• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권5호
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• pp.859-876
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• 2010

In this paper, we propose a hierarchical application traffic classification system as an alternative means to overcome the limitations of the port number and payload based methodologies, which are traditionally considered traffic classification methods. The proposed system is a new classification model that hierarchically combines a binary classifier SVM and Support Vector Data Descriptions (SVDDs). The proposed system selects an optimal attribute subset from the bi-directional traffic flows generated by our traffic analysis system (KU-MON) that enables real-time collection and analysis of campus traffic. The system is composed of three layers: The first layer is a binary classifier SVM that performs rapid classification between P2P and non-P2P traffic. The second layer classifies P2P traffic into file-sharing, messenger and TV, based on three SVDDs. The third layer performs specialized classification of all individual application traffic types. Since the proposed system enables both coarse- and fine-grained classification, it can guarantee efficient resource management, such as a stable network environment, seamless bandwidth guarantee and appropriate QoS. Moreover, even when a new application emerges, it can be easily adapted for incremental updating and scaling. Only additional training for the new part of the application traffic is needed instead of retraining the entire system. The performance of the proposed system is validated via experiments which confirm that its recall and precision measures are satisfactory.

• 약학회지
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• 제45권1호
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• pp.116-124
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• 2001

Nitric oxide is a labile, gaseous, broad spectrum second messenger that used in various tissues and cells. If it is induced by endogenously and exogenously in the neuronal cells, it is able to mediate analgesia or hyperalgesia at the periphery and in the spinal level respectively. This dual role of nitric oxide in the sensory system is very intriguing but has not been fully understood yet. In this experiment, acetylcholine (300 $\mu$g/paw), sodium nitroprusside (600 $\mu$g/paw), and L-arginine (300 $\mu$g/paw) represented antinociceptive effect to noxious topical stimulus, but pronociceptive responses followed by spinally application (20$\mu$g/5$\mu$l, 10$\mu$g/3$\mu$l, 500$\mu$g/5$\mu$l respectively). Calcium ion is critical element which activates nitric oxide synthase, therefore verapamil (300 $\mu$g/paw) and NOS inhibitor (20 mg/kg, L-NAME or L-NOArg) are injected into right hind paw (i.pl.). When verapamil is combined with NOS inhibitors analgesic effects through NO-cGMP pathway are inhibited as compared with ACh alone. Diluted formalin (2.5%), when injected into rats'hind paw (0.05 ml), elicited a biphasic algesic responses and nitric oxide had an analgesic effect on both $A\delta$ and C sensory nerve fibers which manipulate the phases respective1y. Nitric oxides, which produced from constitutive nitric oxide synthase, activated cyclooxygenase-type I and then prostaglandins are produced from them. So, indomethacin and ibuprofen, inhibitors of COX$_1$enzyme, when pretreated intraperitoneally (100 mg/kg) could reduce the hyperalgesic state. From these results, it is possible to imagine that the intrathecally administered NO donors expressed hyperalgesia through both long-term potentiation mechanism and arachidonic acid-prostaglandin cascade.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.445-454
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• 2007

Background: Phosphatidic acid(PA), an important second messenger, is involved in inflammation. Notably, cell-cell interactions via adhesion molecules playa central role in inflammation. This thesis show that PA induces expression of intercellular adhesion molecule-1(ICAM-1) on macrophages and describe the signaling pathways. Materials and methods: Macrophages were cultured in the presence of 10% FBS and assayed cell to cell adhesion using HUVEC. For the gene and protein analysis, RT-PCR, Western blot and flow cytometry were performed. In addition, overexpressed cell lines for dominant negative PKC-${\delta}$ mutant established and tested their effect on the promoter activity and expression of ICAM-1 protein by PA. Results: PA-activated macrophages significantly increased adhering to human umbilical vein endothelial cell and this adhesion was mediated by ICAM-1. Pretreatment with rottlerin(PKC-${\delta}$ inhibitor) or expression of a dominant negative PKC-${\delta}$ mutant, but not Go6976(classical PKC-${\alpha}$ inhibitor) and myristoylated PKC-${\xi}$ inhibitor, attenuated PA-induced ICAM-1 expression. The p38 mitogen-activated protein kinase(MAPK) inhibitor blocked PA-induced ICAM-1 expression in contrast, ERK upstream inhibitor didn't block ICAM-1. Conclusion: These data suggest that PA-induced ICAM-1 expression and cell-cell adhesion in macrophages requires PKC-${\delta}$ activation and that PKC-${\delta}$ activation is triggers to sequential activation of p38 MAPK.

• Journal of Korean Dental Science
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• 제10권2호
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• pp.45-52
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• 2017

Calcium has versatile roles in diverse physiological functions. Among these functions, intracellular $Ca^{2+}$ plays a key role during the secretion of salivary glands. In this review, we introduce the diverse cellular components involved in the saliva secretion and related dynamic intracellular $Ca^{2+}$ signals. Calcium acts as a critical second messenger for channel activation, protein translocation, and volume regulation, which are essential events for achieving the salivary secretion. In the secretory process, $Ca^{2+}$ activates $K^+$ and $Cl^-$ channels to transport water and electrolyte constituting whole saliva. We also focus on the $Ca^{2+}$ signals from intracellular stores with discussion about detailed molecular mechanism underlying the generation of characteristic $Ca^{2+}$ patterns. In particular, inositol triphosphate signal is a main trigger for inducing $Ca^{2+}$ signals required for the salivary gland functions. The biphasic response of inositol triphosphate receptor and $Ca^{2+}$ pumps generate a self-limiting pattern of $Ca^{2+}$ efflux, resulting in $Ca^{2+}$ oscillations. The regenerative $Ca^{2+}$ oscillations have been detected in salivary gland cells, but the exact mechanism and function of the signals need to be elucidated. In future, we expect that further investigations will be performed toward better understanding of the spatiotemporal role of $Ca^{2+}$ signals in regulating salivary secretion.

• Archives of Pharmacal Research
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• 제19권3호
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• pp.201-206
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• 1996

Nitric oxide (NO) is thought to be a second messenger involved in secretion. Upon stimulating pancreatic acinar cells with cholecystokinin-pancreozymin (CCK-PZ), NO formation has been shown to be associated with increased levels of cGMP (Seo et al., 1995). To elucidate the signaling pathway of VIP-induced enzyme secretion, we investigated the NO and cGMP synthesis steps as potential steps where two signal pathways triggered by CCK-PZ and VIP interact. The results obtained in this work provide evidence that increase in pancreatic enzyme secretion by treatment with VIP has no relationship with NOS activity and cGMP level. This conclusion was derived from the following findings that VIP treatment of rat pancreatic tissue increased amylase release as well as protein output in a dose- and time-dependent manner, whereas NOS activity and cGMP synthesis were not affected by VIP treatment as monitored by NOS activity assay and determining cGMP level, which was further confirmed by a NOS-inhibitor study. Consequently, CCK-PZ or VIP increases enzyme secretion in rat pancreatic tissue, but the two hormones are different in their mode of action. Together the results suggest that signaling pathway of VIP-induced enzyme secretion might either bypass the NO and cGMP synthesis steps or lie on a distinct pathway from CCK-PZ-induced pathway.

• 한국의상디자인학회지
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• 제9권3호
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• pp.167-180
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• 2007

This study analyzes the Asian, African and Latin American cultural hybrids in modem fashion, and offers a direction for desirable cultural hybrids in modem fashion. First, the cultural hybrids have been considered in two aspect: global hybrids and structural hybrids. Second, the trends of Asian, African and Latin American cultural hybrids have been interpreted differently depending on the cultural backgrounds of each area. However, the cultural hybrid representing the change of tradition in Asia, Africa and Latin America is a common trend, and is used to describe the social changes. Third, this study examines the global hybrid trend in modem fashion based on the hybrid trend of Asian, African and Latin American culture found in the four major collections from 2000 S/S to 2005 F/W. Until recently, the exotic images have been determined in the viewpoint of Western world, and utilization by the world-renowned designers in the four major collections plays the major role in converting the regional cultural elements into global ones. Fourth, this study also examines the structural hybrids in modem fashion based on the hybrid trend found in Asian, African and Latin American designer collections between 2000 S/S and 2005 F/W. The works which are connected to the world trend, but are also rooted from the cultural and regional traditions demonstrate the globalization of the Asian, African and Latin American fashion. Fashion is a messenger of a culture, and its importance as a symbol of a cultural trend is growing.

• 한국융합학회논문지
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• 제12권10호
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• pp.235-248
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• 2021

본 연구는 스마트폰을 통해 의사소통하는 사용자들이 느끼는 외로움에 미치는 선행변수를 도출하기 위해 수행되었다. 특히, 관계적 특성, 사회적 특성, 의사소통 특성 등을 반영하여 3가지 특성이 외로움에 미치는 영향을 실증적으로 분석했다. 분석 결과는 다음과 같다. 첫째, 갈등 해결 능력을 대인 간 갈등과 외로움에 유의한 영향을 미치는 것으로 나타났다. 둘째, 사회적 스트레스는 대인 간 갈등, 의사소통 피로감, 외로움 등에 유의한 영향을 미치는 것으로 나타났다. 셋째, 의사소통 부족은 갈등 해결 능력과 외로움에 유의한 영향을 미치는 것으로 나타났다. 마지막으로, 의사소통 피로감은 외로움에 유의한 영향을 미치는 것으로 나타났다. 이러한 결과는 개인이 느끼는 외로움을 감소시키기 위해서 자신과 타인 간의 관계 속에서 발생할 수 있는 갈등을 현명하게 해결할 수 있는 능력을 지속해서 향상할 필요가 있으며, 타인과의 관계 형성에 대한 두려움이나 부담감을 떨쳐버릴 필요가 있다는 것을 알 수 있다.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.73-86
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• 2003

Endothelins secreted from keratinocytes are intrinsic madiators for human melanocytes in UVB-induced pigmentation. Antimelanogenic ingredient, 1,2-Ο-diferulylglycerol(SM709) isolated from bamboo extract inhibited the melanin synthesis of Bl6F10 melanoma cells by 62%. To understand the cellular mechanism of antimelanogenic activity of SM709 in human melanocytes, the effects of SM709 on the ET-l-induced $Ca^{2+}$ mobilization were investigated. ET-l receptors in human melanocytes were characterized by using specific antagonist and found that ET-l increased intracellular $Ca^{2+}$ by activating ET-B receptor. SM709 completely blocked the ET-l-induced intracellular $Ca^{2+}$ increase and its inhibitory effect showed dose- and time- dependent manners. To investigate the role of SM709 on intracellular $Ca^{2+}$ store, when the $Ca^{2+}$ store was partially depleted by thapsigargin; a specific inhibitor of ER-type $Ca^{2+}$-ATPase, caffeine-induced $Ca^{2+}$ mobilization did not changed in the presence or absence of SM709, suggesting that SM709 has no effect on the $Ca^{2+}$ store. It is known that LPA receptor and P$_2$ receptor are linked to InsP$_3$ second messenger system. When these receptors in melanocytes were activated by LPA and ATP, the intracellular $Ca^{2+}$ signaling was observed even in the presence of SM709. From the above results, it can be suggested that SM709 has an antimelanogenic activity by antagonizing the ET-B receptor, resulting in subsequent intracellular $Ca^{2+}$ signaling, in UV induced pigmentation.nduced pigmentation.

• 실천공학교육논문지
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• 제15권1호
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• pp.13-22
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• 2023

본 논문의 목적은 온라인 PBL(Problem Based Learning)이 학습자의 4C 역량과 학습 경험에 미치는 영향을 탐색하는 것이다. 연구 결과 첫째, 온라인 PBL이 학습자의 문제해결능력, 의사소통능력, 예비교사효능감에 통계적으로 유의미한 영향을 미치는 것으로 나타났다. 둘째, 학습자들은 온라인 PBL 경험에 매우 만족했으며, 학습과 예비교사로서의 자신에게 매우 도움이 된다고 인식했다. 셋째, 학습자들은 실시간 화상회의 시스템과 메신저가 온라인 PBL을 성공적으로 수행하는 데 매우 도움이 된다고 인식하는 것으로 나타났다. 넷째, 온라인 PBL을 성공적으로 수행하기 위한 중요요인에 대해 본 연구 참여자들은 의사소통과 성실성이 매우 중요하다고 인식하고 있었고, 리더의 역할도 중요하지만 팀원 간의 개인적 친밀도는 상대적으로 덜 중요하다고 인식하고 있었다. 다섯째, 학습자들은 온라인 PBL을 성공적으로 수행하기 위해서는 교수자의 피드백이 매우 중요하다고 인식하고 있는 것으로 나타났다. 마지막으로 본 연구의 시사점과 함께 향후 연구에 대한 제언을 논의하였다.

• 유통과학연구
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• 제14권9호
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• pp.85-94
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• 2016

Purpose - Recently, Mobile technologies and devices including smart phones and tablets have increased the possibility of communicating with other people and sharing personal information without time and space restriction. In order to realize the market potential related to mobile technologies, a large number of internet services have been incorporated into mobile platforms. Especially, The number of MIM(Mobile Instant Messenger) users has been increasing dramatically and services using MIM platform also have diversified. In spite of drastic growth in markets related to MIM, there is little empirical research on MIM and users' behaviors. This study designed to examine the structural relationships among belongingness, loneliness, self-disclosure intention, system quality, and self-disclosure behavior in context of MIM. Research design, data, and methodology - Three hypotheses were about the relationship among belongingness, loneliness and self-disclosure intention. The other two hypotheses were about the moderating effect of system quality in the causal relationship between self-disclosure intention and self-disclosure behavior. The data was analyzed by structural equation modeling. Research data were obtained from 330 undergraduate students who were KakaoTalk users and total 314 valid questionnaires were used in the final analysis. Results - The results from this study are as follow. First, the belongingness and the loneliness had a significant impact on self-disclosure intention in MIM. Second, the self-disclosure intention in MIM also had a positive impact on the self-disclosure behavior. Lastly, there is a moderating effect of the system quality in the relationship between the self-disclosure intention and self-disclosure behavior in MIM. Specifically, the higher system quality level was perceived, the positive effect of the self-disclosure intention in MIM on the self-disclosure behavior was greater. Conclusions - Based on the results from this study, academic and practical implications can be drawn. First, the study extends the scope of research about SNS through focusing on MIM to be classified by closed type SNS and identifies the relationship between emotion, behavioral intention and behaviors in MIM. Second, this study provides strategic guidelines to increase the efficiency for promotion activity. Limitations for the study also should be discussed.