• Title/Summary/Keyword: Challenge Model

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An Animal Model to Evaluate the Protective Efficacy of Haemophilus influenzae Type b Conjugate Vaccines

  • Kim Hyun Sung;Yoo Tae Hyeon;Jang Yang Suk;Kim Hun;Park Jin Yong;Hur Byung Ki;Ryu Yeon Woo;Kim Jong Su
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.6
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    • pp.490-494
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    • 2004
  • An efficacy test of PRP (polyribosylribitol phosphate)-TT (Tetanus toxoid) conjugate vaccines was carried out using BALB/c mice as an animal model by inoculating Haemophilus in­fluenzae type b (Hib) with a virulence enhancement factor (VEF). Three administrations of the conjugate vaccines at 2-week intervals elicited a significantly high level of PRP antibodies (P>0.0001). The protective activity of the PRP immunization was challenged with either Hib with iron dextran (Hib/) or with a combination of mucin and hemoglobin (Hibmh) as a VEF. The me­dium lethal dose $(LD_{50})$ for Hibmh and Hibiwas measured as 10 CFU (Colony Forming Unit) and $2.5{\times}10^{8}$ CFU respectively. Each immunized animal was challenged with five or ten times the $LD_{50}$ level of bacteria with a VEF. A significant difference in mortality between the immunized and control mice (P> 0.01) was observed with the Hibmh challenge inoculation but not with the Hibi challenge inoculation. These results show that a combination of mucin and hemoglobin was able to enhance the virulence of Hib in BALB/c mice to cause a lethal infection, thus suggesting that BALB/c mice introduced to this method can be an effective model animal for testing the protective efficacy of H. influenzae conjugate vaccines.

Sequential Speaker Classification Using Quantized Generic Speaker Models (양자화 된 범용 화자모델을 이용한 연속적 화자분류)

  • Kwon, Soon-Il
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.44 no.1
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    • pp.26-32
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    • 2007
  • In sequential speaker classification, the lack of prior information about the speakers poses a challenge for model initialization. To address the challenge, a predetermined generic model set, called Sample Speaker Models, was previously proposed. This approach can be useful for accurate speaker modeling without requiring initial speaker data. However, an optimal method for sampling the models from a generic model pool is still required. To solve this problem, the Speaker Quantization method, motivated by vector quantization, is proposed. Experimental results showed that the new approach outperformed the random sampling approach with 25% relative improvement in error rate on switchboard telephone conversations.

Amelioration of Asthmatic-Related Symptoms by an Aqueous Extract of Angelica archangelica L. (신선초의 물 추출물에 의한 천식 증상의 감소)

  • Heo, Jin-Chul;Lee, Sang-Han
    • Journal of Life Science
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    • v.18 no.10
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    • pp.1336-1341
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    • 2008
  • Inflammation through the respiratory tract is a crucial event in immune disorders, including asthma, and atopic rhinitis. To investigate whether an aqueous extract of Angelica archangelica L. (AaL) has a beneficial influence in terms of anti-asthmatic activity, its effects on an ovalbumin-induced asthmatic model were examined. Mice sensitized to ovalbumin were orally administered the AaL extract, and their lungs examined by Haematoxylin-Eosin staining to determine IL-4/13 cytokine expression. The AaL extract exerted strong anti-asthmatic effects by regulating each level in the $CD4^+$ cell number, IL-4/13, and other target markers in the lungs. Together, these results collectively indicate that the aqueous AaL extract ameliorates asthmatic symptoms effectively in a mouse ovalbumin-challenge model.

Bridging the Gap Between Science and Industry: The Fraunhofer Model

  • Klingner, Raoul;Behlau, Lothar
    • STI Policy Review
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    • v.3 no.2
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    • pp.130-151
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    • 2012
  • Fraunhofer was founded in 1949 and grew into Europe's largest application-oriented research organization. Fraunhofer currently employs over 20,000 members in Germany, is internationally networked, and manages an R&D budget of over 1,8 Billion Euros per year. An important step for Fraunhofer to become an integral component of the German innovation system was the introduction of the Fraunhofer Model of financing based on a performance-related system of financial management. The underlying model of the allocation and distribution of public funding to Fraunhofer that is subsequently allotted to specific research groups is one of the success factors of Fraunhofer. Fraunhofer is proud of its decentralized organizational model. Fraunhofer is comprised of 60 Institutes in Germany working in different fields, under one legal framework, and with a strong brand value. Every Fraunhofer Institute is affiliated with a German University and every institute director simultaneously holds a chair at the affiliated university. It is a challenge for the headquarter organization to balance the intended competition of individual Fraunhofer Institutes with complementarity cooperation in science among Fraunhofer-Institutes, especially when coming from different knowledge domains; however, this goal results in a significant advantage. The unique strengths of Fraunhofer offer system solutions in a world with increasingly complex R&D challenges. While growing to become the largest organization on Europe to focus on applied research it is the challenge to remain an agile organization that is flexible in organizational structure. Fraunhofer has reached a well-recognized position in the European innovation landscape. It is often referred to by science and governments as a role model for innovation policy and a key element of the latest successes in the German economy that has recovered quicker from the latest economic crisis than most other western economies. The paper explains Fraunhofer as an organizational paradigm and its underlying management model to elaborate on the challenges of managing a research organization. We wish to show how it is possible to transfer the management model and philosophy of Fraunhofer to innovation systems with different framework conditions and challenges. A universal conclusion may be drawn based on the description of Fraunhofer; however, changes in existing structures and innovation systems cannot be implemented over night.

The Internet Business Model of Selling Products or Services (제품/서비스를 판매 및 이용하는 인터넷 비즈니스 모델)

  • 이기백;최문기
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2000.04a
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    • pp.165-173
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    • 2000
  • Some people think that the Internet is a tool of making the current market as a perfect competition market and that the business model of selling products or services is not attractive. But research of this issue propose that the Internet give us new challenge of business. The objective of this study is to analyze the properties of Internet and Internet business and to evolute the Internet business model of selling products or services and to suggest survival strategies in fierce competition circumstances.

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Lifetime Prediction of a P.S.C Rail Road Bridge (P.S.C 철도교량의 잔존수명 예측)

  • Yang Seung-Le
    • Journal of the Korean Society for Railway
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    • v.8 no.5
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    • pp.439-443
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    • 2005
  • The biggest challenge bridge agencies face is the maintenance of bridges, keeping them safe and serviceable, with limited funds. To maintain the bridges effectively, there is and urgent need to predict their remaining life from a system reliability viewpoint. In this paper, a model using lifetime functions to evaluate the overall system probability of survival of a rail road bridge is proposed. In this model, the rail load bridge is modeled as a system. Using the model, the lifetime of the rail road bridge is predicted.

Early Bronchoconstriction After Allergen Challenge of Nonanesthetized Guinea Pigs (Ovalbumin으로 감작된 기니픽에서 Allergen 흡입으로 인한 즉시형 기관지 수축반응에 대한 비침습적 측정)

  • Kim, Je-Hyeong;Shim, Jae-Jeong;Lee, Sung-Yong;Kwon, Young-Hwan;Lee, So-Ra;Lee, Sang-Youb;Cho, Jae-Youn;In, Kwang-Ho;Yoo, Se-Hwa;Kang, Kyung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.1
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    • pp.99-106
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    • 1998
  • Background: Bronchial asthma is a complex disease, which is characterized by spontaneous exacerbations of airway obstruction and persistent bronchial hyperresponsiveness. Animal models have fallen short of reproducing the human disease, particularly in mimicking the spontaneous and persistent airflow obstruction that characterized in asthma. In animals, airflow obstruction is usually assessed by measuring airflow resistance during tidal breathing under such invasive technique as tracheostomy and anesthesia. A noninvasive technique for measuring pulmonary function in small animals is needed to evaluate long-term changes in lung function during the course of experimentally produced disease without sacrificing the animal. Purpose: The purpose of this study was to evaluate early bronchoconstrcition after allergen challenge and airway responsiveness (AR) to inhaled methacholine in nonanethetized, unrestrained guinea pigs. Method: Guinea pig model of asthma was sensitized by subcutaneous injection with ovalbumin and challenged by inhalation of aerosolized ovalbumin(1% wt/vol ovlabumin). Airflow obstruction of conscious guinea pig was measured as specific airway resistance (airway resistance $\times$ thoracic gas volume). Airway resistance and thoracic gas volume of conscious guinea pig were assessed by body plethysmography before challenge and at regular intervals for as long as 30 minutes after challenge. AR to aerosolized methacholine of asthma group was compared with that of control group in body plethysmography. Result: Asthma model<> developed in 13 (65%) among 20 guinea pigs, in which early responses occurred in the airways after the exposure to inhalation with ovalbumin. Airway challenge with ovalbumin caused increase in specific airway resistance, which peaked at 6 minutes and amounted to a $231.5{\pm}30.4%$ increase from baseline. AR to aerosolized methacholine of asthma model increased significantly compared with control group. Conclusion: These results have showed a useful animal model to evaluate early bronchoconstrcition after allergen challenge and airway responsiveness in nonanethetized, unrestrained guinea pigs.

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Experimental Infection for the Neutralization of White Spot Syndrome Virus (WSSV) in Wild Captured Sand Shrimp, Crangon affinis (자연산 자주새우(Crangon affinis)에서 흰반점바이러스(WSSV)의 neutralization을 위한 인위감염(experimental infection))

  • Gong, Soo-Jung;Kim, Yeong-Jin;Choi, Mi-Ran;Kim, Sung-Koo
    • Journal of Life Science
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    • v.20 no.9
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    • pp.1294-1298
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    • 2010
  • White spot syndrome virus (WSSV) is one of the most virulent viral agents threatening the penaeid shrimp culture industry. This study was carried out to evaluate the susceptibility of the sand shrimp, Crangon affinis, to WSSV as an alternative experimental model. WSSV caused 100% mortality in C. affinis within 7 days after experimental infection by immersion. Based on challenge studies, it was confirmed that C. affinis could be a potential host in WSSV transmission. Also, the neutralization of WSSV was carried out using an antiserum raised against recombinant envelop protein rVP466 to evaluate the WSSV infection mechanism. A constant amount of WSSV (at $1{\times}10^4$ diluted stocks) was incubated with various amounts of antiserum and then mixed to 20 l reservoir for the immersion challenge of C. affinis for neutralization. At 5 days post challenge, the shrimp in the positive control immersed in the immersion reservoir containing WSSV stock showed 100% mortality. The shrimps challenged with the 3 different mixtures of WSSV and rVP466 antiserum (1:0.1, 1:0.5 and 1:1) showed 100%, 68.8% and 68.8% mortality at 14 days post challenge, respectively. These results indicated that the antiserum raised against rVP466 could block WSSV infection in C. affinis. Therefore, this study confirmed that C. affinis can be naturally infected by WSSV as another potential host and that C. affinis can be used as an alternative experimental animal instead of penaeid shrimps.

Ad Planning Model by Comparison Challenge Approach in the e-Marketplace (e-Marketplace에서의 비교도전에 의한 광고계획 모델)

  • 이재규;이재원
    • Journal of Intelligence and Information Systems
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    • v.9 no.3
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    • pp.137-153
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    • 2003
  • Comparison shopping is the most popular functionality in the e-Marketplace. Most of their revenue has been generated kent the Internet advertisement, but the ad earning was declined as the ad costing per action method widespread. Seller less familiar to the customer shrinks from chances for advertising and exposing their products. So, we need an efficient methodology subject to the seller's ad budget and other constraints, and it also has to increase comparison broker's earning in the e-Marketplace. Our research proposed and developed an ad planning methodology using comparison challenge approach which can be applied by 3$^{rd}$ party comparison brokers. Comparison challenge planning is organized with challenge policy of competitor level, product level and specification level. With that policies and basic challenge propositions, we measure the quantified value of functional distance between the specifications of my product and competitor's product. My product challenges the comparison using the comparative ad format to the similar but inferior competitor's product based on quantified valuation. Comparison challenge planning system has two phases of comparative value generation and optimization. We developed a prototype system and applied it to the desktop PC market of five major manufacturers. Our performance was emphasized by comparing to other comparative ad methods such as random display method and minimum distance method..

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An Empirical Study on the Flow Experience Affected by Characteristics of Mobile Internet (모바일 인터넷 특성이 플로우 경험에 미치는 영향에 관한 연구)

  • Yoo, Sang-Jin;Choi, Eun-Bin;Kim, Hyo-Jung
    • Information Systems Review
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    • v.8 no.1
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    • pp.125-139
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    • 2006
  • Recently, as mobile internet users grow rapidly, mobile internet companies are experiencing a fierce competition to capture new customers. Under this business environment, they try to identify factors that make people use mobile internet in order to satisfy customers by providing better and diversified services. There has been enormous effort to analyze customers' behavior in choose and use mobile internet services. However, there is no one best methodology to identify factors to attract customers yet. Thus, the study applied the flow construct proposed by Csikszentmihalyi(1977) and expanded by Hoffman and Novak(1996) to identify environmental factors of internet which has impact on users' mobile internet usage. To implement the study, the following activities have been done: literature reviews on service acceptance model and flow structure, questionnaire survey, suggestion of the flow model on mobile internet, and hypothesis test. For the study, 242 out of 307 samples collected were statistically analyzed using SPSS 10.0, AMOS 4.0 statistics package. The findings of this study are as follows: First, mobile internet environment factors influencing on challenge of flow antecedent were media characteristics(use of convenience, transmission quality), contents characteristics(uniqueness, timeliness, simplicity). Second, mobile internet environment factors influencing on skill of flow antecedent were contents(uniqueness, timeliness, simplicity), charge(definiteness and diversity of charge), usage(security, instant connectivity). Third, challenge of flow antecedent had a significant effect on flow of mobile internet usage. But it was not statistically significant that skill has an influence on flow. This study discovered the relationship between mobile internet environment factors(media characteristics, contents characteristics, charge characteristics, usage characteristics) and flow experience of mobile internet users which would be a valuable insight for marketing strategies. Results shows that challenge of flow antecedent have a significant impact on flow experience in mobile internet environment. Additional, media characteristics, contents characteristics of mobile internet environment factors is positively correlated with challenge of flow antecedent. In other words, mobile internet companies should provide customers with diverse service and take a challenging attitude to get customers show aggressive attitude in mobile internet usage.