• Title/Summary/Keyword: 역할인지

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Effect of Ketanserin and Positive End Expiratory Pressure Ventilation on Hemodynamics and Gas Exchange in Experimental Acute Pulmonary Embolism (실험적 급성 폐동맥색전증에서 Ketanserin과 Positive End Expiratory Pressure Ventilation이 혈류역학 및 환기에 미치는 영향)

  • Lee, Sang-Do;Lee, Young-Hyun;Han, Sung-Koo;Shim, Young-Soo;Kim, Keun-Youl;Han, Yong-Chol
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.2
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    • pp.135-146
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    • 1993
  • Background: In acute pulmonary embolism it has been postulated that the constriction of bronchi and pulmonary artery secondary to neurohumoral response plays an important role in cardiopulmonary dysfunction in addition to the mechanical obstruction of pulmonary artery. Serotonin is considered as the most important mediator. Positive end expiratory pressure (PEEP) stimulates $PGI_2$ secretion from the vascular endothelium, but its role in acute pulmonary embolism is still in controversy. Methods: To study the cardiopulmonary effect and therapeutic role of Ketanserin, selective antagonist of 5-HT2 receptor, and PEEP in acute pulmonary embolism experimental acute pulmonary embolism was induced in dogs with autologous blood clot. The experimental animals were divided into 3 groups, that is control group, Ketanserin injection group and PEEP application group. Results: Thirty minutes after embolization, mean pulmonary arterial pressure and pulmonary vascular resistance increased and cardiac output decreased. $PaO_2,\;P\bar{v}O_2$ and oxygen transport decreased and physiological shunt and $PaCO_2$ increased. After injection of Ketanserin, comparing with control group, mean pulmonary arterial pressure, pulmonary vascular resistance and physiological shunt decreased, while cardiac output, $PaO_2$ and oxygen transport increased. All these changes sustained till 4 hours after embolization. After PEEP application pulmonary vascular resistance, $PaO_2$ and $PaCO_2$ increased, while physiological shunt, cardiac output and oxygen transport decreased. After discontinuation of PEEP, mean pulmonary arterial pressure and pulmonary vascular resistance decreased and were lower than control group, while $PaO_2$ and cardiac output increased and higher than control group. $PaCO_2$ decreased but showed no significant difference comparing with control group. Conclusion: It can be concluded that Ketanserin is effective for the treatment of acute pulmonary embolism. With PEEP hemodynamic status deteriorated, but improved better than control group after discontinuation of PEEP. Thus PEEP may be applied carefully for short period in acute pulmonary embolism if the hemodynamic status is tolerable.

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The Significance of IL-10, IL-12, IFN-$\gamma$ and ADA in Tuberculous Pleural Fluid (결핵성 흉수에서 IL-10, IL-12, IFN-$\gamma$, ADA 측정의 의의)

  • Jeon, Doo-Soo;Yun, Sang-Myung;Park, Sam-Seok;Lee, Hyo-Jin;Kim, Yun-Seong;Lee, Min-Ki;Park, Soon-Kew
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.2
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    • pp.301-310
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    • 1998
  • Background: Cell mediated immune response mediated by interaction between CD4+ T lymphocytes and macrophagies is thought to play an important role in tuberculous pleurisy. This interaction is dependent on the interplay of various cytokines. The immunologic response of tuberculous pleurisy is thought to depend on the balance between helper T cell(Th1) cytokine Interleukin-12, Interferon gamma and Th2 cytokine IL-4, IL-10. To understand immunologic mechanism in tuberculous pleurisy and evaluate diagnostic value of these cytokines, the concentrations of Th1 cytokine IL-12, IFN -$\gamma$ and Th2 cytokine IL-10 were measured in tuberculous pleurisy and malignant pleural effusion group. Material and Methods: The concentrations of IL-10, IL-12 and IFN-$\gamma$ were measured by ELISA method in pleural fluids and serums of 20 patients with tuberculous pleurisy and 20 patients with malignant pleural effusion ADA activities were measured by spetrophotomery in pleural fluids of both groups. Results: In tuberculous pleurisy, the mean concentrations of IL-10, IL-12 and IFN-$\gamma$ of pleural fluids showed $121.3{\pm}83.7$ pg/mL, $571.4{\pm}472.7$ pg/mL and $420.4{\pm}285.9$ pg/mL. These were significantly higher than that of serum, $21.2{\pm}60.9$ pg/mL, 194.5 pg/mL, $30.1{\pm}18.3$ pg/mL respectively(p< 0.01). In malignant pleural effusion, the mean concentrations of IL-10, IL-12 and IFN-$\gamma$ of pleural fluids showed $88.4{\pm}40.4$ pg/mL, $306.5{\pm}271.1$ pg/mL and $30.5{\pm}54.8$ pg/mL respectively. Compared with that of serum ($43.4{\pm}67.2$ pg/mL, $206.8{\pm}160.6$ pg/mL, $14.6{\pm}3.3$ pg/mL), only IL-10 was significantly higher (p<0.001), but IL-12, IFN-$\gamma$ were not significant. In tuberculous pleural effusion compared with malignant pleural effusion, the concentration of IL-12, IFN-$\gamma$, ADA were significantly higher (p=value 0.046, <0.001, <0.001), but IL-10 was not significant. For differential diagnosis of tuberculous pleurisy from malignant pleural effusion, using cut-off value of IL-12, IFN-$\gamma$, ADA as 300 pg/mL. 100 pg/mL, 45 U/L, the sensitivity/specificity were 60%/70%, 90%/87.5%, 85%/90% respectively. Conclusion: In tuberculous pleurisy, IL-10, IL-12 and IFN-$\gamma$ were selectively concentrated highly in pleural space than serum. Compared with malignant pleural effusion, IL-12 and IFN-$\gamma$ were significantly higher, but IL-10 were not in tuberculous pleural effusion. The results suggest that Th1 pathway contributes to immune resistant mechanism in tuberculous pleurisy. IFN-$\gamma$ and ADA revealed useful methods of differential diagnosis in tuberculous pleurisy from malignant pleural effusion.

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TEMPOROSPATIAL PATTERNS OF PROGRAMMED CELL DEATH DURING EARLY DEVELOPMENT OF THE MOUSE EMBRYOS (생쥐 배자발생초기의 세포자기사 발현 양상에 관한 연구)

  • Baik, Byeong-Ju;Lee, Seung-Ik;Kim, Jae-Gon;Park, Byung-Yong;Park, Byung-Keon
    • Journal of the korean academy of Pediatric Dentistry
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    • v.28 no.4
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    • pp.709-727
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    • 2001
  • The pattern of programmed cell death(PCD) has been examined during the early developmental period of development in mouse embryos, from embryonic day 4.5(E4.5) to E11.5 Embryos from Balb/c breedings were harvested at various embryonic stages between E4.5 and El1.5. Cell death was analysed by in situ terminal deoxynucleotidyl transferase mediated dUTP nick end labeling(TUNEL) staining in tissue sections and whole embryos. At the blastocyst stage(E4.5), a very few apoptotic cells were found in the inner cell mass of the blastocyst. In the early egg cylinder stage(35.0-5.5), a few apoptotic cells were detected in the embryonic ectoderm, the embryonic endoerm and the proamniotic cavity. In the advanced egg cylinder stage(E5.5-6.5), TUNEL-posifive cells were observed in the extra-embryonic ectoderm and extra-embryonic endoderm as well as in the embryonic ectoderm, embryonic visceral endoderm and proamniotic cavity. In the streak stage(E6.75-7.75), many TUNEL-positive cells were found in the ectoplacental cone. In contrast, only very few apoptotic cells were found in the chorion and extra-embryonic endoderm in extra-embryonic regions. In intra-embryonic region, a few apoptotic cells were randomly found in the embryonic ectoderm, mesoderm and visceral endoderm. At the early somitogenesis stage(E8.0-8.5), most apoptotic cells were observed in the most cranial portion of neural fold (neural ectoderm and adjacent ectoderm). At the mid somitogenesis stage(39.0-9.5), the otic placode first showed TUNEL-positive at this stage. Small number of TUNEL-positive cells were also first seen around optic placode and branchial arches. Three streams of TUNEL-positive cells were clearly seen in the cranial region at 59.5-9.75. At E10.5, apoptotic cells were localized in the developing eye, the junctional portion of medial nasal, lateral nasal and maxillary processes, the lateral portion of branchial arches, the junction of bilateral mandibular processes, and apical ectodermal ridges of limb buds. At E11.5, apoptotic cells were noticeably decreased in most area, except the developing limbs and several somites in the tail region. In this study, the global temporospatial pattern of PCD throughout early development of mouse embryos was discussed. It may provide the basis for further studies on its role in the morphogenesis of the embryo.

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Export Control System based on Case Based Reasoning: Design and Evaluation (사례 기반 지능형 수출통제 시스템 : 설계와 평가)

  • Hong, Woneui;Kim, Uihyun;Cho, Sinhee;Kim, Sansung;Yi, Mun Yong;Shin, Donghoon
    • Journal of Intelligence and Information Systems
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    • v.20 no.3
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    • pp.109-131
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    • 2014
  • As the demand of nuclear power plant equipment is continuously growing worldwide, the importance of handling nuclear strategic materials is also increasing. While the number of cases submitted for the exports of nuclear-power commodity and technology is dramatically increasing, preadjudication (or prescreening to be simple) of strategic materials has been done so far by experts of a long-time experience and extensive field knowledge. However, there is severe shortage of experts in this domain, not to mention that it takes a long time to develop an expert. Because human experts must manually evaluate all the documents submitted for export permission, the current practice of nuclear material export is neither time-efficient nor cost-effective. Toward alleviating the problem of relying on costly human experts only, our research proposes a new system designed to help field experts make their decisions more effectively and efficiently. The proposed system is built upon case-based reasoning, which in essence extracts key features from the existing cases, compares the features with the features of a new case, and derives a solution for the new case by referencing similar cases and their solutions. Our research proposes a framework of case-based reasoning system, designs a case-based reasoning system for the control of nuclear material exports, and evaluates the performance of alternative keyword extraction methods (full automatic, full manual, and semi-automatic). A keyword extraction method is an essential component of the case-based reasoning system as it is used to extract key features of the cases. The full automatic method was conducted using TF-IDF, which is a widely used de facto standard method for representative keyword extraction in text mining. TF (Term Frequency) is based on the frequency count of the term within a document, showing how important the term is within a document while IDF (Inverted Document Frequency) is based on the infrequency of the term within a document set, showing how uniquely the term represents the document. The results show that the semi-automatic approach, which is based on the collaboration of machine and human, is the most effective solution regardless of whether the human is a field expert or a student who majors in nuclear engineering. Moreover, we propose a new approach of computing nuclear document similarity along with a new framework of document analysis. The proposed algorithm of nuclear document similarity considers both document-to-document similarity (${\alpha}$) and document-to-nuclear system similarity (${\beta}$), in order to derive the final score (${\gamma}$) for the decision of whether the presented case is of strategic material or not. The final score (${\gamma}$) represents a document similarity between the past cases and the new case. The score is induced by not only exploiting conventional TF-IDF, but utilizing a nuclear system similarity score, which takes the context of nuclear system domain into account. Finally, the system retrieves top-3 documents stored in the case base that are considered as the most similar cases with regard to the new case, and provides them with the degree of credibility. With this final score and the credibility score, it becomes easier for a user to see which documents in the case base are more worthy of looking up so that the user can make a proper decision with relatively lower cost. The evaluation of the system has been conducted by developing a prototype and testing with field data. The system workflows and outcomes have been verified by the field experts. This research is expected to contribute the growth of knowledge service industry by proposing a new system that can effectively reduce the burden of relying on costly human experts for the export control of nuclear materials and that can be considered as a meaningful example of knowledge service application.

A Study on Developing a VKOSPI Forecasting Model via GARCH Class Models for Intelligent Volatility Trading Systems (지능형 변동성트레이딩시스템개발을 위한 GARCH 모형을 통한 VKOSPI 예측모형 개발에 관한 연구)

  • Kim, Sun-Woong
    • Journal of Intelligence and Information Systems
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    • v.16 no.2
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    • pp.19-32
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    • 2010
  • Volatility plays a central role in both academic and practical applications, especially in pricing financial derivative products and trading volatility strategies. This study presents a novel mechanism based on generalized autoregressive conditional heteroskedasticity (GARCH) models that is able to enhance the performance of intelligent volatility trading systems by predicting Korean stock market volatility more accurately. In particular, we embedded the concept of the volatility asymmetry documented widely in the literature into our model. The newly developed Korean stock market volatility index of KOSPI 200, VKOSPI, is used as a volatility proxy. It is the price of a linear portfolio of the KOSPI 200 index options and measures the effect of the expectations of dealers and option traders on stock market volatility for 30 calendar days. The KOSPI 200 index options market started in 1997 and has become the most actively traded market in the world. Its trading volume is more than 10 million contracts a day and records the highest of all the stock index option markets. Therefore, analyzing the VKOSPI has great importance in understanding volatility inherent in option prices and can afford some trading ideas for futures and option dealers. Use of the VKOSPI as volatility proxy avoids statistical estimation problems associated with other measures of volatility since the VKOSPI is model-free expected volatility of market participants calculated directly from the transacted option prices. This study estimates the symmetric and asymmetric GARCH models for the KOSPI 200 index from January 2003 to December 2006 by the maximum likelihood procedure. Asymmetric GARCH models include GJR-GARCH model of Glosten, Jagannathan and Runke, exponential GARCH model of Nelson and power autoregressive conditional heteroskedasticity (ARCH) of Ding, Granger and Engle. Symmetric GARCH model indicates basic GARCH (1, 1). Tomorrow's forecasted value and change direction of stock market volatility are obtained by recursive GARCH specifications from January 2007 to December 2009 and are compared with the VKOSPI. Empirical results indicate that negative unanticipated returns increase volatility more than positive return shocks of equal magnitude decrease volatility, indicating the existence of volatility asymmetry in the Korean stock market. The point value and change direction of tomorrow VKOSPI are estimated and forecasted by GARCH models. Volatility trading system is developed using the forecasted change direction of the VKOSPI, that is, if tomorrow VKOSPI is expected to rise, a long straddle or strangle position is established. A short straddle or strangle position is taken if VKOSPI is expected to fall tomorrow. Total profit is calculated as the cumulative sum of the VKOSPI percentage change. If forecasted direction is correct, the absolute value of the VKOSPI percentage changes is added to trading profit. It is subtracted from the trading profit if forecasted direction is not correct. For the in-sample period, the power ARCH model best fits in a statistical metric, Mean Squared Prediction Error (MSPE), and the exponential GARCH model shows the highest Mean Correct Prediction (MCP). The power ARCH model best fits also for the out-of-sample period and provides the highest probability for the VKOSPI change direction tomorrow. Generally, the power ARCH model shows the best fit for the VKOSPI. All the GARCH models provide trading profits for volatility trading system and the exponential GARCH model shows the best performance, annual profit of 197.56%, during the in-sample period. The GARCH models present trading profits during the out-of-sample period except for the exponential GARCH model. During the out-of-sample period, the power ARCH model shows the largest annual trading profit of 38%. The volatility clustering and asymmetry found in this research are the reflection of volatility non-linearity. This further suggests that combining the asymmetric GARCH models and artificial neural networks can significantly enhance the performance of the suggested volatility trading system, since artificial neural networks have been shown to effectively model nonlinear relationships.

The Framework of Research Network and Performance Evaluation on Personal Information Security: Social Network Analysis Perspective (개인정보보호 분야의 연구자 네트워크와 성과 평가 프레임워크: 소셜 네트워크 분석을 중심으로)

  • Kim, Minsu;Choi, Jaewon;Kim, Hyun Jin
    • Journal of Intelligence and Information Systems
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    • v.20 no.1
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    • pp.177-193
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    • 2014
  • Over the past decade, there has been a rapid diffusion of electronic commerce and a rising number of interconnected networks, resulting in an escalation of security threats and privacy concerns. Electronic commerce has a built-in trade-off between the necessity of providing at least some personal information to consummate an online transaction, and the risk of negative consequences from providing such information. More recently, the frequent disclosure of private information has raised concerns about privacy and its impacts. This has motivated researchers in various fields to explore information privacy issues to address these concerns. Accordingly, the necessity for information privacy policies and technologies for collecting and storing data, and information privacy research in various fields such as medicine, computer science, business, and statistics has increased. The occurrence of various information security accidents have made finding experts in the information security field an important issue. Objective measures for finding such experts are required, as it is currently rather subjective. Based on social network analysis, this paper focused on a framework to evaluate the process of finding experts in the information security field. We collected data from the National Discovery for Science Leaders (NDSL) database, initially collecting about 2000 papers covering the period between 2005 and 2013. Outliers and the data of irrelevant papers were dropped, leaving 784 papers to test the suggested hypotheses. The co-authorship network data for co-author relationship, publisher, affiliation, and so on were analyzed using social network measures including centrality and structural hole. The results of our model estimation are as follows. With the exception of Hypothesis 3, which deals with the relationship between eigenvector centrality and performance, all of our hypotheses were supported. In line with our hypothesis, degree centrality (H1) was supported with its positive influence on the researchers' publishing performance (p<0.001). This finding indicates that as the degree of cooperation increased, the more the publishing performance of researchers increased. In addition, closeness centrality (H2) was also positively associated with researchers' publishing performance (p<0.001), suggesting that, as the efficiency of information acquisition increased, the more the researchers' publishing performance increased. This paper identified the difference in publishing performance among researchers. The analysis can be used to identify core experts and evaluate their performance in the information privacy research field. The co-authorship network for information privacy can aid in understanding the deep relationships among researchers. In addition, extracting characteristics of publishers and affiliations, this paper suggested an understanding of the social network measures and their potential for finding experts in the information privacy field. Social concerns about securing the objectivity of experts have increased, because experts in the information privacy field frequently participate in political consultation, and business education support and evaluation. In terms of practical implications, this research suggests an objective framework for experts in the information privacy field, and is useful for people who are in charge of managing research human resources. This study has some limitations, providing opportunities and suggestions for future research. Presenting the difference in information diffusion according to media and proximity presents difficulties for the generalization of the theory due to the small sample size. Therefore, further studies could consider an increased sample size and media diversity, the difference in information diffusion according to the media type, and information proximity could be explored in more detail. Moreover, previous network research has commonly observed a causal relationship between the independent and dependent variable (Kadushin, 2012). In this study, degree centrality as an independent variable might have causal relationship with performance as a dependent variable. However, in the case of network analysis research, network indices could be computed after the network relationship is created. An annual analysis could help mitigate this limitation.

Analysis of the Time-dependent Relation between TV Ratings and the Content of Microblogs (TV 시청률과 마이크로블로그 내용어와의 시간대별 관계 분석)

  • Choeh, Joon Yeon;Baek, Haedeuk;Choi, Jinho
    • Journal of Intelligence and Information Systems
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    • v.20 no.1
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    • pp.163-176
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    • 2014
  • Social media is becoming the platform for users to communicate their activities, status, emotions, and experiences to other people. In recent years, microblogs, such as Twitter, have gained in popularity because of its ease of use, speed, and reach. Compared to a conventional web blog, a microblog lowers users' efforts and investment for content generation by recommending shorter posts. There has been a lot research into capturing the social phenomena and analyzing the chatter of microblogs. However, measuring television ratings has been given little attention so far. Currently, the most common method to measure TV ratings uses an electronic metering device installed in a small number of sampled households. Microblogs allow users to post short messages, share daily updates, and conveniently keep in touch. In a similar way, microblog users are interacting with each other while watching television or movies, or visiting a new place. In order to measure TV ratings, some features are significant during certain hours of the day, or days of the week, whereas these same features are meaningless during other time periods. Thus, the importance of features can change during the day, and a model capturing the time sensitive relevance is required to estimate TV ratings. Therefore, modeling time-related characteristics of features should be a key when measuring the TV ratings through microblogs. We show that capturing time-dependency of features in measuring TV ratings is vitally necessary for improving their accuracy. To explore the relationship between the content of microblogs and TV ratings, we collected Twitter data using the Get Search component of the Twitter REST API from January 2013 to October 2013. There are about 300 thousand posts in our data set for the experiment. After excluding data such as adverting or promoted tweets, we selected 149 thousand tweets for analysis. The number of tweets reaches its maximum level on the broadcasting day and increases rapidly around the broadcasting time. This result is stems from the characteristics of the public channel, which broadcasts the program at the predetermined time. From our analysis, we find that count-based features such as the number of tweets or retweets have a low correlation with TV ratings. This result implies that a simple tweet rate does not reflect the satisfaction or response to the TV programs. Content-based features extracted from the content of tweets have a relatively high correlation with TV ratings. Further, some emoticons or newly coined words that are not tagged in the morpheme extraction process have a strong relationship with TV ratings. We find that there is a time-dependency in the correlation of features between the before and after broadcasting time. Since the TV program is broadcast at the predetermined time regularly, users post tweets expressing their expectation for the program or disappointment over not being able to watch the program. The highly correlated features before the broadcast are different from the features after broadcasting. This result explains that the relevance of words with TV programs can change according to the time of the tweets. Among the 336 words that fulfill the minimum requirements for candidate features, 145 words have the highest correlation before the broadcasting time, whereas 68 words reach the highest correlation after broadcasting. Interestingly, some words that express the impossibility of watching the program show a high relevance, despite containing a negative meaning. Understanding the time-dependency of features can be helpful in improving the accuracy of TV ratings measurement. This research contributes a basis to estimate the response to or satisfaction with the broadcasted programs using the time dependency of words in Twitter chatter. More research is needed to refine the methodology for predicting or measuring TV ratings.

Light and Electron Microscopy of Gill and Kidney on Adaptation of Tilapia(Oreochromis niloticus) in the Various Salinities (틸라피아의 해수순치시(海水馴致時) 아가미와 신장(腎臟)의 광학(光學) 및 전자현미경적(電子顯微鏡的) 관찰(觀察))

  • Yoon, Jong-Man;Cho, Kang-Yong;Park, Hong-Yang
    • Applied Microscopy
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    • v.23 no.2
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    • pp.27-40
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    • 1993
  • This study was taken to examine the light microscopic and ultrastructural changes of gill and kidney of female tilapia{Oreochromis niloticus) adapted in 0%o, 10%o, 20%o, and 30%o salt concentrations, respectively, by light, scanning and transmission electron microscope. The results obtained in these experiments were summarized as follows: Gill chloride cell hyperplasia, gill lamellar epithelial separation, kidney glomerular shrinkage, blood congestion in kidneys and deposition of hyalin droplets in kidney glomeruli, tubules were the histological alterations in Oreochromis niloticus. Incidence and severity of gill chloride cell hyperplasia rapidly increased together with increase of salinity, and the number of chloride cells in gill lamellae rapidly increased in response to high external NaCl concentrations. The ultrastructure by scanning electron microscope(SEM) indicated that the gill secondary lamella of tilapia(Oreochromis niloticus) exposed to seawater, were characterized by rough convoluted surfaces during the adaptation. Transmission electron microscopy(TEM) indicated that mitochondria in chloride cells exposed to seawater, were both large and elongate and contained well-developed cristae. TEM also showed the increased chloride cells exposed to seawater. The presence of two mitochondria-rich cell types is discussed with regard to their possible role in the hypoosmoregulatory changes which occur during seawater-adaptation. Most Oreochromis niloticus adapted in seawater had an occasional glomerulus completely filling Bowman's capsule in kidney, and glomerular shrinkage was occurred higher in kidney tissues of individuals living in 10%o, 20%o, 30%o of seawater than in those living in 0%o of freshwater, and blood congestion was occurred severer in kidney tissues of individuals living 20%o, 30%o of seawater than in those living in 10%o of seawater. There were decreases in the glomerular area and the nuclear area in the main segments of the nephron, and that the nuclear areas of the nephron cells in seawater-adapted tilapia were of smaller size than those from freshwater-adapted fish. Our findings demonstrated that Oreochromis niloticus tolerated moderately saline environment and the increased body weight living in 30%o was relatively higher than that living in 10%o in spite of histopathological changes.

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A Mobile Landmarks Guide : Outdoor Augmented Reality based on LOD and Contextual Device (모바일 랜드마크 가이드 : LOD와 문맥적 장치 기반의 실외 증강현실)

  • Zhao, Bi-Cheng;Rosli, Ahmad Nurzid;Jang, Chol-Hee;Lee, Kee-Sung;Jo, Geun-Sik
    • Journal of Intelligence and Information Systems
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    • v.18 no.1
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    • pp.1-21
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    • 2012
  • In recent years, mobile phone has experienced an extremely fast evolution. It is equipped with high-quality color displays, high resolution cameras, and real-time accelerated 3D graphics. In addition, some other features are includes GPS sensor and Digital Compass, etc. This evolution advent significantly helps the application developers to use the power of smart-phones, to create a rich environment that offers a wide range of services and exciting possibilities. To date mobile AR in outdoor research there are many popular location-based AR services, such Layar and Wikitude. These systems have big limitation the AR contents hardly overlaid on the real target. Another research is context-based AR services using image recognition and tracking. The AR contents are precisely overlaid on the real target. But the real-time performance is restricted by the retrieval time and hardly implement in large scale area. In our work, we exploit to combine advantages of location-based AR with context-based AR. The system can easily find out surrounding landmarks first and then do the recognition and tracking with them. The proposed system mainly consists of two major parts-landmark browsing module and annotation module. In landmark browsing module, user can view an augmented virtual information (information media), such as text, picture and video on their smart-phone viewfinder, when they pointing out their smart-phone to a certain building or landmark. For this, landmark recognition technique is applied in this work. SURF point-based features are used in the matching process due to their robustness. To ensure the image retrieval and matching processes is fast enough for real time tracking, we exploit the contextual device (GPS and digital compass) information. This is necessary to select the nearest and pointed orientation landmarks from the database. The queried image is only matched with this selected data. Therefore, the speed for matching will be significantly increased. Secondly is the annotation module. Instead of viewing only the augmented information media, user can create virtual annotation based on linked data. Having to know a full knowledge about the landmark, are not necessary required. They can simply look for the appropriate topic by searching it with a keyword in linked data. With this, it helps the system to find out target URI in order to generate correct AR contents. On the other hand, in order to recognize target landmarks, images of selected building or landmark are captured from different angle and distance. This procedure looks like a similar processing of building a connection between the real building and the virtual information existed in the Linked Open Data. In our experiments, search range in the database is reduced by clustering images into groups according to their coordinates. A Grid-base clustering method and user location information are used to restrict the retrieval range. Comparing the existed research using cluster and GPS information the retrieval time is around 70~80ms. Experiment results show our approach the retrieval time reduces to around 18~20ms in average. Therefore the totally processing time is reduced from 490~540ms to 438~480ms. The performance improvement will be more obvious when the database growing. It demonstrates the proposed system is efficient and robust in many cases.

NFC-based Smartwork Service Model Design (NFC 기반의 스마트워크 서비스 모델 설계)

  • Park, Arum;Kang, Min Su;Jun, Jungho;Lee, Kyoung Jun
    • Journal of Intelligence and Information Systems
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    • v.19 no.2
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    • pp.157-175
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    • 2013
  • Since Korean government announced 'Smartwork promotion strategy' in 2010, Korean firms and government organizations have started to adopt smartwork. However, the smartwork has been implemented only in a few of large enterprises and government organizations rather than SMEs (small and medium enterprises). In USA, both Yahoo! and Best Buy have stopped their flexible work because of its reported low productivity and job loafing problems. In addition, according to the literature on smartwork, we could draw obstacles of smartwork adoption and categorize them into the three types: institutional, organizational, and technological. The first category of smartwork adoption obstacles, institutional, include the difficulties of smartwork performance evaluation metrics, the lack of readiness of organizational processes, limitation of smartwork types and models, lack of employee participation in smartwork adoption procedure, high cost of building smartwork system, and insufficiency of government support. The second category, organizational, includes limitation of the organization hierarchy, wrong perception of employees and employers, a difficulty in close collaboration, low productivity with remote coworkers, insufficient understanding on remote working, and lack of training about smartwork. The third category, technological, obstacles include security concern of mobile work, lack of specialized solution, and lack of adoption and operation know-how. To overcome the current problems of smartwork in reality and the reported obstacles in literature, we suggest a novel smartwork service model based on NFC(Near Field Communication). This paper suggests NFC-based Smartwork Service Model composed of NFC-based Smartworker networking service and NFC-based Smartwork space management service. NFC-based smartworker networking service is comprised of NFC-based communication/SNS service and NFC-based recruiting/job seeking service. NFC-based communication/SNS Service Model supplements the key shortcomings that existing smartwork service model has. By connecting to existing legacy system of a company through NFC tags and systems, the low productivity and the difficulty of collaboration and attendance management can be overcome since managers can get work processing information, work time information and work space information of employees and employees can do real-time communication with coworkers and get location information of coworkers. Shortly, this service model has features such as affordable system cost, provision of location-based information, and possibility of knowledge accumulation. NFC-based recruiting/job-seeking service provides new value by linking NFC tag service and sharing economy sites. This service model has features such as easiness of service attachment and removal, efficient space-based work provision, easy search of location-based recruiting/job-seeking information, and system flexibility. This service model combines advantages of sharing economy sites with the advantages of NFC. By cooperation with sharing economy sites, the model can provide recruiters with human resource who finds not only long-term works but also short-term works. Additionally, SMEs (Small Medium-sized Enterprises) can easily find job seeker by attaching NFC tags to any spaces at which human resource with qualification may be located. In short, this service model helps efficient human resource distribution by providing location of job hunters and job applicants. NFC-based smartwork space management service can promote smartwork by linking NFC tags attached to the work space and existing smartwork system. This service has features such as low cost, provision of indoor and outdoor location information, and customized service. In particular, this model can help small company adopt smartwork system because it is light-weight system and cost-effective compared to existing smartwork system. This paper proposes the scenarios of the service models, the roles and incentives of the participants, and the comparative analysis. The superiority of NFC-based smartwork service model is shown by comparing and analyzing the new service models and the existing service models. The service model can expand scope of enterprises and organizations that adopt smartwork and expand the scope of employees that take advantages of smartwork.