• Journal of the Korean Ceramic Society
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• v.33 no.10
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• pp.1170-1176
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• 1996

Porous silicon was prepared by anodic reaction. The process was controlled by current density and etching time an the thickness change and the room temperature PL was measured. The thickness of porous silicon was increased with etching time and was decreased after critical time. It was the same as increasing current density. It needed only 15 sec to electropolish the surface of porous silicon above current density 70 mA/cm2. We can understand that increasing etching time leads narrow size of Si column by porous silicon formation mechanism. And the sample with narrow Si column revealed PL blue shift. The specimens were heated in the range of 300-1000$^{\circ}C$ in order to see PL changes. The heat treatment was proceeded in H2 atmosphere vacuum system to avoid oxidation. The PL was disappeared above 600$^{\circ}C$. In high temperature some sintered Si columns were observed in SEM photography. There was no difference of -Hx bonds which was suggested as evidence of hydride compounds luminescence between 500$^{\circ}C$ and 600$^{\circ}C$. Thus it is concluded that quantum confinement is major factor of PL of porous silicon.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.5999-6003
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• 2014

Pesticides used in Korea are grouped by four classes of hazard (extremely, highly, moderately and slightly hazardous) based on acute oral and dermal toxicity in the rat. However, there is little information of carcinogenic effects. The aim of this study was to evaluate potential carcinogenicity for active ingredients of pesticides used in Korea. A total of 1,283 pesticide items were registered under the Pesticide Control Act of which 987 were commercially available. Of these 987 items, 360 active ingredients not duplicated were evaluated for carcinogenicity using the carcinogen list established by the US Environmental Protection Agency (EPA). Some 25 out of 360 ingredients were classified as likely to be carcinogenic (probable) to humans and 52 had suggestive evidence of carcinogenic potential (suspected) based on the US EPA classification. Some 31% of 987 items contained probable or suspected human carcinogenic ingredients. Carcinogenic pesticides accounted for 24% (5,856/24,795 tons) of the total volume of consumption in Korea. Interestingly, pesticides with lower acute toxicity were found to have higher carcinogenic potential. Based on these findings, the study suggests that it is important to provide information on long-term toxicity to farmers, in addition to acute toxicity data.

• Progress in Medical Physics
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• v.29 no.3
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• pp.81-91
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• 2018

Particulate matter (PM) in dust causes serious pathological conditions, and it has been considered a critical health issue for many years. Respiratory disorders such as bronchitis, asthma, and chronic inflammation, are the most common illnesses due to PM that appears as dust. There is evidence that cardiovascular and neurological abnormalities are caused by PM. Although an extensive amount of work has been conducted on this topic, including studies on the nature of the particles, particle size measurements, particle distribution upon inhalation, the health effects of fine particles, disease prevention, diagnosis, and treatment, to this date, there is still a considerable lack of knowledge in these areas. Therefore, the identification of the key components that cause diseases owing to PM, and the specific diagnoses of the diseases, is important. This review will explore the current literature on the origin and nature of PM and their effects on human health. In addition, it will also highlight the approaches that have been adopted in order to diagnose the effects of PM using positron emission tomography (PET) or single-photon emission computerized tomography (SPECT).

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.41-50
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• 2020

The paper aims to investigate auditors, auditing firms and other external factors that affect quality of information technology audit in Vietnam. We conducted 2 types of data collections including direct and on survey. For direct survey, we sent directly to auditors at the training classes organized by State Securities Exchanges Commission. An online survey was established and Google doc link was provided to the Big4 and non-Big4 auditors. We received 138 survey responses in that 90 auditors came from Big4 and 48 auditors from non-Big4 firms. The data are analyzed using a factor analysis and compare means approaches to illustrate the potential IT audit quality factors and identify differences between two groups of auditors. The results show that independence and accounting knowledge and audit skills are the most important factors. And since external auditors perform many assurance services, the independence is critical. The result also shows that the auditors need to have enough competent and professional skills when conducting an audit, especially within an IT environment that requires high quality. The findings suggest a similar pattern of two groups in the context of Vietnam and some factors of auditors and auditing firms appear to have a statistically significant impact on quality of IT audit.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.1
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• pp.101-121
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• 1997

Consider a Jackson type closed queueing network in which each queue has a single exponential server. Assume that N customers are moving among .kappa. queues. We propose a candidata procedure which yields a lower bound of the network throughput which is sharper than those which are currently available : Let (.rho.$_{1}$, ... .rho.$_{\kappa}$) be the loading vector, let x be a real number with 0 .leq. x .leq. N, and let y(x) denote that y is a function of x and be the unique positive solution of the equation. .sum.$_{i = 1}$$^{\kappa}$y(x) .rho.$_{i}$ (N - y(x) x $p_{i}$ ) = 1 Whitt [17] has shown that y(N) is a lower bound for the throughput. In this paper, we present evidence that y(N -1) is also a lower bound. In dosing so, we are led to formulate a rather general conjecture on 'quot;Migrating Critical Points'quot; (MCP). The .MCP. conjecture asserts that zeros of successive derivatives of certain rational functions migrate at an accelerating rate. We provide a proof of MCP in the polynomial case and some other special cases, including that in which the rational function has exactly two real poles and fewer than three real zeros.tion has exactly two real poles and fewer than three real zeros.

• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.305-310
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• 2006

The Web is an important source of information for health care consumers, and the resources they find on the Web have a direct affect on their health outcomes. Despite the enormous benefits of online health care, the quality of health information on the Internet is an area of increasing concern. Therefore, there's a need to develop quality assessment tools that can filter out poor quality online health information. The purpose of this study is to explore the critical attributes for assessing website quality and for developing quality assessment measurements. We completed three focus group discussions with 24 participants that were administered by a moderator and based on specifically focused group questions. The results suggest that the most important quality criteria, as identified by the respondents, were related to issues of credibility and accuracy. To determine the credibility of Internet health information, the respondents stated one must consider the following: the information source, disclosure of the author's or organization's credentials/qualifications, disclosure of ownership and the updating of the content. For the accuracy of content, elements such as a statement of purpose, evidence-based information, relevance and completeness should be considered. Interactivity, accessibility, and design were additional quality criteria.

• IMMUNE NETWORK
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• v.10 no.6
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• pp.181-187
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• 2010

Excessive alcohol consumption is one of the critical causative factors leading to alcoholic liver disease (ALD). ALD is characterized by a wide spectrum of liver damage, ranging from simple uncomplicated liver steatosis (fatty liver) to steatohepatitis and liver fibrosis/cirrhosis. It has been believed that the obvious underlying cause for ALD is due to hepatocyte death induced by alcohol itself. However, recent sparkling studies have shown that diverse immune responses contribute to ALD because liver is enriched with numerous immune cells. Especially, a line of evidence has suggested that innate immune cells such as Kupffer cells and natural killer (NK)/NKT cells are significantly involved in the pathogenesis of ALD via production of pro-inflammatory cytokines and other mediators. Indeed, more interestingly, hepatic stellate cells (HSCs), known as a major cell inducing liver steatosis and fibrosis, can be killed by liver NK cells, which could be suppressed by chronic alcohol consumption. In this review, with the view of liver as predominant innate immune organ, we describe the pathogenesis of ALD in which what roles of innate immune cells are and how they are interacting with HSCs.

• Journal of Korean Academy of Nursing
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• v.46 no.2
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• pp.159-167
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• 2016

Purpose: This article provides an overview of current knowledge on the impact of caregiving on the psychological and physical health of family caregivers of intensive care unit (ICU) survivors and suggestions for future research. Methods: Review of selected papers published in English between January 2000 and October 2015 reporting psychological and physical health outcomes in family caregivers of ICU survivors. Results: In family caregivers of ICU survivors followed up to five years after patients' discharge from an ICU, psychological symptoms, manifested as depression, anxiety and post-traumatic stress disorder, were highly prevalent. Poor self-care, sleep disturbances and fatigue were identified as common physical health problems in family caregivers. Studies to date are mainly descriptive; few interventions have targeted family caregivers. Further, studies that elicit unique needs of families from diverse cultures are lacking. Conclusion: Studies to date have described the impact of caregiving on the psychological and physical health in family caregivers of ICU survivors. Few studies have tested interventions to support unique needs in this population. Therefore, evidence for best strategies is lacking. Future research is needed to identify ICU caregivers at greatest risk for distress, time points to target interventions with maximal efficacy, needs of those from diverse cultures and test interventions to mitigate family caregivers' burden.

• BMB Reports
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• v.49 no.9
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• pp.488-496
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• 2016

Estrogens are the key hormones regulating the development and function of reproductive organs in all vertebrates. Recent evidence indicates that estrogens play important roles in the immune system, cancer development, and other critical biological processes related to human well-being. Obviously, the gonads (ovary and testis) are the primary sites of estrogen synthesis, but estrogens synthesized in extra- gonadal sites play an equally important role in controlling biological activities. Understanding non-gonadal sites of estrogen synthesis and function is crucial and will lead to therapeutic interventions targeting estrogen signaling in disease prevention and treatment. Developing a rationale targeting strategy remains challenging because knowledge of extra-gonadal biosynthesis of estrogens, and the mechanism by which estrogen activity is exerted, is very limited. In this review, we will summarize recent discoveries of extra-gonadal sites of estrogen biosynthesis and their local functions and discuss the significance of the most recent novel discovery of intestinal estrogen biosynthesis.

• Journal of Information Technology Services
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• v.6 no.3
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• pp.69-86
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• 2007

As most of firms related with P2P services change their free services into fee-charging services, the problems of intellectual property rights are solved to satisfactory extent. Accordingly, P2P systems become more popular with the general public. In this respect, it is thought to be very important to research on the critical factors affecting usage of P2P systems. Although it is strongly expected that the characteristics of users activities in virtual communities affect the intention to re-use P2P systems, relatively few attention have been paid to this question. Therefore, this paper is to present empirical evidence to explain how the characteristics of users activities in virtual communities affect re-use intention of P2P services. The theoretical contribution of this study is that the characteristics of users activities in virtual communities is theoretically derived from the comprehensive literature review and the logical reasoning, and that the research model of the relationship between the users activities' characteristics in virtual community and the re-use intention of P2P services is proposed and empirically validated, which is expected to expand explaining power of the TAM(Technological Acceptance Model). Also, the practical implication is to provide the guideline to support the successful strategic planning for development and.operation of P2P services through the virtual communities.