Han
    • Journal of the Korean Applied Science and Technology
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    • v.41 no.1
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    • pp.96-106
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    • 2024
  • This study aimed to examine the effects of non-face-to-face sleep program combined with aroma necklace on quality of sleep, daytime sleepiness, depression, and stress in insomnia with college students. A nonequivalent control group pre-post test design was used. The experimental group(n=21) underwent non-face-to-face sleep program combined with aroma-necklace while the control group(n=21) received a sleep booklet. Sleep quality, daytime sleepiness, depression, and stress were measured to identify the effectiveness of the program. Data were analyzed using descriptive statistics, Fisher's exact test, χ2-test, and independent t-test with the SPSS 24.0 program. In the homogeneity test of the general characteristics and study outcome variables there were no significant differences between the two groups. Significant group differences were found in sleep quality (t=-5.87, p<.001), daytime sleepiness(t=-4.28, p<.001), and depression(t=-4.40, p<.001). No differences were found in the stress. Non-face-to-face sleep improvement program combined with an aroma-necklace was effective in improving insomnia in college students. Nurses can contribute to improving sleep and depression by applying this program to college students experienced insomnia living in various environments.

Numerical and experimental investigations on the aerodynamic and aeroacoustic performance of the blade winglet tip shape of the axial-flow fan (축류팬 날개 끝 윙렛 형상의 적용 유무에 따른 공기역학적 성능 및 유동 소음에 관한 수치적/실험적 연구)

  • Seo-Yoon Ryu;Cheolung Cheong;Jong Wook Kim;Byeong Il Park
    • The Journal of the Acoustical Society of Korea
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    • v.43 no.1
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    • pp.103-111
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    • 2024
  • Axial-flow fans are used to transport fluids in relatively low-pressure flow regimes, and a variety of design variables are employed. The tip geometry of an axial fan plays a dominant role in its flow and noise performance, and two of the most prominent flow phenomena are the tip vortex and the tip leakage vortex that occur at the tip of the blade. Various studies have been conducted to control these three-dimensional flow structures, and winglet geometries have been developed in the aircraft field to suppress wingtip vortices and increase efficiency. In this study, a numerical and experimental study was conducted to analyze the effect of winglet geometry applied to an axial fan blade for an air conditioner outdoor unit. The unsteady Reynolds-Averaged Navier-Stokes (RANS) equation and the FfocwsWilliams and Hawkings (FW-H) equation were numerically solved based on computational fluid dynamics techniques to analyze the three-dimensional flow structure and flow noise numerically, and the validity of the numerical method was verified by comparison with experimental results. The differences in the formation of tip vortex and tip leakage vortex depending on the winglet geometry were compared through a three-dimensional flow field, and the resulting aerodynamic performance was quantitatively compared. In addition, the effect of winglet geometry on flow noise was evaluated by numerically simulating noise based on the predicted flow field. A prototype of the target fan model was built, and flow and noise experiments were conducted to evaluate the actual performance quantitatively.

Factors Influencing Effects of Korea's Rural Life Improvement Program on Quality of Life of Rural Women (한국의 농촌 생활개선사업이 농촌여성의 삶의 질에 미치는 영향요인)

  • Bereket Roba Gamo;Yoon-Ji Choi;Jung-Shin Choi;Joo-Lee Son
    • Journal of Agricultural Extension & Community Development
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    • v.30 no.4
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    • pp.243-257
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    • 2023
  • Rural life improvement programs (RLIPs) have been implemented with a central goal of improving the quality of rural life and promoting rural welfare and cultural life. However, different factors may influence the effect of rural life improvement programs on rural communities or households. This study aimed to investigate the determinants of perceived effects of RLIPs on quality of life of rural women in South Korea. We used a mixed research design to generate data for this study. We collected survey data from 311 rural women who participated in the RLIPs and also conducted a focus group discussion. We analyzed the quantitative data using descriptive statistics and hierarchical regression to identify the variables that predicted effects of RLIPs on quality of life of rural women. Our study finds that age, type of residence in the community, leadership experience, level of education, community satisfaction and community participation influenced respondents' perceived effects of RLIPs. The results imply that the benefits of a development intervention could not be uniformly reaped by residents of a community.

A numerical analysis study on the effects of rock mass anisotropy on tunnel excavation (암반의 이방성이 터널 굴착에 미치는 영향에 대한 수치해석적 연구)

  • Ji-Seok Yun;Sang-Hyeok Shin;Han-Eol Kim;Han-Kyu Yoo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.26 no.4
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    • pp.327-344
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    • 2024
  • In general tunnel design and analysis, rock masses are often assumed to be isotropic. Under isotropic conditions, material properties are uniform in all directions, leading to a higher evaluation of tunnel stability. However, actual rock masses exhibit anisotropic characteristics due to discontinuities such as joints, bedding planes, and faults, which cause material properties to vary with direction. This anisotropy significantly affects the stress distribution during tunnel excavation, leading to non-uniform deformation and increased risk of damage. Therefore, thorough pre-analysis is essential. This study analyzes the displacement and stress changes occurring during tunnel excavation based on rock anisotropy. A three-dimensional numerical analysis was performed, selecting anisotropy index and dip angles as variables. The results showed that as the anisotropy index increased, the displacement in the tunnel increased, and stress concentration became more pronounced. The maximum displacement and shear stress were observed where the dip planes met the tunnel.

The Dual Mediating Role of Social Support and Self-esteem in the Relationship between Grit and Life Satisfaction among Chinese College Students (중국 대학생의 그릿과 삶의 만족의 관계에서 사회적 지지와 자아존중감의 이중 매개역할)

  • Ting Ting Ma;Jianan Li;Chang Seek Lee
    • Industry Promotion Research
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    • v.9 no.3
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    • pp.263-271
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    • 2024
  • The present study examines the dual mediating role of social support and self-esteem in the relationship between grit and life satisfaction among college students. Utilizing a cross-sectional design, we surveyed a sample of 326 undergraduates from one university in China by means of purposive sampling. The analyses were conducted using SPSS PC+ Win. ver. 25.0 and SPSS PROCESS macro ver. 4.2. Pearson's correlation analysis was performed to show the correlations among the variables, and Model 6 of the PROCESS macro for SPSS was used to verify dual mediation effects. First, correlation results indicated positive and significant correlations between grit, social support, self-esteem and life satisfaction. Second, the dual mediating role of social support and self-esteem in the relationship between grit and life satisfaction was proved. This study contributes to the literature by elucidating the psychological mechanisms through which grit operates to enhance life satisfaction. The results have implications for the development of interventions aimed at fostering grit and the enhancement of social support and self-esteem to improve life satisfaction. Suggestions for future studies were discussed in detail.

Evaluating the Impact of Walkability Environments on Leisure Walking Using Google Street View and Deep Learning - A Case Study of Yongsan District, Seoul - (구글 스트리트 뷰와 딥러닝을 활용한 보행 친화적 환경이 여가보행에 미치는 영향 평가 - 서울특별시 용산구를 대상으로 -)

  • Lee, Da-Yeon;Lee, Ji-Yun;Lee, Jae Ho
    • Journal of the Korean Institute of Landscape Architecture
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    • v.52 no.4
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    • pp.45-55
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    • 2024
  • This study aims to distinguish between utilitarian walking and leisure walking activities and analyze the correlation between these types of walking and the walking environment. To measure the walking environment, we utilized Google Street View (GSV) and employed semantic segmentation deep learning techniques to quantitatively assess urban walking environment elements as perceived by pedestrians. A survey was conducted to measure utilitarian walking, leisure walking, and perceived walking environment satisfaction, collecting valid responses from 192 participants. Using the survey data, we visualized utilitarian walking, leisure walking, and perceived walking environment satisfaction, and analyzed the correlation between these variables and the walkability scores. The results indicated that leisure walking had a significant positive correlation with walkability (Pearson's r = 0.121, p-value = 0.012), while there was no significant correlation between utilitarian walking and walkability (Pearson's r = 0.093, p-value = 0.055). These findings suggest that people prioritize mobility efficiency over the walking environment for utilitarian walking, whereas the quality of the walking environment significantly influences the frequency of leisure walking. Based on these results, the study proposes specific strategies to improve the walking environment around residential areas to promote leisure walking. These strategies include creating vertical gardens or various forms of three-dimensional gardens on narrow walkways and improving sidewalk design. The findings of this study can contribute to promoting leisure walking by creating walk-friendly environments, ultimately enhancing urban sustainability and the quality of life for residents.

An Exploratory Study on the Effects of Relational Benefits and Brand Identity : mediating effect of brand identity (관계혜택과 브랜드 동일시의 역할에 관한 탐색적 연구: 브랜드 동일시의 매개역할을 중심으로)

  • Bang, Jounghae;Jung, Jiyeon;Lee, Eunhyung;Kang, Hyunmo
    • Asia Marketing Journal
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    • v.12 no.2
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    • pp.155-175
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    • 2010
  • Most of the service industries including finance and telecommunications have become matured and saturated. The competitions have become severe while the differences among brands become smaller. Therefore maintaining good relationships with customers has been critical for the service providers. In case of credit card and debit card, the similar patterns are shown. It is important for them to maintain good relationships with customers, and therefore, they have used marketing program which provides customized services to customers and utilizes the membership programs. Not only do they build and maintain good relationships, but also highlight their brands from the emotional aspects. For example, KB Card or Hyundai Card uses well-known designers' works for their credit card design. As well, they differentiate the designs of credit cards to stress on their brand personalities. BC Card introduced the credit card with perfume that a customer would like. Even though the credit card is small and not shown to public easily, it becomes more important for those companies to touch the customers' feelings with the brand personalities and their images. This is partly because of changes in consumers' lifestyles. Y-generations becomes highly likely to express themselves in many different ways and more emotional than X-generations. For the Y-generations, therefore, even credit cards in the wallet should be personalized and well-designed. In line with it, credit cards with good design can be seen as an example of brand identity, where different design for each customer can be used to recognize the membership groups that customers want to belong. On the other hand, these credit card companies offer the special treatment benefits for those customers who are heavy users for the cards. For example, those customers who love sports will receive some special discounts when they use their credit cards for sports related products. Therefore this study attempted to explore the relationships between relational benefits, brand identification and loyalty. It has been well known that relational benefits and brand identification lead to loyalty independently from many other studies, but there has been few study to review all the three variables all together in a research model. Furthermore, as reviewed above, in the card industry, many companies attempt to associate the brand image with their products to fit their customers' lifestyles while relational benefits are still playing an important role for their business. Therefore in our research model, relational benefits, brand identification, and loyalty are all included. We focus on the mediating effect of brand identification. From the relational benefits perspective, only special treatment benefit and confidence benefit are included. Social benefit is not applicable for this credit card industry because not many cases of face-to-face interaction can be found. From the brand identification perspective, personal brand identity and social brand identity are reviewed and included in the model. Overall, the research model emphasizes that the relationships between relational benefits and loyalty will be mediated by the effect of brand identification. The effects of relational benefits which are confidence benefit and special treatment benefits on loyalty will be realized when they fit to the personal brand identity and social brand identity. In the research model, therefore, the relationships between confidence benefit and social brand identity, and between confidence benefit and personal identity are hypothesized while the effects of special treatment benefit on social brand identity and personal brand identity are hypothesized. Loyalty, then, is hypothesized to have positive relationships with personal brand identity and social brand identity. In addition, confidence benefit among the relational benefits is expected to have a direct, positive relationship with loyalty because confidence benefit has been recognized as a critical factor for good relationships and satisfaction. Data were collected from college students who have been using either credit cards or debit cards. College students were regarded good subjects because they are in Y-generation cohorts and have tendency to express themselves more. Total sample size was two hundred three at the beginning, but after deleting those data with many missing values, one hundred ninety-seven data points were remained and used for the model testing. Measurement items were brought from the previous literatures and modified for this research. To test the reliability, using SPSS 14, chronbach's α was examined and all the values were from .874 to .928 exceeding over .7. Using AMOS 7.0, confirmatory factor analysis was conducted to investigate the measurement model. The measurement model was found good fit with χ2(67)=188.388 (p= .000), GFI=.886, AGFI=.821, CFI=.941, RMSEA=.096. Using AMOS 7.0, structural equation modeling has been used to analyze the research model. Overall, the research model fit were χ2(68)=188.670 (p= .000), GFI=.886, AGFI=,824 CFI=.942, RMSEA=.095 indicating good fit. In details, all the paths hypothesized in the research model were found significant except for the path from social brand identity to loyalty. Personal brand identity leads to loyalty while both confidence benefit and special treatment benefit have a positive relationships with personal and social identities. As well, confidence benefit has a direct positive effect on loyalty. The results indicates the followings. First, personal brand identity plays an important role for credit/debit card usage. Therefore even for the products which are not shown to public easy, design and emotional aspect can be important to fit the customers' lifestyles. Second, confidence benefit and special treatment benefit have a positive effects on personal brand identity. Therefore it will be needed for marketers to associate the special treatment and trust and confidence benefits with personal image, personality and personal identity. Third, this study found again the importance of confidence and trust. However interestingly enough, social brand identity was not found to be significantly related to loyalty. It can be explained that the main sample of this study consists of college students. Those strategies to facilitate social brand identity are focused on high social status groups while college students have not been established their status yet.

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Influence of Men's Clothing and Hairstyle on the Evaluation of Professionalism and Preference (남성 의복과 헤어스타일이 전문성 및 선호도 평가에 미치는 영향)

  • Kang, Seung-Hee;Lee, Myoung-Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.6
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    • pp.990-1001
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    • 2009
  • The purpose of this study was to investigate the effect of perceiver's gender, clothing, and hairstyle on the visual evaluation of men's professionalism and preference. A quasi-experimental method by questionnaire was used. The experimental design was a $2\times8\times2$ (perceiver's gender $\times$ clothing $\times$ hairstyle) factorial design by 3 independent variables. The stimuli were 16 photographs of a man in his twenties. The upper clothing of the man included tailored collar jackets in beige and dark blue colors, and jumpers and sweaters in beige, dark blue, and red colors. The lower clothing of the men included jean pants. Two types of the hairstyles included short hair and medium length hair. The subjects were 208 men and 223 women in Seoul, Korea. Wearing a beige sweater with jean pants was evaluated high in intellectual image, a red jumper was perceived low in intellectual image, and a beige tailored collar jacket was evaluated low in potent image. Men's short hairstyle was evaluated to be more professional than the medium length hair. Male perceivers liked short hair more than medium length hair, but female perceivers evaluated both hairstyles similarly. In the case of women, the preferences of tailored collared jacket and soutien collared jumper were similar, but jumper was preferred to jacket in the case of men. Male perceivers showed more positive feedback towards jean pants with soutien collared jumper than jeans with tailored collared jacket, which indicated that men showed more conservative attitude towards the outfit than women. The man who was wearing a jumper with short hair was evaluated positively and the man who was wearing a jacket with medium length hair was evaluated negatively when the attires were coordinated with jean pants. In conclusion, medium length hairstyle with a beige jacket and short hairstyle with a red sweater were evaluated as professional image; and the results indicated that clothing and hairstyle interact with each other and influence the evaluation of professionalism.