• Honam Mathematical Journal
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• v.27 no.1
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• pp.115-129
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• 2005

In this paper, we give a digital graph-theoretical approach of the study of digital images with relation to a simplicial complex. Thus, a digital graph $G_k$ with some k-adjacency in ${\mathbb{Z}}^n$ can be recognized by the simplicial complex spanned by $G_k$. Moreover, we demonstrate that a graphically $(k_0,\;k_1)$-continuous map $f:G_{k_0}{\subset}{\mathbb{Z}}^{n_0}{\rightarrow}G_{k_1}{\subset}{\mathbb{Z}}^{n_1}$ can be converted into the simplicial map $S(f):S(G_{k_0}){\rightarrow}S(G_{k_1})$ with relation to combinatorial topology. Finally, if $G_{k_0}$ is not $(k_0,\;3^{n_0}-1)$-homotopy equivalent to $SC^{n_0,4}_{3^{n_0}-1}$, a graphically $(k_0,\;k_1)$-continuous map (respectively a graphically $(k_0,\;k_1)$-isomorphisim) $f:G_{k_0}{\subset}{\mathbb{Z}}^{n_0}{\rightarrow}G_{k_1}{\subset}{\mathbb{Z}^{n_1}$ induces the group homomorphism (respectively the group isomorphisim) $S(f)_*:{\pi}_1(S(G_{k_0}),\;v_0){\rightarrow}{\pi}_1(S(G_{k_1}),\;f(v_0))$ in algebraic topology.

• Sleep Medicine and Psychophysiology
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• v.24 no.2
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• pp.97-105
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• 2017

Objectives: To evaluate sleep characteristics and factors associated with sleep disturbance in schizophrenia patients with concurrent active psychotic symptoms and insomnia. Methods: Schizophrenia patients with insomnia and active psychotic symptoms (n = 63) were recruited from community-based mental rehabilitative facilities. Sleep scales such as the Korean version of the Insomnia Severity Index (ISI-K) and the Korean Version of the Pittsburgh Sleep Quality Index (PSQI-K) were evaluated and those with ISI-K >15 were included in the study. Psychotic, anxiety and depressive symptoms were rated with the Brief Psychotic Rating Scale (BPRS), the Korean Version of the Anxiety Sensitivity Index (K-ASI), and the Korean Version of the Beck Depression Inventory-I (K-BDI), respectively. Pearson correlation analyses were performed between the sociodemographic data, ISI-K and PSQI-K. Multiple linear regression analysis was conducted to investigate the factors which affected the ISI-K and PSQI-K. Results: The mean ISI-K and PSQI-K scores were $18.1{\pm}2.6$ and $12.0{\pm}2.2$, respectively. Pearson correlation analysis showed a negative correlation between age of onset and ISI-K score and positive correlations between BRPS and PSQI-K scores and between K-ASI and both ISI-K and PSQI-K scores. Multiple regression analyses for both ISI-K and PSQI-K with K-ASI, age of onset, and BPRS as covariates revealed K-ASI as the only significant remaining factor. Conclusion: Our study suggests that anxiety symptoms are associated with insomnia symptoms in schizophrenia patients regardless of depressive or psychotic symptoms.

• Korean Journal of Materials Research
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• v.13 no.8
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• pp.543-549
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• 2003

In order to investigate the thermoelectric properties of $Zn_{k}$ $In_2$$O_{ 3＋k}$ homologous compounds, the samples of $Zn_{k}$ /$In_2$$O_{3＋k}$ / (k = integer between 1 and 9) were prepared by calcining the mixed powders of ZnO and $In_2$$O_3$fellowed by sintering at 1823 K for 2 hours in air, and their electrical conductivities and Seebeck coefficients were measured as a function of temperature in the range of 500 K to 1150 K. X-ray diffraction analysis of the sintered samples clarified that single-phase specimens were obtained for $Zn_{k} /$In_2$$O_{3＋k}$ with k = 3, 4, 5, 7, 8, 9. Electrical conductivity of the $Zn_{k}$ $In_2$$O_{3＋k}$ / decreased with increasing temperature, and decreased with increasing k for k $\geq$ 3. The Seebeck coefficient was negative at all the temperatures for all compositions, confirming that $Zn_{k}$ $In_2$$O_{3＋k}$ / is an n-type semiconductor. Absolute values of the Seebeck coefficient increased linearly with increasing temperature and increased with increasing k for k $\geq$ 3. The temperature dependence of the Seebeck coefficient indicated that Z $n_{k}$I $n_2$ $O_{3＋k}$ could be treated as an extrinsic degenerate semiconductor. Figure-of-merits of Z $n_{k}$I $n_2$ $O_{3＋k}$ were evaluated from the measured electrical conductivity and Seebeck coefficient, and the reported thermal conductivity. Z $n_{7}$ I $n_2$ $O_{10}$ has the largest figure-of-merit over all the temperatures, and its highest value was $1.5{\times}$10$^{-4}$ $K^{-1}$ at 1145 K.5 K.

• Honam Mathematical Journal
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• v.44 no.1
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• pp.135-145
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• 2022

This paper aims to investigate characterizations on parameters k₁, k₂, k₃, k₄, k₅, l₁, l₂, l₃, and l₄ to find relation between the class of 𝓗(k, l, m, n, o) hypergeometric functions defined by $$5_F_4\[{\array{k_1,\;k_2,\;k_3,\;k_4,\;k_5\\l_1,\;l_2,\;l_3,\;l_4}}\;:\;z\]=\sum\limits_{n=2}^{\infty}\frac{(k_1)_n(k_2)_n(k_3)_n(k_4)_n(k_5)_n}{(l_1)_n(l_2)_n(l_3)_n(l_4)_n(1)_n}z^n$$. We need to find k, l, m and n that lead to the necessary and sufficient condition for the function zF([W]), G = z(2 - F([W])) and $H_1[W]=z^2{\frac{d}{dz}}(ln(z)-h(z))$ to be in 𝓢^*(2^-r), r is a positive integer in the open unit disc 𝒟 = {z : |z| < 1, z ∈ ℂ} with $$h(z)=\sum\limits_{n=0}^{\infty}\frac{(k)_n(l)_n(m)_n(n)_n(1+\frac{k}{2})_n}{(\frac{k}{2})_n(1+k-l)_n(1+k-m)_n(1+k-n)_nn(1)_n}z^n$$ and $$[W]=\[{\array{k,\;1+{\frac{k}{2}},\;l,\;m,\;n\\{\frac{k}{2}},\;1+k-l,\;1+k-m,\;1+k-n}}\;:\;z\]$$.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2086-2088
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• 2000

Key elements of in the development Electro-Thermal-Chemical propulsion (ETC) are high current pulse shaping, switching and storage bank device with high energy density 300kJ pulse power capacitor bank module for ETC application is designed and fabricated. The tested result are described.

• Korean Journal of Child Studies
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• v.36 no.1
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• pp.65-83
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• 2015

The purpose of this study was to validate the newly developed K-WPPSI-IV using other current IQ tests in common use in Korea such as the K-ABC and K-CTONI-2. Fifty three 2~7 year olds were tested with both the K-WPPSI-IV and K-ABC in a counterbalanced order. Simultaneous, cognitive, information processing as well as acquisition indices of K-ABC were moderately correlated with the total IQ of K-WPPSI-IV, ranging .44~.58. The results of these tests were comparable with US data: Correlations among WPPSI-IV & DAS-II subscales were .31~.67. The correlations among K-WPPSI-IV & K-CTONI-2 subscales in sixty two children ranged from .43~.49. WMI(Working memory index) as well as PSI(Processing speed index) of K-WPPSI showed low correlations with non-verbal IQ. These results indicated that nonverbal IQ does not test processing speed which in turn is very important in WMI & PSI Indices of K-WPPSI-IV. Further studies are needed to broaden the concurrent validities using K-WISC-IV or K-BSID-2. In addition, predictive as well as discriminate validity studies need to be conducted for better understanding of K-WPPSI-IV.

• Journal of the Korean Society of Food Culture
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• v.33 no.6
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• pp.501-511
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• 2018

Studies with various approaches are required for the globalization of Korean Food. The objectives of this study were i) how the preferences of foreign students residing in Korea on K-Wave, K-Drama, K-Pop and K-Friend affect their preference, satisfaction level and repurchase intention on Korean food, and ii) which of the factors have the strongest effects on their preference, satisfaction level and repurchase intention on Korean food. The results showed that the higher K-Wave, K-Drama, K-Pop and K-Friend preferences, the stronger effect on the preference, satisfaction level and repurchase intention on Korean food (p=0.0001). Among the factors for Korean food preference, the most critical one was K-Wave preference (p=0.0001), followed by K-Drama preference (p=0.0500). For the satisfaction level of Korean food, the most important factor among the four was K-Wave preference (p=0.0496), followed by K-Drama preference (p=0.0500). For the repurchase intention on Korean food, the most significant factor was the preference for K-Friend (p=0.0004), followed by K-Drama (p=0.0016) and K-Wave (p=0.0030). Based on these results, more efforts to invigorate the preferences for K-Wave and K-Drama, as well as various attempts to improve the preference for K-Friend are required for the globalization of Korean Food.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.165-170
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• 2024

'K-contents' is in the spotlight worldwide. As the prefix 'K' became popular, interest in K-food(Korean food) also increased. Various studies on K-contents are being conducted, but research on K-food is still very limited. References and articles about K-food are mainly limited to the overseas expansion, marketing status, and sales of domestic brands, and a few research papers deal with only cases of a specific brand's overseas expansion. This paper aims to analyze how K-food is represented in TV unscripted shows and TV series produced in Korea and what their effects are through empirical works. Among the unscripted shows based on food, they are estimated that the point of competitiveness as K contents deal with foreigners' Korean food experiences. Representative examples here are the way foreigners who visit Korea experience Korean food as part of their Korean culture experience, or the type of temporarily setting up a restaurant overseas to sell Korean food to local people. However, the problem with such shows are that it lacks long-term appeal because it is based on the 'Gukbbong(a slang term for 'extreme nationalism')' sentiment. The exposure of K-food in K-contents creates a tremendous advertising effect. It is judged that the current status and analysis of K-contents based on K-food can help establish the direction of future program production and the identity of K-food.

• Bulletin of the Korean Mathematical Society
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• v.42 no.3
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• pp.453-467
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• 2005

Let K be an algebraic number field. If k is the maximal cyclotomic subextension in K then the Schur K-group S(K) is obtained from the Schur k-group S(k) by scalar extension. In the paper we study projective Schur group PS(K) which is a generalization of Schur group, and prove that a projective Schur K-algebra is obtained by scalar extension of a projective Schur k-algebra where k is the maximal radical extension in K with mild condition.

• Bulletin of the Korean Space Science Society
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• 2005.04a
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• pp.27-27
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• 2005