• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.2
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• pp.132-147
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• 2008

So far ubiquitous service (u-service) priority has seldom been empirically examined based on the customer's view. It is usual to prioritize the relative importance of u-service variables by the supplier's intuition and a few specialist's experienced knowledge. Such approaches have the disadvantage that they provide only limited empirical information on the field practices in relation to u-service since customer demand of u-service is poorly defined despite abundant interest in this problem. Therefore, the aim of this research was to develop u-service priority model in the context of multi-criteria framework integrating customer and supplier's view, using high technology acceptance theory as major controlling factors. An important question was how to measure or represent criteria that is important to u-service and should be included in a priority model. The selection criteria for the model variables were derived from high technology acceptance theory and AHP approach through the analysis of frequency count, elimination of overlapping factors and brainstorming with specialists. Daegu showed top-rankings in transportation-aid service, guidance service for the eyesight disabled and u-telematics service. In contrast, disaster prevention service and industrial specialized town service ranked highly in the typical supplier's approach were not a dominant determining factor in the u-service priority. The model identified the fact that typical high priority service in terms of supplier's view did not necessarily accompany the important predictor for the u-service priority.

• Food Science and Preservation
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• v.12 no.4
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• pp.411-416
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• 2005

Vitamin U(S-methylmethionin) levels were affected by cultivars, portion and storage times in Kimchi made from Korean Chinese cabbages. From this study, the outward parts contained high levels of vitamin U in two cultivars of Winter Pride and 55 days. Vitamin U levels in Kimchi during storage were increased during fermentation at $4^{\circ}C$. Leaf parts were 1.1-5.2 times higher in vitamin U levels than midribs in both cultivars. The levels of vitamin U were shown highest in outward leaf parts of 55 days cultivars. Like vitamin U, free amino acid also showed much higher levels in leaves. Levels of amino acids showed similarly changing patterns at different parts and cultivars of Korean Chinese cabbages in Kimchi. Threonine, alanine and proline appeared relatively abundant amino acids in most parts of sample. Moreover, methionine as a precursor of vitamin U has been reported that leaf parts contained the higher levels than midrib parts. But methionine was shown most core leaf parts. Methionine as a precursor of vitamin U, may not play a role in an increase of vitamin U of Korean Chinese cabbages in Kimchi.

• Bulletin of the Korean Mathematical Society
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• v.52 no.3
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• pp.1007-1025
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• 2015

Let $\mathbb{N}_0$ be the set of non-negative integers, and let P(n, l) denote the set of all weak compositions of n with l parts, i.e., $P(n,l)=\{(x_1,x_2,{\cdots},x_l){\in}\mathbb{N}^l_0\;:\;x_1+x_2+{\cdots}+x_l=n\}$. For any element $u=(u_1,u_2,{\cdots},u_l){\in}P(n,l)$, denote its ith-coordinate by u(i), i.e., $u(i)=u_i$. A family $A{\subseteq}P(n,l)$ is said to be t-intersecting if ${\mid}\{i:u(i)=v(i)\}{\mid}{\geq}t$ for all $u,v{\epsilon}A$. A family $A{\subseteq}P(n,l)$ is said to be trivially t-intersecting if there is a t-set T of $[l]=\{1,2,{\cdots},l\}$ and elements $y_s{\in}\mathbb{N}_0(s{\in}T)$ such that $A=\{u{\in}P(n,l):u(j)=yj\;for\;all\;j{\in}T\}$. We prove that given any positive integers l, t with $l{\geq}2t+3$, there exists a constant $n_0(l,t)$ depending only on l and t, such that for all $n{\geq}n_0(l,t)$, if $A{\subseteq}P(n,l)$ is non-trivially t-intersecting, then $${\mid}A{\mid}{\leq}(^{n+l-t-l}_{l-t-1})-(^{n-1}_{l-t-1})+t$$. Moreover, equality holds if and only if there is a t-set T of [l] such that $$A=\bigcup_{s{\in}[l]{\backslash}T}\;A_s{\cup}\{q_i:i{\in}T\}$$, where $$A_s=\{u{\in}P(n,l):u(j)=0\;for\;all\;j{\in}T\;and\;u(s)=0\}$$ and $$q_i{\in}P(n,l)\;with\;q_i(j)=0\;fo\;all\;j{\in}[l]{\backslash}\{i\}\;and\;q_i(i)=n$$.

• Communications for Statistical Applications and Methods
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• v.19 no.3
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• pp.345-358
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• 2012

In a parametric sample selection model, the distribution assumption is critical to obtain consistent estimates. Conventionally, the normality assumption has been adopted for both error terms in selection and main equations of the model. The normality assumption, however, may excessively restrict the true underlying distribution of the model. This study introduces the $S_U$-normal distribution into the error distribution of a sample selection model. The $S_U$-normal distribution can accommodate a wide range of skewness and kurtosis compared to the normal distribution. It also includes the normal distribution as a limiting distribution. Moreover, the $S_U$-normal distribution can be easily extended to multivariate dimensions. We provide the log-likelihood function and expected value formula based on a bivariate $S_U$-normal distribution in a sample selection model. The results of simulations indicate the $S_U$-normal model outperforms the normal model for the consistency of estimators. As an empirical application, we provide the sample selection model for car ownership and a car expense relationship.

• Spatial Information Research
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• v.17 no.4
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• pp.405-416
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• 2009

According to the changes of the city's paradigm, the demand on u-City increases rapidly. u-City has been built at 54 areas in Korea (as of May 2009). One of the important determinants of success or failure in the increasing of u-City is how to provide u-Services. Most current u-Services are Sensor Network-based monitoring services to manage urban infrastructure. u-GIS is one of fundamental requirements to implement 'any time and any where' u-Service which covers the essential meaningful term "ubiquitous". Hence, in this paper, we 1) describe the definition of the spatial awareness, 2) discuss how to converge (Spatial Embedding) among different spatial data : topographic spatial data, sensor spatial data, and more, 3) bring forth an advanced form of u-Service, 4) analyze the state-of-the-art u-GIS techniques.

• Bulletin of the Korean Mathematical Society
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• v.53 no.4
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• pp.1157-1169
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• 2016

We find the distributional solutions of the Wilson's functional equations $$u{\circ}T+u{\circ}T^{\sigma}-2u{\otimes}v=0,\\u{\circ}T+u{\circ}T^{\sigma}-2v{\otimes}u=0,$$ where $u,v{\in}{\mathcal{D}}^{\prime}({\mathbb{R}}^n)$, the space of Schwartz distributions, T(x, y) = x + y, $T^{\sigma}(x,y)=x+{\sigma}y$, $x,y{\in}{\mathbb{R}}^n$, ${\sigma}$ an involution, and ${\circ}$, ${\otimes}$ are pullback and tensor product of distributions, respectively. As a consequence, we solve the $Erd{\ddot{o}}s$' problem for the Wilson's functional equations in the class of locally integrable functions. We also consider the Ulam-Hyers stability of the classical Wilson's functional equations $$f(x+y)+f(x+{\sigma}y)=2f(x)g(y),\\f(x+y)+f(x+{\sigma}y)=2g(x)f(y)$$ in the class of Lebesgue measurable functions.

• Food Industry
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• s.206
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• pp.26-41
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• 2008

Recently, Korea have experienced numbers of FTAs with other countries, including Chile, EFTA(European Free Trade Association), Singapore, ASEAN(Association of South-East Asian Nations), and U.S. In particular, FTA with U.S. are expected to cause huge impact on food markets as well as agricultural sector in Korea. Many researches have analyzed and discussed about the impact on agricultural sector after Korean-U.S. FTA, but very small number of studies focus on the impact of Korean-U.S. FTA on food markets. The purpose of the paper is to discuss the impact of Korea-U.S. FTA on Korean dairy market. For the numerical simulations, this paper focus on the impact on cheese and butter markets. The results of numerical analysis in the paper will be helpful for the future research, because few (maybe no) studies conduct the numerical analysis to measure the impact of Korea-U.S. FTA on Korean food market.

• Journal of the Korean Mathematical Society
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• v.60 no.3
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• pp.521-536
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• 2023

Let R be a commutative ring with identity and S a multiplicative subset of R. In this paper, we introduce and study the notions of u-S-pure u-S-exact sequences and uniformly S-absolutely pure modules which extend the classical notions of pure exact sequences and absolutely pure modules. And then we characterize uniformly S-von Neumann regular rings and uniformly S-Noetherian rings using uniformly S-absolutely pure modules.

• Strategy21
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• s.42
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• pp.224-257
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• 2017

As the Trump administration withdraws the Paris Climate Agreement and shows its antipathy toward free trade, the U.S.'s soft power is most likely to weaken and its behaviors could be perceived as acts to surrender the U.S. hegemonic leadership in the world stage. Hegemonic stability theory notes that the existence of a hegemonic power contributes to international stability in the sense that it provides international public goods. A lack of the U.S's leadership in international politics, however, could be recognized as its denial of a hegemonic status. Is it intentional or accidental? The U.S's denial of hegemonic roles is the byproduct of the Trump administration's "American First" policy, not the showcase of its intention to transit hegemony to others. What is noteworthy is that China targets a niche market of hegemony as the U.S. denies its roles as the international leader. Put it another way, China attempts to ride hegemony for free when the U.S. denies its hegemonic roles accidentally. Faced with a niche market of hegemony, China has begun to accelerate its national strategy to make "Chinese Dream" come true. To that end, China promised again to keep the Paris Climate Agreement and attempts to play more active its roles in Shanghai Cooperation Organization(SCO), Asia Infra Investment Bank(AIIB), and "One Belt, One Road". Despite all these efforts, the U.S. is most likely to withdraw its denial of hegemony any time soon. The U.S's resumption of Freedom of Navigation Operations(FONOPs) could be a precursor of the return to a hegemonic power's willingness. In this vein, it is noteworthy that the South China Sea serves as a quasi-war zone for hegemonic conflict.

• Journal of the Korean Mathematical Society
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• v.51 no.4
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• pp.853-866
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• 2014

Constacyclic codes of length $p^s$ over $R=\mathbb{F}_{p^m}+u\mathbb{F}_{p^m}+u^2\mathbb{F}_{p^m}$ are precisely the ideals of the ring $\frac{R[x]}{<x^{p^s}-1>}$. In this paper, we investigate constacyclic codes of length $p^s$ over R. The units of the ring R are of the forms ${\gamma}$, ${\alpha}+u{\beta}$, ${\alpha}+u{\beta}+u^2{\gamma}$ and ${\alpha}+u^2{\gamma}$, where ${\alpha}$, ${\beta}$ and ${\gamma}$ are nonzero elements of $\mathbb{F}_{p^m}$. We obtain the structures and Hamming distances of all (${\alpha}+u{\beta}$)-constacyclic codes and (${\alpha}+u{\beta}+u^2{\gamma}$)-constacyclic codes of length $p^s$ over R. Furthermore, we classify all cyclic codes of length $p^s$ over R, and by using the ring isomorphism we characterize ${\gamma}$-constacyclic codes of length $p^s$ over R.