• Bulletin of the Korean Mathematical Society
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• v.45 no.1
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• pp.23-31
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• 2008

In this paper, we investigate nonoscillatory solutions of a class of higher order neutral nonlinear difference equations with positive and negative coefficients $\Delta^m(x(n)+p(n)x(\tau(n)))+f_1(n,x(\sigma_1(n)))-f_2(n,x(\sigma_2(n)))=0,\;n{\geq}n_0$. Some sufficient conditions for the existence of nonoscillatory solutions are obtained.

• Journal of applied mathematics & informatics
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• v.31 no.1_2
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• pp.199-209
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• 2013

In this paper, we study the oscillation problem of the following higher-order neutral differential equation with positive and negative coefficients and mixed arguments $$z^{(n)}(t)+q_1(t)|x(t-{\sigma}_1)|^{\alpha-1}x(t-{\sigma}_1)+q_2(t)|x(t-{\sigma}_2)|^{\beta-1}x(t-{\sigma}_2)=e(t)$$, where $t{\geq}t_0$, $z(t)=x(t)-p(t)x(t-{\tau})$ with $p(t)$ > 0, ${\beta}>1>{\alpha}>0$, ${\tau}$, ${\sigma}_1$ and ${\sigma}_2$ are real numbers. Without imposing any restriction on ${\tau}$, we establish several oscillation criteria for the above equation in two cases: (i) $q_1(t){\leq}0$, $q_2(t)>0$, ${\sigma}_1{\geq}0$ and ${\sigma}_2{\leq}{\tau}$; (ii) $q_1(t){\geq}0$, $q_2(t)<0$, ${\sigma}_1{\geq}{\tau}$ and ${\sigma}_2{\leq}0$. As an interesting application, our results can also be applied to the following higher-order differential equation with positive and negative coefficients and mixed arguments $$x^{(n)}(t)+q_1(t)|x(t-{\sigma}_1)|^{\alpha-1}x(t-{\sigma}_1)+q_2(t)|x(t-{\sigma}_2)|^{\beta-1}x(t-{\sigma}_2)=e(t)$$. Two numerical examples are also given to illustrate the main results.

• Kyungpook Mathematical Journal
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• v.47 no.1
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• pp.1-20
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• 2007

In this paper, oscillation and nonoscillation criteria are established for nonlinear neutral delay differential equations with several positive and negative coefficients $$[x(t)-R(t)x(t-r)]^{\prime}+\sum_{i=1}^{m}Pi(t)H_i(x(t-{\tau}_i))-\sum_{j=1}^{n}Q_j(t)H_j(x(t-{\sigma}_j))=0$$. Our criteria improve and extend many results known in the literature. In addition we prove that under appropriate hypotheses, if every solution of the associated linear equation with constant coefficients, $$y^{\prime}(t)+\sum_{i=1}^{m}(p_i-\sum_{k{\in}J_i}qk)y(t-{\tau}_i)=0$$, oscillates, then every solution of the nonlinear equation also oscillates.

• Fashion & Textile Research Journal
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• v.7 no.5
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• pp.509-518
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• 2005

In recent years retail competition has intensified, generally as a consequence of technologies, more sophisticated management practices and industry consolidation. An understanding of current customers' loyalty intentions and their determinants is an important basis for the identification of optimal retailer actions. The focus of this study is to examine the links between patronage intention and the effects of various antecedents of current customers' store loyalty intentions in fashion store. 340 female universities students living in Seoul were analyzed by utilizing multiple regressions to investigate the predictability of each of the 4 different sets of variables(consumer value, source of information, clothing benefits, importance of store attributes) on four patronage intentions of apparel shopping(discount store, speciality store, conventional market, Fashion shopping mall). Four factors were significant in predicting conventional market patronage intention. Brand had a negative coefficient, while price, social affiliation, store fashion service/promotion had positive coefficients. Fashion shopping mall were predicted by five factors:brand had a negative coefficient, while media, social affiliation, price, uniqueness had positive coefficients. For specialty store, four factors were significant: brand had a negative coefficient, while store fashion service/promotion, personal sources, uniqueness had positive coefficients. Four factors were significant in predicting discount store patronage intention :price, store fashion service/promotion, social affiliation, variety of price & product had positive coefficients. Despite the relatively low $r^2s$, all four variables appeared to have, to some degree, predictability of choosing among four different types of store for apparel shopping. Based on the results, patronage intention profiles for four retail stores were developed. Marketing implications are discussed.

• Research in Community and Public Health Nursing
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• v.30 no.4
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• pp.571-580
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• 2019

Purpose: The purpose of this study is to examine the mediating effects of emotional venting via instant messaging (IM) and positive emotion in the relationship between negative emotion and depression. Methods: Online survey was conducted in Korea between 2 April and 7 April 2019. To obtain samples with representativeness, data were gathered by the professional research firm. A total of 250 Koreans were participated in this study. The collected data were analyzed using descriptive statistics, Pearson's correlation coefficients, and SPSS PROCESS macro to test the mediating effects. Results: This study analyzed the direct/indirect effects of negative emotion on emotional venting via IM, in the relationship between positive emotion and depression. Negative emotion had indirect effects on depression through emotional venting via IM and positive emotion. Both emotional venting via IM and positive emotion had dual mediating effects in the influence of negative emotion on depression. Conclusion: These results suggest that it is important to manage negative emotion to prevent depression. Also, this study confirmed that emotional venting via IM is a powerful factor influencing emotional recovery.

• Journal of Bio-Environment Control
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• v.1 no.1
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• pp.28-36
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• 1992

The wind pressure distributions were analyzed to provide fundamental criteria for the structural design on e single-span arched house according to the wind directions through the wind tunnel experiment. In order to investigate the wind force distributions, the variation of the wind force coefficients, the mean wind force coefficients, the drag force coefficients and the lift force coefficients were estimated by using the experimental data. The results obtained are as follows: 1. When the wind direction was normal to the wall, the maximum positive wind pressure along the height of the wall occurred approximately at two-thirds of the wall height because of the effects of boundary layer flow. 2. When the wind direction was 30$^{\circ}$ to the wall, the maximum positive wind force occurred at the windward edge of the wall. When the wind direction was parallel to the wall, the maximum negative wind force occurred at the windward edge of the wall. 3. The maximum negative wind force along the width of the roof appeared around the width ratio, 0.4, and that along the length of the roof appeared around the length ratio, 0.5. 4. According to the results of the mean wind force coefficients analysis, the maximum negative wind force occurred on the roof at the wind direction of 30$^{\circ}$. 5. The wind forces at the wind direction of 30$^{\circ}$ instead of 0$^{\circ}$ are recommended in the structural design of supports for a house. 6. To prevent partial damage of a house structure by wind forces, the local wind forces should be considered to the structural design of a house.

• Korean Membrane Journal
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• v.7 no.1
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• pp.67-70
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• 2005

It is well known as the role of ion exchange membrane with functional group in membrane matrix. Recently, we were reported that the charged mosaic membrane within parallel array of negative and positive charge groups. In this study we are reported the properties for the various transport coefficients of metal and heavy metal ions across charged mosaic membrane based on non-equilibrium thermodynamics is not based on equilibrium state.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.05a
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• pp.120-122
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• 2003

In this study, an experiment was conducted in order to investigate the feasibility and effectiveness of and on-line subjective assessment (OLSA) system. The present study compared Galvanic Skin Response (GSR) with the OLSA by presenting 28 subjects in their 20s with pictures arousing either positive or negative sensibility. According to the correlation coefficients, changes in subjective sensibility caused by the positive visual stimulus were related more closely to GSR, from the positive visual stimulus, and changes in subjective sensibility caused by the negative visual stimulus were related more closely to GSR from the negative visual stimulus. In conclusion, the most remarkable characteristic of the present system is that it not only assesses the average sensibility when stimuli are presented, but also shows the changing strength of sensibility over time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2484-2498
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• 2017

Various types of social media make the people share their personal experience in different ways. In some social networking sites. Some users post their reviews, some users can support these reviews with comments, and some users just rate the reviews as kind of support or not. Unfortunately, there is rare explicit negative comments towards other reviews. This means if there is a link between two users, it must be positive link. Apparently, the negative link is invisible in these social network. Or in other word, the negative links are redundant to positive links. In this work, we first discuss the feature extraction from social media data and propose new method to compute the distance between each pair of comments or reviews on social media. Then we investigate whether we can predict negative links via regression analysis when only positive links are manifested from social media data. In particular, we provide a principled way to mathematically incorporate multi-facet data in a novel framework, Constructing Negative Links, CsNL to predict negative links for discovering the hidden information. Additionally, we investigate the ways of solution to general negative link predication problems with CsNL and its extension. Experiments are performed on real-world data and results show that negative links is predictable with multi-facet of social media data by the proposed framework CsNL. Essentially, high prediction accuracy suggests that negative links are redundant to positive links. Further experiments are performed to evaluate coefficients on different kernels. The results show that user generated content dominates the prediction performance of CsNL.

• Korean Journal of Poultry Science
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• v.50 no.1
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• pp.15-22
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• 2023

This study was to investigate the relationship between chick weight in the growing period and the laying performance of Korean native chicken (KNC) breeders. We measured the body weights of 1,384 KNC breeders at 1-140 days of age at two-week intervals. The age at first egg laying, hen-day and hen-housed egg production, and the egg weights were investigated. Correlation coefficients between the body weight and egg production traits were analyzed. The results showed that the correlation coefficients between body weight and age at first egg laying were significantly positive before 4 weeks, but negative after 8 weeks of age. The correlation coefficients between body weight and egg production rate were estimated to be negative before 8 weeks and positive after 12 weeks of age. Coefficients of hen-day and hen-housed egg production were similar. There was little correlation between body weight and egg weight at 32 weeks of age, whereas a low positive correlation was with egg weight at 50 weeks. In conclusion, there was little correlation between body weight and laying performance before 8 weeks of age, whereas a significant positive correlation was with body weight after 12 weeks. The results suggest that as the chick's weight increases in the late growing stage, sexual maturity is faster, the egg production rate is higher, and the egg weight increases. Therefore, the weight management of KNC female breeders is very important in the late growing stage, and the body weight of chicks must be maintained above the standard weight.