• Title/Summary/Keyword: Indirect effect

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A Study on the Factors Affecting the Information Systems Security Effectiveness of Password (패스워드의 정보시스템 보안효과에 영향을 미치는 요인에 관한 연구)

  • Kim, Jong-Ki;Kang, Da-Yeon
    • Asia pacific journal of information systems
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    • v.18 no.4
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    • pp.1-26
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    • 2008
  • Rapid progress of information technology and widespread use of the personal computers have brought various conveniences in our life. But this also provoked a series of problems such as hacking, malicious programs, illegal exposure of personal information etc. Information security threats are becoming more and more serious due to enhanced connectivity of information systems. Nevertheless, users are not much aware of the severity of the problems. Using appropriate password is supposed to bring out security effects such as preventing misuses and banning illegal users. The purpose of this research is to empirically analyze a research model which includes a series of factors influencing the effectiveness of passwords. The research model incorporates the concept of risk based on information systems risk analysis framework as the core element affecting the selection of passwords by users. The perceived risk is a main factor that influences user's attitude on password security, security awareness, and intention of security behavior. To validate the research model this study relied on questionnaire survey targeted on evening class MBA students. The data was analyzed by AMOS 7.0 which is one of popular tools based on covariance-based structural equation modeling. According to the results of this study, while threat is not related to the risk, information assets and vulnerability are related to the user's awareness of risk. The relationships between the risk, users security awareness, password selection and security effectiveness are all significant. Password exposure may lead to intrusion by hackers, data exposure and destruction. The insignificant relationship between security threat and perceived risk can be explained by user's indetermination of risk exposed due to weak passwords. In other words, information systems users do not consider password exposure as a severe security threat as well as indirect loss caused by inappropriate password. Another plausible explanation is that severity of threat perceived by users may be influenced by individual difference of risk propensity. This study confirms that security vulnerability is positively related to security risk which in turn increases risk of information loss. As the security risk increases so does user's security awareness. Security policies also have positive impact on security awareness. Higher security awareness leads to selection of safer passwords. If users are aware of responsibility of security problems and how to respond to password exposure and to solve security problems of computers, users choose better passwords. All these antecedents influence the effectiveness of passwords. Several implications can be derived from this study. First, this study empirically investigated the effect of user's security awareness on security effectiveness from a point of view based on good password selection practice. Second, information security risk analysis framework is used as a core element of the research model in this study. Risk analysis framework has been used very widely in practice, but very few studies incorporated the framework in the research model and empirically investigated. Third, the research model proposed in this study also focuses on impact of security awareness of information systems users on effectiveness of password from cognitive aspect of information systems users.

Relationship between Early Postoperative Renal Scintigraphy and Long-term Transplant Survival (신 이식 직후 신장 스캔 소견과 이식신 장기 생존의 관계)

  • So, Young;Lee, Kang-Wook;Shin, Young-Tai;Ahn, Moon-Sang;Bae, Jin-Sun;Sul, Chong-Koo;Jung, In-Mok
    • The Korean Journal of Nuclear Medicine
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    • v.35 no.4
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    • pp.251-257
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    • 2001
  • Purpose: We investigated the possibility of early postoperative Tc-99m DTPA scintigraphy in predicting long-term renal transplant survival. Materials and Methods: 64 living donor (LD) grafts were divided into two groups according to the graft function on early post-operative renal scintigraphy. Survival analysis was performed using Kaplan-Meier method and Cox proportional hazard model. Chi-square test was performed to evaluate the difference in the frequency of acute rejection. Results: Cumulative renal transplant survival was decreased in 11 patients with abnormal renal scintigraphy, but it was not statistically significant. Decreased graft function on early post-operative renal scintigraphy was not a predictor of long-term graft survival. The frequency of acute rejection was higher in abnormal scintigraphy group, and the difference was statistically significant. Conclusion: Decreased graft function on early post-operative renal scintigraphy has no direct effect on long-term renal transplant survival in LD transplantation. But it may have an indirect elect through increasing the frequency of acute rejection.

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Cytoprotective Effect by Antioxidant Activity of Codonopsis lanceolata and Platycodon grandiflorum Ethyl Acetate Fraction in Human HepG2 Cells (인간 HepG2 세포에서 더덕 및 도라지 에틸아세테이트 분획물의 항산화 효과에 의한 세포보호 효과)

  • Kim, Soo-Hyun;Choi, Hyun-Jin;Oh, Hyun-Taek;Chung, Mi-Ja;Cui, Cheng-Bi;Ham, Seung-Shi
    • Korean Journal of Food Science and Technology
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    • v.40 no.6
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    • pp.696-701
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    • 2008
  • The objective of this study was to determine whether Codonopsis lanceolata or Platycodon grandiflorum ethyl acetate fraction (CLEA or PGEA) protect cells against sodium nitroprusside (SNP)-induced oxidative stress via the expression of various antioxidant systems. The HepG2 cells exposed for 24 hr to 0.5 mM SNP showed a reduction in the cell viability by an MTT assay. Pretreatment with CLEA and PGEA resulted in an inhibition of SNP-induced cell death. In addition, the effects of CLEA and PGEA on the expression of antioxidant systems via RT-PCR analyses was assessed. The levels of catalase (CAT), glucose-6-phosphate dehydrogenase (G6PD) and metallothionein (MT)-1A mRNA were increased after 24 hr of CLEA exposure. The levels of Mn superoxide dismutase CAT, G6PD, MT-1A, and MT-2A mRNA were increased after PGEA treatment. In conclusion, CLEA and PGEA exert indirect antioxidant effects, perhaps via the induction of a variety of antioxidant systems which, may protect cells against oxidative stress.

Microbiological and Pathological Features of Experimentally Induced Leptospirosis in Guinea Pigs (실험적으로 기니픽에 유발시킨 렙토스피라병에 대한 미생물학적 및 병리학적 연구)

  • Chang, Woo-Hyun;Kim, Ik-Sang;Lee, Woo-Kon;Park, Kyung-Hee;Lee, Jae-Ho;Chi, Je-Geun;Lee, Jung-Bin
    • The Journal of the Korean Society for Microbiology
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    • v.21 no.2
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    • pp.211-226
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    • 1986
  • To understand the pathogenesis of anicteric leptospirosis with severe pulmonary hemorrhage occured in Korea, the microbiological and pathological features were observed in the experimentally induced leptospirosis in guinea pigs infected with a virulent strain of Leptospira interrogans isolated from the patient at Wonju, Korea, and the results are summarized as follows. 1. The main pathological features were widespread hemorrhages, especially affecting lung, skeletal muscles, retroperitoneal and perirenal adipose tissues. The hemorrhages accompanied inflammatory process especially of vasculitic pattern as well as occasional coagulation necrosis in the liver, skeletal muscle, and myocardium. The main inflammatory cells were of plasma cell even in the fairly early stage of the infection. 2. Those pathologic changes were more exaggerated in the inoculation site. 3. Within 144 hours of infection, the longer the infection time, the more antigens were observed in the tissues, and the severer the pathologic changes. 4. Leptospiral antigens were detected at first by indirect immunofluorescent and immunoperoxidase technics. As the infection time extended, the antigens were observed in all of the tissues examined except in the skeletal muscle. The shape of the antigens was spiral or thread-like within 72 hours of infection. As the infection progressed, they became fragmented and granular. 5. Leptospires were detected in the blood within 144 hours of infection by darkfield microscopic examination. Thereafter, none was observed. 6. Antibody to leptospires were detected as early as 72 hours of infection. In summary, the virulent strain of L. interrogans used in this experiment induced widespread hemorrhages with inflammatory reaction especially in lung, skeletal muscles, and retroperitoneal adipose tissue. With these findings, it is suggested that the direct toxic effect of leptospires might playa great role in the pathogenesis of this infection.

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Immunological properties of the 30 kDa antigen of Toxoplasma gondii (단클론 항체를 이용하여 정제한 톡소포자충 30 kDa 항원의 면역학적 특성)

  • Lee, Yeong-Hwa;No, Tae-Jin;Sin, Dae-Hwan
    • Parasites, Hosts and Diseases
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    • v.35 no.1
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    • pp.55-62
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    • 1997
  • The molecular weight 30 kDa membrane protein of Toxoplusma Sondii (Toxoplasma 30 kDa) apparently conserved in most strains of T. gondii and sera of infected hosts. The present study aimed to elucidate Toxoplasmc 30 kDa as a useful diagnotic antigen for serodiagnisis of toxoplasmosis by ELISA and for induction of protective immunity. Murine spleen cells immunized with the membrane antigen of T. gondii were fused with mouse Sp2/0-Ag 14 myeloma cells. Out of 8 clones selected, five were IgG2b, the others belonged to IgG 1 and IgG2a. The 30 kDa antigen was distributed mainly on the surface membrane of tachyzoites by indirect fluorescence method. Murine peritoneal macrophages which were activated by 30 kDa antigen produced more amounts of NO2 compared with crude antigen-treated group, however there were no significant differences in toxoplamacidal activity between the two groups. Higher specificity of Toxoplosma 30 kDa antigen was recognized for serodiagnosis of toxoplasmosis than the crude antigen. From these results, ToxopLasmo 30 kDa antigen enhances the cytotoxic effect of macrophages as well as a more reliable means for the serodiagnosis of toxoplasmosis by ELISA. Key words: Toxoplosma gondii, 30 kDa antigen (p30), mouse, serodiagnosis, macrophage, cytotoxicity.

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Effects of Sperm Motility on In Vitro Production of Embryo and Correlation with Mitochondria Amount in Pig

  • Chung, Ki-Hwa;Kim, In-Cheul;Son, Jung-Ho
    • Journal of Embryo Transfer
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    • v.25 no.4
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    • pp.263-266
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    • 2010
  • Prediction of semen's fertilizing ability used in artificial insemination (AI) is one of very important factors on pig reproductive performance. In vitro fertilization (IVF) has been used for indirect evaluation of sperm's fertilizing ability and it has been showed as highly correlated index. In swine industry, increasing interest in preservation of boar semen raises questions on the sperm motility from semen used in commercial AI centers. Mitochondria in sperm mid-piece generate the energy to support motility and could be an explanation of impaired fertility. Objective of this study was to suggest usable sperm motility to farms in measuring the effect of sperm motility and sperm abnormality on in vitro production of embryo in which sperm's fertilizing ability can be determined indirectly. Semen samples were provided from local AI center and used within 3 days after collection. Semen samples were divided by 4 different motile groups (>70%; 61~70%; 51~60%; <50%) using CASA (computer-assisted sperm analysis) on the days of IVF. Developmental rate to the blastocyst stage from over 61% motile sperm group showed significantly higher rate than below 60% motile sperm group ($16.5{\pm}0.7{\sim}18.4{\pm}0.8%$ vs $6.3{\pm}0.8{\sim}11.5{\pm}0.7%$, p<0.05). In experiment to determine the relationship between sperm motility and viability and abnormality, over 61% motile sperm groups showed significantly higher viability rate compared to below 60% motile sperm groups ($84.8{\pm}4.0{\sim}88.1{\pm}4.0%$ vs $69.1{\pm}4.0{\sim}74.2{\pm}4.0%$, p<0.05). On the other hand, morphological sperm abnormality showed significantly higher in over 70% motile sperm group ($10.2{\pm}2.2$ vs $16.0{\pm}2.2{\sim}21.0{\pm}2.2%$, p<0.05). In experiment to find the correlation between sperm motility of 4 different motile groups and amount of mitochondria, lower motility group also showed lower level of mitochondria (p<0.05). The mitochondria parameter used in this study showed another possibility to differentiate the sperm motility. Taken together, because below 60% motile semen used in AI reduce the fertility, AI centers should provide the over 60% motile sperm to the farms at the time of AI.

Classification of Snowfalls over the Korean Peninsula Based on Developing Mechanism (발생기구에 근거한 한반도 강설의 유형 분류)

  • Cheong, Seong-Hoon;Byun, Kun-Young;Lee, Tae-Young
    • Atmosphere
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    • v.16 no.1
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    • pp.33-48
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    • 2006
  • A classification of snowfall type based on development mechanism is proposed using previous snowfall studies, operational experiences, etc. Five types are proposed: snowfall caused by 1) airmass transformation (AT type), 2) terrain effects in a situation of expanding Siberian High (TE type), 3) precipitation systems associated with extratropical cyclones (EC type), 4) indirect effects of extratropical cyclones passing over the sea to the south of the Korean peninsula (ECS type), and 5) combined effects of TE and ECS types (COM type). Snowfall events during 1981-2001 are classified according to the 5 types mentioned above. For this, 118 events, with at least one station with daily snowfall depth greater than 20 cm, are selected. For the classification, synoptic weather charts, satellite images, and precipitation data are used. For TE and COM types, local sea-level pressure chart is also used to confirm the presence of condition for TE type (this is done for events in 1990 and thereafter). The classification shows that 109 out of 118 events can be classified as one of the 5 types. In the remaining 8 events, heavy snowfall occurred only in Ullung Island. Its occurrence may be due to one or more of the following mechanism: airmass transformation, mesoscale cyclones and/or mesoscale convergence over the East Sea, etc. Each type shows different characteristics in location of snowfall and composition of precipitation (i.e., dry snow, rain, and mixed precipitation). The AT-type snowfall occurs mostly in the west coast, Jeju and Ullung Islands whereas the TE-type snowfall occurs in the East coast especially over the Young Dong area. The ECS-type snowfall occurs mostly over the southern part of the peninsula and some east cost area (sometimes, whole south Korea depending on the location of cyclones). The EC- and COM-type snowfalls occur in wider area, often whole south Korea. Precipitation composition also varies with the type. The AT-type has a snow ratio (SR) higher than the mean value. The TE- and EC-type have SR similar to the mean. The ECS- and COM-type have SR values smaller than the mean. Generally the SR values at high latitude and mountainous areas are higher than those at the other areas. The SR value informs the characteristics of the precipitation composition. An SR value larger than 10 means that all precipitation is composed of snow whereas a zero SR value means that all precipitation is composed of rain.

The Structural Relationship among Sense of Coherence, Clinical Practice Stress, and Departmental Satisfaction of Dental Hygiene Students (치위생(학)과 학생의 통합성, 임상실습스트레스, 학과만족도의 구조적 관계)

  • Jeon, Ki Ha;Lim, Soon Ryun;Kim, Mi
    • Journal of dental hygiene science
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    • v.16 no.5
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    • pp.323-330
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    • 2016
  • The purpose of this study was to understand the comprehensive relationship among sense of coherence, clinical practice stress, and major satisfaction of students in the department of dental hygiene. From four local universities, departments of dental hygiene were selected: two departments represented a three-year curriculum system and two represented a four-year curriculum system. Data from the final questionnaires of 319 students were analyzed. Differences between variables were analyzed using t-tests and ANOVAs, and correlations were checked using Pearson's correlation coefficients. Path analysis was conducted to analyze the relationship among clinical practice stress, sense of coherence, and major satisfaction. The results indicated that clinical practice stress had a negative influential relationship with both sense of coherence, and major satisfaction. In addition, sense of coherence had a positive influential relationship with major satisfaction. The direct and indirect effects among factors displayed significant differences, indicating that clinical practice stress has a partial mediation effect on sense of coherence and major satisfaction. Therefore, major satisfaction can be increased by developing and implementing programs to improve sense of coherence.

Effects of Adding Bamboo leaves Powder on the Quality of Jeolpyon (댓잎분말을 첨가한 댓잎절편의 일반성분 및 품질특성)

  • Kim, Duk-Han;Hwang, Su-Jung
    • Korean journal of food and cookery science
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    • v.22 no.6 s.96
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    • pp.869-874
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    • 2006
  • This study investigated the effect of bamboo leaf powder, added at content of 0%, 3%, 6%, 9% and 12%, on the quality and sensory characteristics of rice cake imprinted with flower pattern (Ed-there is no respecitive comparison here) The chemical composition as a whole was 3.07${\pm}$0.12% of moisture, 5.87${\pm}$0.02% of crude protein, 2.52${\pm}$0.05% of crude fat, 23.70${\pm}$0.07% of crude fiber and 7.73${\pm}$0.02% of crude ash. With increasing amount of added bamboo leaf powder, the hardness and chewiness of the cake were significantly increased(p<0.05), while the cohesiveness, springiness and adhesiveness were decreased. In chromaticity, the L-value, the indicator of brightness, was significantly decreased with increasing bamboo leaf powder content. The a-value, the indicator of redness, was significantly lower than the chlorophyll color (p<0.05). The b-value, the indicator of yellowness, was increased indirect proportion to the content. In sensory test, the sensory characteristics such as color, flavor, taste and chewiness were all stronger with increasing powder content, whereas the softness and dampness were weaker. The greatest overall satisfaction was achieved by the sample group of cake with 6% preference added powder.

Relation of Self Leadership and Empowerment and Organization Innovation Action in Private Security Guard (민간경비원의 셀프리더십과 임파워먼트 및 조직혁신행동의 관계)

  • Kim, Kyong-Sik;Kim, Chan-Sun
    • The Journal of the Korea Contents Association
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    • v.12 no.11
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    • pp.377-387
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    • 2012
  • The purpose of this study is to investigate the relationship between self leadership and empowerment and organization innovation action in private security guard. This study established private security guards who is being located in Seoul, 2011 and work in the private security company by population. Using purposive sampling method, 293 samples were drawn and were used for the final analysis. Using SPSSWIN 18.0, frequency analysis, factor analysis, reliability analysis, multiple regression analysis and path analysis were performed. Cronbach's ${\alpha}$ value which shows the reliability of the questionnaire came out to be over .831. The conclusion is following. First, private security guard's self leadership affects to empowerment. That is, influence and semanticity are enlarged as action center strategy, natural compensation strategy is attained well. Also, capacity, self decision power is enlarged as constructive thinking strategy, natural compensation strategy is attained well. Second, private security guard's self leadership affects to organization innovation action. In other words, innovation action is increased as action center strategy is attained well. Also, organization's innovation result is enlarged as constructive thinking strategy, action center strategy, natural compensation strategy are attained well. Third, private security guard's empowerment affects on organization innovation action. That is, innovation action, innovation result appears high in case of influence, semanticity is enlarged. Fourth, private security guard's self leadership exerts direction indirect effect in empowerment and organization innovation action. Thus, empowerment is an important variable that mediate self leadership and organization innovation action.