• Communications of the Korean Mathematical Society
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• v.11 no.4
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• pp.997-1002
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• 1996

In this paper we extend the Zemanek's characterization of the Browder spectrum for a commuting n-tuple operators in $L(H)$ and show that if $T = (T_1, \cdots, T_n)$ is Browder then there exists an n-tuple $K = (K_1, \cdots, K_n)$ of compact operators and an invertible commuting n-tuple $(S_1, \cdots, S_n)$ for which $T = S + K$ and $S_i K_j = K_j S_i$ for all $1 \leq i, j \leq n$.

• Journal of the Chungcheong Mathematical Society
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• v.29 no.3
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• pp.429-442
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• 2016

In this paper we show that the solutions to the perturbed differential system $$y^{\prime}=f(t,y)+{\int}_{to}^{t}g(s,y(s),Ty(s))ds$$ have uniformly Lipschitz stability and asymptotic behavior by imposing conditions on the perturbed part $\int_{to}^{t}g(s,y(s),Ty(s))ds$ and the fundamental matrix of the unperturbed system y' = f(t, y).

• The Research Journal of the Costume Culture
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• v.17 no.5
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• pp.758-768
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• 2009

This study aims to analyze contemporary women's sense of fashion aesthetic by looking into the design and trend of T-panties, which have now carved out a new niche in the world's 21st century female underwear markets. By this, I'd like to reassure readers of the importance of T-panties, which has only been recently recognized, and more generally suggests the future direction of prominent T-panty design development. This study aims to analyze contemporary women's sense of fashion aesthetic by looking into the design and trend of T-panties, which have now carved out a new niche in the world's 21st century female underwear markets. By this, I'd like to reassure readers of the importance of T-panties, which has only been recently recognized, and more generally suggests the future direction of prominent T-panty design development. The domestic formativeness of all styles is divided into three types: modern feminine, mono-bosom, and utopian narcissist image. This study is baseds on the documents study.

• The Mathematical Education
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• v.29 no.1
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• pp.41-45
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• 1990

S. Z. Wang, B. Y. Li, Z. M. Gao and K. Iseki proved some fixed point theorems on expansion mappings, which correspond some contractive mappings. In a recent paper, B. E. Rhoades generalized the results for in of mappings. In this paper, we obtain the following theorem, which generalizes the result of B. E. Rhoades. THEOREM. Let A, B, S and T be mappings from a complete metric space (X, d) into itself satisfying the following conditions: (1) ${\Phi}$(d(A$\chi$, By))$\geq$d(Sx, Ty) holds for all x and y in X, where ${\Phi}$ : R$\^$+/ \longrightarrowR$\^$+/ is non-decreasing, uppersemicontinuous and ${\Phi}$(t) < t for each t > 0, (2) A and B are surjective, (3) one of A, B, S and T is continuous, and (4) the pairs A, S and B, T are compatible. Then A, B, S and T have a unique common fixed point in X.

• Journal of the Korea Convergence Society
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• v.7 no.4
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• pp.33-38
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• 2016

DDoS attack has been continuously utilized that caused the excessively large amount of traffic that network bandwidth or server was unable to deal with paralyzing the service. Most of the people regard NTP as the biggest cause of DDoS. However, according to recently executed DDoS attack, there have been many SSDP attack in the use of amplified technique. According to characteristics of SSDP, there is no connection for making a forgery of source IP address and amplified resources feasible. Therefore, it is frequently used for attack. Especially, as it is mostly used as a protocol for causing DDoS attack on IoT devices that constitute smart home including a wireless router, media server, webcam, smart TV, and network printer. Hereupon, it is anticipated for servers of attacks to gradually increase. This might cause a serious threat to major information of human lives, major government bodies, and company system as well as on IoT devices. This study is intended to identify DDoS attack techniques in the use of weakness of SSDP protocol occurring in IoT devices and attacking scenario and counter-measures on them.

• Bulletin of the Korean Mathematical Society
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• v.29 no.2
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• pp.295-300
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• 1992

In [5] it was shown that if T .mem. L(X) is regular on a Banach space X, with finite dimensional intersection T$^{-1}$ (0).cap.T(X) and if S .mem. L(X) is invertible, commute with T and has sufficiently small norm then T - S in upper semi-Fredholm, and hence essentially one-one, in the sense that the null space of T - S is finite dimensional ([4] Theorem 2; [5] Theorem 2). In this note we extend this result to incomplete normed space.

• Korean Journal of Food Science and Technology
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• v.12 no.4
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• pp.313-323
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• 1980

The objective of this experiment was to improve the quality and shortening the aging time of Kochujang by adding mixed starter cultures of yeast strains. Kochujangs were mashed during the summer season with mixed starter cultures of Saccharomyces rouxii, Torulopsis versatilis and Torulopsis etchellsii. Enzyme activities and chemical composition of the Kochujang were determined during the period of aging and their organoleptic values were tested. The maximum activities of liquefying amylase and saccharogenic amylase in the Kochujang were obtained during 20 to 60 days and 20 to 30 days after mashing respectively. The acidic protease activity was reached maximum during 20 to 40 days. All enzyme activities were decreased markedly during the final stage of aging period. Among mixed starter cultures tested, mixed culture of T. versatilis and T. etchellsii shows the highest liquefying and saccharogenic amylase activities. Ethyl alcohol contents in 10 days after mashing were highest in the Kochujang with S. rouxii and T. versatilis, followed in order of S. rouxii and T. etchellsii mixture, T. versatilis and T. etchellsii mixture and control without addition of yeast. But the contents in all sample became similar after 20 days with the level of 2.3 to 2.8% and then decreased gradually. The level of reducing sugar contents was markedly increased during the first 10 days, especially in the batches of T. versatilis and T. etchellsii mixture and control. However, the concentration became similar in all samples after 40 days. The contents of amino nitrogen were increased markedly during the first 10 days then slowly up to 90 days. The rate was high in the Kochujang with T. versatilis and T. etchellsii when compared with others. The organoleptic values of all Kochujang made with addition of yeast starter cultures were superior to control, especially in flavor, taste and color. The Kochujang with T. versatilis and T. etchellsii marked the highest value. The data obtained from this experiment suggests that the quality of Kochujang could be improved by using starter culture of suitable yeast strains according to product characteristics and aging time.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.1001-1004
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• 2018

As the industry generates a lot of data, it is increasingly dependent on the IoT platform. For this reason, the performance and anomaly detection of IoT platform is becoming an important factor. In this paper, we propose a system model of IoT platform that detects device anomaly without performance issue. The proposed system uses Micro Batch which calculates the data transmission cycle to provide Soft Real-time service. In the industry, it was difficult to collect abnormal data, so the Hotelling's $T^2$ model was applied to the data analysis experiment. And the Hotelling's $T^2$ model successfully detected anomalies.

• Journal of Korean Society for Quality Management
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• v.25 no.3
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• pp.11-21
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• 1997

The mean residual life(MRL) function gives the expected remaining life of a item at age t. In particular F is said to be an increasing intially then decreasing MRL(IDMRL) distribution if there exists a turing point $t^*\ge0$ such that m(s)$\le$ m(t) for 0$$\le s$\le$ t $t^*$, m(s)$\ge$ m(t) for $t^*\le$ s$\le$ t. If the preceding inequality is reversed, F is said to be a decreasing initially then increasing MRL(DIMRL) distribution. Hawkins, et al.(1992) proposed test of H0 : F is exponential versus$H_1$: F is IDMRL, and $H_0$ versus $H_1$' : F is DIMRL when turning point is unknown. Their test is based on a complete random sample $X_1$, …, $X_n$ from F. In this paper, we generalized Hawkins-Kochar-Loader test to random censored data.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.357-362
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• 2006

OLEDs are becoming established as a commercially viable flat panel display technology of choice of the $21^{st}$ century because of its lightweight, fast response time, lower thickness than LCD's and potentially low cost (1-2). For the OLEDs to function effectively, highly thermally stable materials, which offer high efficiency and long operational lifetimes are required. To achieve long lifetime, highly stable charge (both holes and electrons) transporters are essential. OLED-T provides these materials as well as fluorescent and phosphorescent dopants. This paper reports a unique patented hole injector (E9363) and an electron transporter (E246) that increases the lifetime and efficiency and reduces operating voltage. Further, an electron injector, EEI-101, which evaporates at a very low temperature of $300^{\circ}C$ as opposed to the conventional LiF, which requires $580^{\circ}C$, is also presented.