• Title/Summary/Keyword: 상호작용 분석

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The Effect of Corporate Association on the Perceived Risk of the Product (소비자의 제품 지각 위험에 대한 기업연상과 효과: 지식과 관여의 조절적 역활을 중심으로)

  • Cho, Hyun-Chul;Kang, Suk-Hou;Kim, Jin-Yong
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.4
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    • pp.1-32
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    • 2008
  • Brown and Dacin (1997) have investigated the relationship between corporate associations and product evaluations. Their study focused on the effects of associations with a company's corporate ability (CA) and its corporate social responsibility (CSR) on consumers' product evaluations. Their study has found that both of CA and CSR influenced product evaluation but CA association has a stronger effect than CSR associations. Brown and Dacin (1997) have, however, claimed that there are few researches on how corporate association impacts product responses. Accordingly, some of researchers have found the variables to moderate or to mediate the relationship between the corporate association and the product responses. In particular, there has been existed a few of studies that tested the influence of the reputation on the product-relevant perceived risk, but the effects of two types of the corporate association on the product-relevant perceived risk were not identified so far. The primary goal of this article is to identify and empirically examine some variables to moderate the effects of CA association and CSR association on the perceived risk of the product. In this articles, we take the concept of the corporate associations that Brown and Dacin (1997) had proposed. CA association is those association related to the company's expertise in producing and delivering its outputs and CSR association reflected the organization's status and activities with respect to its perceived societal obligations. Also, this study defines the risk, which is the uncertainty or loss of the product and corporate that consumers have taken in a particular purchase decision or after having purchased. The risk is classified into product-relevant performance risk and financial risk. Performance risk is the possibility or the consequence of a product not functioning at some expected level and financial risk is the monetary loss one perceives to be incurring if a product does not function at some expected level. In relation to consumer's knowledge, expert consumers have much of the experiences or knowledge of the product in consumer position and novice consumers does not. The model tested in this article are shown in Figure 1. The model indicates that both of CA association and CSR association influence on performance risk and financial risk. In addition, the effects of CA and CSR are moderated by product category knowledge (product knowledge) and product category involvement (product involvement). In this study, the relationships between the corporate association and product-relevant perceived risk are hypothesized as the following form. For example, Hypothesis 1a($H_{1a}$) is represented that CA association has a positive influence on the performance risk of consumer. Also, the hypotheses that identified some variables to moderate the effects of two types of corporate association on the perceived risk of the product are laid down. One of the hypotheses of the interaction effect is Hypothesis 3a($H_{3a}$), it is described that consumer's knowledges of the product moderates the negative relationship between CA association and product-relevant performance risk. A field experiment was conducted in order to examine our model. The company tested was not real but imagined to meet the internal validity. Water purifiers were used for our study. Four scenarios have been developed and described as the imaginary company: Type A with both of superior CA and CSR, Type B with superior CSR and inferior CA, Type C with superior CA and inferior CSR, and Type D with both inferior of CA and CSR. The respondents of this study were classified into four groups. One type of four scenarios (Type A, B, C, or D) in its questionnaire was given to the respondent who filled out questions. Data were collected by means of a self-administered questionnaire to the respondents, chosen in convenience. A total of 300 respondents filled out the questionnaire but 207 were used for further analysis. Table 1 indicates that the scales in this study are reliable because the range of coefficients of Cronbach's $\alpha$ are from 0.85 to 0.92. The composite reliability is in the range of 0,85 to 0,92 and average variance extracted is in 0.72-0.98 range that is higher than the base level of 0.6. As shown in Table 2, the values for CFI, NNFI, root-mean-square error approximation (RMSEA), and standardized root-mean-square residual (SRMR) are acceptably close to the standards suggested by Hu and Bentler (1999):.95 for CFI and NNFI,.06 for RMSEA, and.08 for SRMR. We also tested discriminant validity provided by Fornell and Larcker (1981). As shown in Table 2, we found strong evidence for discriminant validity between each possible pair of latent constructs in all samples. Given that these batteries of overall goodness-of-fit indices were accurate and that the model was developed on theoretical bases, and given the high level of consistency across samples, this enables us to proceed the previously defined scales. We used the moderated hierarchical regression analysis to test the influence of the corporate association(CA and CSR associations) on product-relevant perceived risk(performance and financial risks) and to identify the variables moderating the relationship between the corporate association and product-relevant performance risk. In this study, dependent variables are performance and financial risk. CA and CSR associations are described the independent variables. The moderating variables are product category knowledge and product category involvement. The results are, as expected, found that CA association has statistically a significant influence on the perceived risk of the product, but CSR association does not. Product category knowledge and involvement moderate the relationship between the CA association and the perceived risk of the product. However, the effect of CSR association on the perceived risk of the product is not moderated by the consumers' knowledge and involvement. For this result, it is necessary for a corporate to inform its customers CA association more than CSR association so that they could be felt to be the reduction of the perceived risk. The important theoretical contribution of this research is the meanings that two types of corporate association that Brown and Dacin(1997), and Brown(1998) have proposed replicated the difference of the effects on product evaluation. According to Hunter(2001), it was an important affair to accomplish the validity of a particular study and we had to take about ten studies to deduce a strict study. Next, there is the contribution of the this study to find that the effects of corporate association on the perceived risk of the product are varied by the moderator variables. In particular, the moderating effect of knowledge on the relationship between corporate association and product-relevant perceived risk has not been tested in Korea. In the managerial implications of this research, we suggest the necessity to stress the ability that corporate manufactures the product well(CA association) than the accomplishment of corporate's social obligation(CSR association). This study suffers from various limitations that imply future research directions. The moderating effects of product category knowledge and involvement on the relationship between corporate association and perceived risk need to be replicated. Next, future research could explore whether the mediated effects of the perceived risk has the relationship between corporate association and consumer's product purchase. In addition, to ensure the external validity of the study will be needed to use realistic company, not artificial.

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Effects of TR and Consumer Readiness on SST Usage Motivation, Attitude and Intention (기술 준비도와 소비자 준비도가 Self Service Technology 사용동기와 태도 및 사용의도에 미치는 영향)

  • Shim, Hyeon Sook;Han, Sang Lin
    • Asia Marketing Journal
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    • v.14 no.1
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    • pp.25-51
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    • 2012
  • Researches about the relationship between SST(Self Service Technology) and TRI(Technology Readiness Index) have been carried out after TRI was developed by Parasuraman and his colleagues(2000). We hypothesize Consumer Readiness can also influence consumer's motivation, attitude, and intent to use SST. Currently, there has been no research on this subject. In this study, we investigated the relationship between TR, Consumer Readiness and SST Core Attitudinal Model which Dabholkar & Bagozzi(1994) proposed. The researchers also investigated moderating effects of consumer traits and situational factors to verify the acceptance of such forms of service delivery by all kinds of consumers and under different situational contexts. Self consciousness, the need for interaction with an employee, and the technology anxiety were used as consumer trait variables. Perceived waiting time and perceived crowding were used as situational variables. 380 questionnaires were distributed to a sample group of people in their 20's and 30's, and the data were analyzed with structural equation model using AMOS 18.0 program. All of Cronbach's alpha values representing reliabilities were satisfactory. The values of Composite Reliability(CR) and Average Variance Extracted(AVE) also showed the above criteria, thus providing evidence of convergent validity. To confirm discriminant validity among the constructs, confirmatory factor analysis and correlations among all the variables were examined. The results were satisfactory. The results of this study are summarized as follows. 1. Optimism and innovativeness of TR partially influenced the motivation to use SST. People who tend to be optimistic use SST because of ease of use and fun. The innovative however, usually use SST due to its performance. However, consumer readiness of role clarity, ability and self-efficacy influence all the components of motivation to use SST, ease of use, performance and fun. The relative effect of consumer readiness on the motivation to use SST was much stronger and more significant than that of TR. No other previous studies have examined the effects of Consumer Readiness on SST usage motivation, attitude and intention. It is academically meaningful that the researchers verified that Consumer Readiness is the important precedent construct influencing the self service technology core Attitudinal Model. Our findings suggest that marketers should consider fun and ease of use attributes to promote the use of self service technology. In addition, the SST usage frequency will rise rapidly when role clarity, ability, and self-efficacy which anybody can easily handle SST is assured. If the SST usage rate is increased, waiting times for customers could be decreased. Shorter waiting time could lead to higher customer satisfaction. It may also result in making a long-term profit owing to the reduced number of employees. Thus, presentation of using SST by employees or videos showing how to use it will promote the usage attitude and intent. 2. In SST core attitudinal model, performance and fun factors among SST usage motivation affected attitudes of using SST. The attitude of using SST highly influenced intent to use SST. This result is consistent with previous researches that dealt with the relationship between motivation, attitude and intention. Expectation of using SST could result in good performance just like the effect of ordering menu to service employees and to have fun since fun during its use could promote more SST usage rate. 3. In the relationship among motivation, attitude and intent in SST core attitudinal model, the moderating effect of consumer traits(self-consciousness, need for interaction with service employees and technology anxiety) and situational factors(perceived crowding and perceived waiting time) were tested. The results also supported the hypothesized moderating effects except perceived crowding. The highly self-conscious tended to form attitudes to use SST because of its fun compared to those who were less self-conscious because of its performance. People who had a high need for interaction with service employees tended to use SST for its performance. This result indicates that if ordering results are assured, SST is easily accessible to even consumers who have a high need for interaction with a service employee. When SST is easy to use, attitudes strengthen intent among people who had a high level of anxiety of technology. People who had low technology anxiety formed attitudes to use SST because of its performance. Service firms must ensure their self service technology is designed to be easy to use for those who have a high level of technology anxiety. Shorter perceived waiting times strengthened the attitude to use self service technology because of its fun. If the fun aspect is assured, people willing to use self service technology even perceive waiting time to be shorter than it actually is. Greater perceived waiting times form higher level of intent to use self service technology than those of shorter perceived waiting times. This implies that people view self service technology as a faster alternative to ordering service employees. The fun aspect of self service technology will attract a higher rate of usage for self service technology. 4. It has been proven that ease of use, performance and fun aspects are very important factors in motivation to form attitudes and intent to use self service technology regardless of the amount of perceived waiting time, self-consciousness, need for interaction with service employees, and technology anxiety. Service firms must consider these motivation aspects(ease of use, performance and fun)strongly in their promotion to use self service technology. Ease of use, assuring absolute performance compared to interaction with service employees', and adding a fun aspect will positively strengthen consumers' attitudes and intent to use self service technology. Summarizing the moderating effects, fun is the most valuable factor triggering SST usage attitude and intention. Therefore, designing self service technology to be fun will be the key to its success. This study focused on the touch screen self service technology in fast food restaurant. Although it has its limits due to the fact that it is hard to generalize the results to any other self service technology, the conceptual framework of this study can be applied to future research of any other service site.

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The Effect of Corporate SNS Marketing on User Behavior: Focusing on Facebook Fan Page Analytics (기업의 SNS 마케팅 활동이 이용자 행동에 미치는 영향: 페이스북 팬페이지 애널리틱스를 중심으로)

  • Jeon, Hyeong-Jun;Seo, Bong-Goon;Park, Do-Hyung
    • Journal of Intelligence and Information Systems
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    • v.26 no.1
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    • pp.75-95
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    • 2020
  • With the growth of social networks, various forms of SNS have emerged. Based on various motivations for use such as interactivity, information exchange, and entertainment, SNS users are also on the fast-growing trend. Facebook is the main SNS channel, and companies have started using Facebook pages as a public relations channel. To this end, in the early stages of operation, companies began to secure a number of fans, and as a result, the number of corporate Facebook fans has recently increased to as many as millions. from a corporate perspective, Facebook is attracting attention because it makes it easier for you to meet the customers you want. Facebook provides an efficient advertising platform based on the numerous data it has. Advertising targeting can be conducted using their demographic characteristics, behavior, or contact information. It is optimized for advertisements that can expose information to a desired target, so that results can be obtained more effectively. it rethink and communicate corporate brand image to customers through contents. The study was conducted through Facebook advertising data, and could be of great help to business people working in the online advertising industry. For this reason, the independent variables used in the research were selected based on the characteristics of the content that the actual business is concerned with. Recently, the company's Facebook page operation goal is to go beyond securing the number of fan pages, branding to promote its brand, and further aiming to communicate with major customers. the main figures for this assessment are Facebook's 'OK', 'Attachment', 'Share', and 'Number of Click' which are the dependent variables of this study. in order to measure the outcome of the target, the consumer's response is set as a key measurable key performance indicator (KPI), and a strategy is set and executed to achieve this. Here, KPI uses Facebook's ad numbers 'reach', 'exposure', 'like', 'share', 'comment', 'clicks', and 'CPC' depending on the situation. in order to achieve the corresponding figures, the consideration of content production must be prior, and in this study, the independent variables were organized by dividing into three considerations for content production into three. The effects of content material, content structure, and message styles on Facebook's user behavior were analyzed using regression analysis. Content materials are related to the content's difficulty, company relevance, and daily involvement. According to existing research, it was very important how the content would attract users' interest. Content could be divided into informative content and interesting content. Informational content is content related to the brand, and information exchange with users is important. Interesting content is defined as posts that are not related to brands related to interesting movies or anecdotes. Based on this, this study started with the assumption that the difficulty, company relevance, and daily involvement have an effect on the dependent variable. In addition, previous studies have found that content types affect Facebook user activity. I think it depends on the combination of photos and text used in the content. Based on this study, the actual photos were used and the hashtag and independent variables were also examined. Finally, we focused on the advertising message. In the previous studies, the effect of advertising messages on users was different depending on whether they were narrative or non-narrative, and furthermore, the influence on message intimacy was different. In this study, we conducted research on the behavior that Facebook users' behavior would be different depending on the language and formality. For dependent variables, 'OK' and 'Full Click Count' are set by every user's action on the content. In this study, we defined each independent variable in the existing study literature and analyzed the effect on the dependent variable, and found that 'good' factors such as 'self association', 'actual use', and 'hidden' are important. Could. Material difficulties', 'actual participation' and 'large scale * difficulties'. In addition, variables such as 'Self Connect', 'Actual Engagement' and 'Sexual Sexual Attention' have been shown to have a significant impact on 'Full Click'. It is expected that through research results, it is possible to contribute to the operation and production strategy of company Facebook operators and content creators by presenting a content strategy optimized for the purpose of the content. In this study, we defined each independent variable in the existing research literature and analyzed its effect on the dependent variable, and we could see that factors on 'good' were significant such as 'self-association', 'reality use', 'concernal material difficulty', 'real-life involvement' and 'massive*difficulty'. In addition, variables such as 'self-connection', 'real-life involvement' and 'formative*attention' were shown to have significant effects for 'full-click'. Through the research results, it is expected that by presenting an optimized content strategy for content purposes, it can contribute to the operation and production strategy of corporate Facebook operators and content producers.

Status of Maize Production and Distribution in South East Asia (동남아시아 옥수수 생산 및 유통현황)

  • Lee, Sang-Kyu;Song, Jun-Ho;Baek, Seong-Bum;Kwon, Young-Up;Lee, Byung-Moo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.60 no.3
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    • pp.318-332
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    • 2015
  • The maize production in South-eastern Asian countries showed a continuous increase with increasing poultry-livestock from the beginning of the 1990s to early 2010. Also the need for a new variety development of each contries was increased rapidly in the same period. Single-Cross hybrid varieties have been developed and supplied from 2001 instead of multi-cross maize varieties since 1992 in Indonesia. In Cambodia, CP group is mainly manufacturing feeds with most of the forage maize from farmers who are growing its seeds from the company. Cambodian main cultivars are varieties of multinational corporations such as DK8868 from Monsanto, NK6326, NK7328 from Syngenta and CP333 from CP group including local business company. Vietnam is the main maze importing country in South-Eastern Asia which had imported 13 times scale of amount compared to exports in average from 1990 to 2011. Vietnamese government has developed a range of varieties for improving their efficiency in production, such as the LVN-10 with political investments. Their production has been reached to 80% of the total. According to the 2012 MIFAFF (Ministry for Food, Agriculture, Forestry and Fisheries) data in Korea, domestic edible maize cultivation area was approximately 15,000ha. It showed 74,399 tons of production, 3.8% of food self-sufficiency in maize and around 0.9% of grain self-sufficiency rate. The consumption of grain is mostly rely on imports in Korea. To overcome the limit of the domestic seed market and increase maize self-sufficiency, the need to develop maze varieties for world-class is increasing at present through analyzing the market trend and prospect of the seed industry in South-eastern Asia.

Marine Environmental Characteristics in Western Coastal Waters of the South Sea of Korea (전남서부해역의 수질환경 특성)

  • Cho, Eun-Seob;Kim, Sang-Soo;Lee, Sang-Yong;Jeong, Hee-Dong;Kim, Sook-Yang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.3
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    • pp.187-203
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    • 2009
  • This study monitored marine environments in system coastal waters of the South Sea of Korea during the period of 2005-2007 and analyzed the data from environmental parameters and nutrients, which contributed to fluctuate marine environmental characteristics in aquaculture. On the basis of the fluctuation of temperature depending on seasons and sampling sites, too seasons of winter and summer showed a remarkable temperature gap of $5^{\circ}C$ compared with spring and autumn. Salinity in spring and summer approached 9 psu in Morkpo. Most of sampling sites showed COD below 2mg/L, indicating somewhat optimal environmental conditions. T-N and T-P also had desirable horizontal distributions all year round the concentration of SS was higher, but Chi. a was well-distributed horizontally except for Morkpo. Marone environmental parameters of surface water were similar to those of bottome water except for Morkpo. Most of sampling sites showed the ratio of N/P below 16, impling that nitrogen played an important role in growth of phytoplankton as a limiting factor. The relationship between Chi. a and nutrients was positive linear, whereas the relationship between Chi. a and COD were very strong positive. winder, Spring and Summer showed the strong relationship between Chi. a and COD. In the analysis of dendogram based on environmental parameters using SPSS ver. 10.0, the station 7 did not belong to other stations, and kept an independent place. The relationships of waters between Jindo, Wando and Heanam ware close, compared with other waters. Consequently, these regions except for Morkpo into which fresh water is introduced by the dike showed somewhat optimal environmental parameters and nutrients in year, and were assumed to maintain the desirable marine conditions for aquaculture.

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Validity of Long Form Assessment in Interactive Metronome® as a Measure of Children's Praxis (아동의 운동기능평가에 대한 Interactive Metronome® LFA의 타당도 연구)

  • Kim, Kyeong-Mi;Heo, Seo-Yoon;Kim, Mi-Su;Lee, Soo-Min
    • The Journal of Korean Academy of Sensory Integration
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    • v.13 no.1
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    • pp.13-22
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    • 2015
  • Objective : The aim of this study is to verify validity of Long Form Assessment, which is an Interactive Metronome $measure^{(R)}$(LFA-IM), as a measurement of praxis of children. Methods : The study was implemented from March 2015 to July 2015. Twenty-five children with Attention Deficit Hyperactivity Disorder (ADHD) and those without ADHD (age of 6~11) were selected from a local university hospital and community in Gyeoung-Nam province and Busan for this study. In order to examine discriminative validity of LFA-IM, Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2) was used to compare the difference of results with LFA-IM for both children with- and without ADHD. For concurrent validity, correlation between LFA-IM and BOT-2 was investigated using spearman correlation coefficients. Results : For the comparison between children with ADHD and children without ADHD, there were significant differences in the total scores of LFA-IM (p<.05). Regarding the concurrent validity, there was a strong negative correlation between the total scores of LFA-IM and BOT-2 (p<.05). In addition, there was high correlation between LFA-IM and BOT-2 for the area of hand control (rs=-.532), and high negative correlation for the area of fine-motor accuracy (rs=-.447), hand dexterity (rs=-.532), and balance control (rs=-.623) (p<.05). Conclusion : This study identified validities of LFA-IM as an assessment of praxis of children. The results showed that it is appropriate to evaluate praxis of children with the total score of LFA-IM and, thus, it is believed that LFA-IM has a potential clinical utility. However, there should be more researches with large number of subjects.

Dietary Behaviors, Body Satisfaction and Factors Affecting the Weight Control Interest According to Gender of Middle School Students in Wonju Area (원주지역 중학생들의 성별에 따른 식행동과 신체만족도 및 체중조절 관심도에 영향을 미치는 변인)

  • Kim, Bok-Ran;Kim, Yoon-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.9
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    • pp.1295-1304
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    • 2010
  • The purpose of this study was to investigate the BMI, dietary behaviors, body satisfaction and factors affecting the weight control interest according to gender of middle school students (195 boys and 251 girls) in Wonju area. The average height and weight of the boys were $164.8{\pm}8.3\;cm$ and $55.5{\pm}12.3\;kg$ respectively. Those of the girls were $158.8{\pm}5.0\;cm$ and $48.7{\pm}7.4\;kg$ respectively. The average body mass index (BMI) of the boys and girls was 20.3 and 19.3 respectively. In both boys and girls, 69.7% of them had regular meals and the main reason for skipping meals was insufficient time to eat due to oversleeping (33.6%). Most of the subjects consumed snacks more than once a day (95.5%). The dietary intake attitude score of the girls ($35.08{\pm}5.91$) was higher than that of the boys ($33.81{\pm}5.45$) (p<0.01). The eating disorders score of the girls ($12.92{\pm}6.22$) was higher than that of the boys ($10.70{\pm}9.82$) (p<0.01). Also, 87.2% of the subjects showed normal behavior and 12.8% of the subjects had eating disorders, but there was no significant difference according to gender. The body satisfaction score of the boys ($30.16{\pm}5.08$) was higher than that of the girls ($28.00{\pm}5.52$) (p<0.001). In general, body satisfaction score correlated positively with dietary intake attitude score, but correlated negatively with eating disorders score (p<0.05). Multiple regression analysis revealed that body satisfaction score was the most significant variable which affected the weight control interest. Therefore, development of the nutrition education program for adolescents will be effective not only for the improvement of dietary behaviors but also for the positive change in the misleading perception about the ideal body shape.

The Effect of Penalizing Wrong Answers Upon the Omission Response in the Computerized Modified Multiple-choice Testing (컴퓨터화 변형 선다형 시험 방식에서 감점제가 시험 점수와 반응 포기에 미치는 영향)

  • Song, Min Hae;Park, Jooyong
    • Korean Journal of Cognitive Science
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    • v.28 no.4
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    • pp.315-328
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    • 2017
  • Even though assessment using information and communication technology will most likely lead the future of educational assessment, there is little domestic research on this topic. Computerized assessment will not only cut costs but also measure students' performance in ways not possible before. In this context, this study introduces a tool which can overcome the problems of multiple choice tests, which are most widely used type of assessment in current Korean educational setting. Multiple-choice tests, in which options are presented with the questions, are efficient in that grading can be automated; however, they allow for students who don't know the answer, to find the correct answer from the options. Park(2005) has developed a modified multiple-choice testing system (CMMT) using the interactivity of computers, that presents questions first, and options later for a short time when the student requests for them. The present study was conducted to find out if penalizing wrong answers could lower the possibility of students choosing an answer among the options when they don't know the correct answer. 116 students were tested with the directions that they will be penalized for wrong answers, but not for no response. There were 4 experimental conditions: 2 conditions of high or low percentage of penalizing, each in traditional multiple-choice or CMMT format. The results were analyzed using a two-way ANOVA for the number of no response, the test score and self-report score. Analysis showed that the number of no response was significantly higher for the CMMT format and that test scores were significantly lower when the penalizing percentage was high. The possibility of applying CMMT format tests while penalizing wrong answers in actual testing settings was addressed. In addition, the need for further research in the cognitive sciences to develop computerized assessment tools, was discussed.

STUDY ON THE RELATIONSHIP BETWEEN THE ONTOGENETIC PROCESSES AND PSYCHOPATHOLOGY IN ATTENTION-DEFICIT HYPERACTIVITY DISORDER (주의력결핍 ${\cdot}$ 과잉운동장애의 Serotonin계의 개체발생적인 과정과 정신병리와의 상호관계에 관한 연구)

  • Jung, Yeoung;Shin, Sung-Woong;Whang, Joon-Won;Shin, Min-Sup;Cho, Soo-Churl
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.12 no.2
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    • pp.165-178
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    • 2001
  • In order to elucidate the biological etiology and the relationship between the ontogenesis of serotonin system and psychopathology in ADHD, plasma serotonin(5-hydroxytryptamine, 5-HT) and 5-hydroxyindoleacetic acid(5-HIAA) were measured and the correlation between the plasma levels of 5-HT and 5-HIAA and age were evaluated in 46 ADHD patients and 18 control subjects. The ADHD patients were composed of 16 combined type, 10 inattentive type, and 20 hyperactive-impulsive type and the control subjects were communication disorders. The results are summarized as follows:1) There was significant difference in plasma 5-HT levels among combined, inattentive and hyperactive-impulsive and control subjects(ANOVA F=4.33, df 3, 60, p<0.05), and post-hoc test using Scheffe method showed significant difference between the combined type and control group. But, post-hoc tests showed no significant differences between combined and inattentive, combined and hyperactive-impulsive, hyperactive-impulsive and inattentive, hyperactive-impulsive and control and inattentive and control groups. 2) There was no significant differences in plasma 5-HIAA levels among the combined, hyperactive- impulsive, inattentive and control groups(ANOVA F=2.08, df 3, 60, p>0.05). 3) Significant difference in 5-HT level was found between the whole ADHD group(N=46) and the control group(N=18)(T=3.10, df 62, p<0.05). But no significant difference in 5-HIAA level was found between the whole ADHD group and the control group(T=1.90, df 62, p>0.05). 4) Plasma 5-HT and 5-HIAA levels showed no significant correlation with TOVA findings(5-HT:omission pearson correlation 0.10, commision 0.23, reaction time 0.01, variability in attention 0.11, all p>0.05, 5-HIAA:omission 0.21, commision 0.15, reaction time 0.09, variability in attention 0.15, all p>0.05). 5) Plasma 5-HT and 5-HIAA levels showed no significant correlation with attention, hyperactivity and impulsivity based on DSM-IV criteria. 6) Plasma 5-HT and 5-HIAA levels showed no significant correlation with age both in ADHD and control group. These findings show that decreased plasma 5-HT level may play a role in the genesis of ADHD, but this finding has no significant correlation with the psychopathology of ADHD. And we could not find any significant differences in ontogenetic processes in 5-HT. Future studies should be focused on the drug effects, family history and prognosis based on the biochemical subtypes(high and low 5-HT group).

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Studies on Influence of Water-Proof Agents on the Properties of Mortar (방수제(防水劑)가 모르터의 제성질(諸性質)에 미치는 영향(影響)에 관(關)한 연구(硏究))

  • Kim, Seong Wan;Sung, Chan Yong;Kim, Sun Young
    • Korean Journal of Agricultural Science
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    • v.14 no.2
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    • pp.358-372
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    • 1987
  • This study was performed to obtain data which can be applied to use of water-proof mortars. The data was based on the properties of water-proof mortars depending upon various mixing ratios to compare those of cement mortar. The water-proof agents used were retard and accelerate type which are being used as mortar structures. The water-proof agents, mixing ratios of cement to fine aggregate were 1:1, 1:2, 1:3 and 1:4. The results obtained were summarised as follows; 1. The results of flow test, water-cement ratio was increased with the increasing of mixing ratio. 2. The permeability were increased in poorer mixing ratio and higher water pressure. 3. The bulk density was decreased with the increasing of mixing ratio, and compressive and tensile strength were increased with increasing of the bulk density. 4. At 1:1 mixing ratio, the highest strengths were showed and strengths were decreased with the increasing of mixing ratio. 5. The absorption rates were increased in- poorer mixing ratio 6. The correlation between W/C, permeability, bulk density, compressive strength and absorption rate were highly significant as a straight line, respectively.

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