• Title/Summary/Keyword: Limited Dependent Variable

Search Result 76, Processing Time 0.025 seconds

A Study on the Relationship between Library budget and Library Usage (도서관 예산과 도서관 이용과의 관계에 관한 연구 - 부산지역 공공도서관을 중심으로 -)

  • Kim, Sun Ae
    • Journal of the Korean BIBLIA Society for library and Information Science
    • /
    • v.27 no.2
    • /
    • pp.193-212
    • /
    • 2016
  • The purpose of this paper is to explain the necessity of secure budget in public libraries with regard to promoting library usage. It is namely to attempt to find out if there really is a connection between library funding and library usage. For this purpose, the relevant data of all the 31 public libraries in Busan were collected from the 2013 National library Statistics of Korea. To determine the connection between library funding and usage, two variables were selected, 'TFI (Total Funding Indicator) = $\sqrt{personnelcosts{\times}materialcosts}$' for independent variable and 'LU (Library Usage) = (visits per year) + (loans per year)/number of inhabitants' for dependent variable. The results showed that there is a clear relationship between TFI and LU and If more cost is spent on personal resources and material resources, the total usage of the public library also increase. The findings are limited due to the fact that the observation was focusing on public libraries in one community and the period of observation was one year in 2013.

Implementation of Mobile Digital Signage System on the Moving Vehicle (차량 탑재형 모바일 디지털 사이니지 구현)

  • Kim, Hee Dong;Kim, Cha Sung
    • Journal of Information Technology Services
    • /
    • v.14 no.4
    • /
    • pp.257-267
    • /
    • 2015
  • We propose a vehicle-mounted, location-aware mobile digital signage system that can be used for public transportation through mobile communication. This paper proposes the installations of the LED display panels at the backside of the bus., which display traffic information to cars behind the bus. Information to be displayed would include, but is not limited to, road information, public commercials and private commercials. We propose the system architecture and further implement the prototype of mobile digital signage system for demonstration. The system is based on the Client-Server system. Each bus has a client terminal which detects the current location by a GPS receiver and sends its location information to the server using mobile communication function. The terminal device receives advertisements and traffic information from the server and displays it to the large LCD or LED panel installed at the inside and outside of the bus. We use the Android smartphone as a client system, which inherently equipped with GPS and mobile communication function. GPS detects the location of bus and reports its geo-location data to the traffic information center server via a wireless communication network. On the server side, we developed a specially designed control server, where it communicates with the other traffic information center and updates and manages the databases contents being displayed by each position. The server contains location dependent variable information and returns selected information back to the vehicle in real time. Spatial database is used to process location based data. Server system periodically receives the real time traffic information from the road information center database. And it process the information by bus location and bus line number. In this paper, we propose a mobile digital signage service and explain the system implementation of this service.

Evaluation of Strain, Strain Rate and Temperature Dependent Flow Stress Model for Magnesium Alloy Sheets (마그네슘 합금 판재의 변형률, 변형률 속도 및 온도 환경을 고려한 유동응력 모델에 대한 연구)

  • Song, W.J.;Heo, S.C.;Ku, T.W.;Kang, B.S.;Kim, J.
    • Transactions of Materials Processing
    • /
    • v.20 no.3
    • /
    • pp.229-235
    • /
    • 2011
  • The formability of magnesium alloy sheets at room temperature is generally low because of the inherently limited number of slip systems, but higher at temperatures over $150^{\circ}C$. Therefore, prior to the practical application of these materials, the forming limits should be evaluated as a function of the temperature and strain rate. This can be achieved experimentally by performing a series of tests or analytically by deriving the corresponding modeling approaches. However, before the formability analysis can be conducted, a model of flow stress, which includes the effects of strain, strain rate and temperature, should be carefully identified. In this paper, such procedure is carried out for Mg alloy AZ31 and the concept of flow stress surface is proposed. Experimental flow stresses at four temperature levels ($150^{\circ}C$, $200^{\circ}C$, $250^{\circ}C$, $300^{\circ}C$) each with the pre-assigned strain rate levels of $0.01s^{-1}$, $0.1s^{-1}$ and $1.0s^{-1}$ are collected in order to establish the relationships between these variables. The temperature-compensated strain rate parameter which combines, in a single variable, the effects of temperature and strain rate, is introduced to capture these relationships in a compact manner. This study shows that the proposed concept of flow stress surface is practically relevant for the evaluation of temperature and strain dependent formability.

An Equivalent Multi-Phase Similitude Law for Pseudodynamic Test on Small-scale RC Models : Verification Tests (RC 축소모형의 유사동적실험을 위한 Equivalent Multi-Phase Similitude Law : 검증실험)

  • Kim, Nam-Sik;Lee, Ji-Ho;Chang, Sung-Pil
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.8 no.5 s.39
    • /
    • pp.35-43
    • /
    • 2004
  • Small-scale models have been frequently used for seismic performance tests because of limited testing facilities and economic reasons. However, there are not enough studies on similitude law for analogizing prototype structures accurately with small-scale models, although conventional similitude law based on geometry is not well consistent in the inelastic seismic behavior. When fabricating prototype and small-scale model of reinforced concrete structures by using the same material, added mass is demanded from a volumetric change and scale factor could be limited due to aggregate size. Therefore, it is desirable that different material is used for small-scale models. Thus, a modified similitude law could be derived depending on geometric scale factor, equivalent modulus ratio and ultimate strain ratio. In this study, compressive strength tests are conducted to analyze the equivalent modulus ratio of micro-concrete to normal-concrete. Then, equivalent modulus ratios are divided into multi-phase damage levels, which are basically dependent on ultimate strain level. Therefore, an algorithm adaptable to the pseudodynamic test, considering equivalent multi-phase similitude law based on seismic damage levels, is developed. Test specimens, consisted of prototype structures and 1/5 scaled models as a reinforced concrete column, were designed and fabricated based on the equivalent modulus ratios already defined. Finally quasistatic and pseudodynamic tests on the specimens are carried out using constant and variable modulus ratios, and correlation between prototype and small-scale model is investigated based on their test results. It is confirmed that the equivalent multi-phase similitude law proposed in this study could be suitable for seismic performance tests on small-scale models.

Predicting Peer Rejection of Middle-school Students with Ordered Probit Analysis (중학생 또래따돌림('왕따')의 예측요인)

  • Lee, Sang-Gyun
    • Korean Journal of Social Welfare
    • /
    • v.37
    • /
    • pp.357-379
    • /
    • 1999
  • In recent years, the subject of peer rejection in school settings has received increased attention in the massmedia and counseling literature. This study focused on the effect of individual and environmental factors on peer rejection. Dependent variable was the number of perpetrating peer rejection and independent variables were psychological, behavioral, familial factors, exposure of peer rejection and perception about school policies. Ordered Probit model was employed because of the nature of limited dependent variable. The data were collected from 714 middle-school student in Seoul. Major findings were as follows. First of all, the adolescents who has aggression and problematic behaviors in school were more likely to participate in peer rejection. Second, negative parent-children relationships and the family structure didn't have significant effects on peer rejection. And there were not a significant effect of attitude toward academic value and academic achievement on peer rejection. Third, environmental risk factors such as negative peer relationship and the exposure to rejection had a significant increasing effect on peer rejection. But consistent school policies didn't have a significant effect. In conclusion, this study confirmed that peer rejection in school settings was affected by school environment such as negative-peer relationship, and exposure to rejection. Therefore, comprehesive and systematic intervention programs should be required to ensure that all the pupils at school have a right to learn in a safe and fear-free environment.

  • PDF

The Effect of Blood Nutrient Index on Depression (성인 여성의 혈액 영양소 지표가 우울지표에 미치는 영향)

  • Noh, Hyun Sun;Kim, Moon Ju
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.2
    • /
    • pp.248-261
    • /
    • 2021
  • The purpose of this study is that the blood nutrient indicator in adult women, is the depressive indicator. This study recruited 77 pre-menopausal women, and excluding missing values, 53 (mean age 44.2±6.5 years) blood indexes were statistically confirmed and then analyzed the effect of indexes on the Beck Depression Inventory. The Beck's Depression Inventory(BDI)'s average of the study subjects was 7.6±7.2, and most of the depression symptoms were within the normal range. Only two women were very serious and other two women were serious state. As a result of this study, 21 questions of BDI was classified into 5 sub-factors. Of these, 2 factors were considered physical depression, 1 factor was mood depression, 1 factor was cognitive depression, and 1 factor undecided. As a result of the correlation analysis, triglyceride, LDL(low density lipoprotein) cholesterol and potassium showed statistically significant positive relationship with depressive factors. On the other hand, HDL(high density lipoprotein) cholesterol, sodium and chloride ions showed negative relationship with depressive factors. When multiple regression analysis was performed. Considering the depression factors was dependent variable, and triglyceride, cholesterol, blood sugar, and ketone bodies was considered as independent variables. HDL(high density lipoprotein) cholesterol had a statistically significant negative effect on the depression factor 3. Considering the depression factors was dependent variable, and minerals were considered as independent variables. Potassium had a positive effect, and chloride ions had a negative effect on the depressive factor 3. This study was limited to 77 pre-menopausal women. In the future, post-menopausal women, men, and clinical neurological disorders group will be possible.

A Study on the Effects of Perceived Value on Customer Satisfaction, and Repurchase Intention among Traditional Markets Users in KOREA (지각된 가치가 고객만족과 재구매 의도에 미치는 영향에 관한 연구 : 전통시장 이용 고객을 중심으로)

  • Cho, Joon-Sang
    • Journal of Distribution Science
    • /
    • v.11 no.10
    • /
    • pp.93-105
    • /
    • 2013
  • Purpose - This empirical analysis determines the structured causal relations between perceived value, customer satisfaction, and repurchase intention among users of traditional markets. The results of this analysis would help merchants and market operators indevisingan appropriate strategy to successfully manage traditional markets. Research design, data, methodology - The perceived value model of traditional markets includes functional value (price), functional value (quality), emotional value, and social value. In this study, the perceived value of traditional markets is considered as an independent variable, while customer satisfaction and repurchase intention are shown as the dependent variables, where customer satisfaction is also considered as the mediating variable. The study aims to ascertain the extent of influence of the perceived value of traditional markets on customer satisfaction and repurchase intention. We use regression analysis to verify the effects. The measurement items were already deemed as reliable and valid in the previous study, but for this purpose, we made some modifications. We distributed questionnaires to 300 consumers on a national scale, and finally used 241 consumer responses among these as a sample. We analyzed the data using the SPSS 21.0 statistical program. Results - We obtained the following results. First, the order of perceived value dimensions of traditional markets that positively impact customer satisfaction is functional value (price), social value, emotional value, and functional value (quality). Second, the perceived value sometimes directly affects repurchase intention; its effect is typically strong with customer satisfaction as a parameter. The order of perceived value dimensions that positively impact repurchase intention is social value, functional value (price), emotional value, and functional value (quality). Third, the perceived value significantly influences repurchase intention, with customer satisfaction as the mediating variable. Conclusions - We should recognize the importance of perceived value in retail distribution markets, such as traditional markets. Moreover, we need to develop strategies to improve the perceived value. The practical implications of the study are as follows. First, with regards to functional value (quality; price) dimensions, we should have an appropriate assortment of high quality products that are reasonably priced. In addition, customers are satisfied with the friendly service, discounts, and other benefits provided by the merchants. Second, in terms of emotional value dimension, we need to develop differentiated events that provide fun and emotional experience to the customers. Third, in the context of social values dimension, we should strive to positively influence society to enhance social image through activities such as social services and contribution to community development. On the basis of these results, we present the implications, limitations, and future directions for the research. One of the policy implications of the study is that merchants of traditional markets must actively select customers and develop customer value. However, this study is limited in the fact that the population used for data collection is not fully representative, as the survey only covered some specific areas. Moreover, future studies could also benefit with additional research using moderating variables.

The Relationship between Wine-Selection Attributes and Consumer Satisfaction (와인 소비자의 선택 속성의 만족도에 관한 연구)

  • Bang, Jin-Sik;Choi, Tae-Ho;Jun, Jin-Hwa
    • Culinary science and hospitality research
    • /
    • v.12 no.2 s.29
    • /
    • pp.88-105
    • /
    • 2006
  • Entering into the new millennium, the Korean wine market has recorded the highest growth rate among the domestic alcoholic beverage market and been recognized as a rapidly emerging market with further escalation potential. Responding to the current drastic escalation of Korean wine market in terms of its volume, the present study scrutinizes the considerable wine-selection attributes that are related to individual wine consumer‘s characteristics including demographic variables. These attributes are also expected to be precursors of wine consumers‘ satisfaction. ANOVA results suggest that each demographical variable-gender, age, income level, and the frequency of wine consumption-pertains to specific wine-selection attribute(s). Likewise, wine consumers‘ characteristics are also associated with those attributes. As wine consumers are experienced, they rely less on information; rather, their selections tend to be dependent upon quality, value, contexts, and preferences. The subsequent multiple-regression investigating the relationship between wine-selection attributes and satisfaction signifies that quality, contexts, and preference attributes are the substantial antecedents of wine consumers‘ satisfaction. When consumers purchase a wine, "information on purchase" was the most important criterion for the Newcomers and the Outsiders, while the Connoisseurs mainly depended on "marketability", "wine values" and "viticulture environment". "Preference" attributes influenced the Aspirants the most in buying decision. The Newcomers and the Outsiders need more information before deciding to purchase as their wine knowledge was very limited. The Connoisseurs were likely to consider the quality as a more important factor than the price and it is necessary to develop high quality wine at a reasonable price in order to attract this group.

  • PDF

Phase-matched Harmonic Generation and Variable Slope Exponential Weighting for Virtual Bass System (위상 일치와 가변 지수 감쇠 가중치 부여 방법이 적용된 가상 저음 시스템)

  • Moon, Hyeongi;Park, Young-cheol;Whang, Young-soo
    • Journal of Broadcast Engineering
    • /
    • v.21 no.6
    • /
    • pp.889-898
    • /
    • 2016
  • Virtual Bass System (VBS) is widely used to extend the lower frequency limit of small loudspeakers, which generates harmonics of a fundamental frequency. The perceptual quality of the VBS is highly dependent on the harmonic weighting strategy. There have been several weighting methods, including exponential attenuation and timbre matching. However, it is essential to match phases between harmonics in the original signal and generate harmonics to precisely convey the weighting strategy. This paper shows the limitations of the previous harmonic weighting schemes and proposes a new harmonic weighting scheme. The proposed weighting scheme proposes phase matching between the original and generated harmonics and varies the slope of the attenuation weighting dynamically according to the missing fundamental frequency. Objective and subjective tests show that the proposed harmonic weighting scheme provides more natural and effective bass perception in a limited situation than the conventional schemes, which implies that the phase matching is essential for the high quality bass enhancement.

Simulation of nonstationary wind in one-spatial dimension with time-varying coherence by wavenumber-frequency spectrum and application to transmission line

  • Yang, Xiongjun;Lei, Ying;Liu, Lijun;Huang, Jinshan
    • Structural Engineering and Mechanics
    • /
    • v.75 no.4
    • /
    • pp.425-434
    • /
    • 2020
  • Practical non-synoptic fluctuating wind often exhibits nonstationary features and should be modeled as nonstationary random processes. Generally, the coherence function of the fluctuating wind field has time-varying characteristics. Some studies have shown that there is a big difference between the fluctuating wind field of the coherent function model with and without time variability. Therefore, it is of significance to simulate nonstationary fluctuating wind field with time-varying coherent function. However, current studies on the numerical simulation of nonstationary fluctuating wind field with time-varying coherence are very limited, and the proposed approaches are usually based on the traditional spectral representation method with low simulation efficiency. Especially, for the simulation of multi-variable wind field of large span structures such as transmission tower-line, not only the simulation is inefficient but also the matrix decomposition may have singularity problem. In this paper, it is proposed to conduct the numerical simulation of nonstationary fluctuating wind field in one-spatial dimension with time-varying coherence based on the wavenumber-frequency spectrum. The simulated multivariable nonstationary wind field with time-varying coherence is transformed into one-dimensional nonstationary random waves in the simulated spatial domain, and the simulation by wavenumber frequency spectrum is derived. So, the proposed simulation method can avoid the complicated Cholesky decomposition. Then, the proper orthogonal decomposition is employed to decompose the time-space dependent evolutionary power spectral density and the Fourier transform of time-varying coherent function, simultaneously, so that the two-dimensional Fast Fourier transform can be applied to further improve the simulation efficiency. Finally, the proposed method is applied to simulate the longitudinal nonstationary fluctuating wind velocity field along the transmission line to illustrate its performances.