Earticle

Fluoride compounds through ingestion, inhalation or skin contact hydrolyze to fluoride ion and form corrosive hydrofluoric acid on the mucosa, and also act as a direct cellular poison which interferes with calcium metabolism and enzyme mechanisms to induce hyperkalemia and hypocalcemia, following to dysrhythmias and cardiac arrest. Although fluoride compound is very important substance in forensic science, it is one of the substances that are difficult to be identified by a routine toxicological analysis among all chemicals in the forensic case caused by "unknown" substance or a workplace chemical accident. Identification of fluoride compound often goes beyond the general analytical procedure, so a more systematic procedure should be suggested. This study reviews the analytical results of fluoride compound-related accident cases submitted to the National Forensic Service and presents improved analytical plans. In the case reviewed, hydrogen fluoride, sodium fluoride, ammonium fluoride, sodium fluorosilicate, calcium fluoride, nitrogen trifluoride were identified. These six types of fluoride compounds are suggested as accident preparedness substances that should be considered in forensic analysis of hazardous chemical accident in Korea.

This study was conducted to understand alcohol kinetics for Koreans and to present reasonable parameters for the application of the Widmark equation. A total of 44 healthy adults(11 female and 33 male) was selected and assigned to drink 1 g of ethanol per kg body weight of individual within 1 hour. Blood samples were then collected every 15 min for the first 3 h, 30 min next 3 h, and 1 h last 9 h. All samples were analyzed by gas chromatography with a flame ionization detector(GC-FID) for blood alcohol concentration(BAC). The maximum BAC(Cmax) was 0.145 ± 0.028%(g/100 mL) in average under the controlled experimental condition. Alcohol elimination rates(β-slope) in average were 0.0185 ± 0.0025 %/h for male and 0.0211 ± 0.0025 %/h for female, respectively. Widmark’s factor(rho-factor, r) in average were 0.61 ± 0.060 L/kg for male and 0.56 ± 0.073 L/kg for female. The Widmark alcohol calculation for Koreans is suggested that 1) It cannot be argued about the absorption rate due to the diversity of drinking types 2) The rapid absorption phase is an average of 15 minutes after drinking and there is no significant change in the first 1 hour 3) If the BAC is less than 0.02% or within 90 minutes of the end of drinking, the back-calculation is not possible 4) Estimation of alcohol concentration should be calculated as decreasing from the start time of drinking 5) The elimination rate is 0.0192 ± 0.0027 %/h for drinking driver 6) Widmark's factor should be calculated individually based on height, weight, sex and age.

본 논문에서는 웹기반 동영상 콘텐츠 이용자들의 웹콘텐츠 속성 지각과 관여 행동이 웹콘텐츠 이용 만족도를 매개로 웹콘텐츠 광고 효과(웹콘텐츠 광고에 대한 태도, 웹콘텐츠 간접광고 상품에 대한 태도, 브랜디드 웹콘텐츠의 광고 효과)에 어떠한 영향을 미치는지 살펴보기 위해 탐색적 연구를 수행하였다. 본 연구의 분석 결과, 웹콘텐츠 이용 만족도에 대해 웹콘텐츠 속성 중에서는 오락성, 이용편이성, 경제성 순으로 유의한 관계가 있는 것으로 나타났다. 또한, 노출된 웹콘텐츠에 대한 참여, 추천, 공유 행위 같은 관여 행동도 웹콘텐츠 이용 만족도를 높여주는 것으로 확인되었다. 웹콘텐츠 광고 효과 측면에서는 웹콘텐츠 속성 중 자신과의 부합성, 경제성, 그리고 웹콘텐츠 관여 행동이 모두 유의한 정(+)의 영향을 미치는 것으로 나타났다. 또한, 웹콘텐츠의 이용편이성, 경제성, 오락성, 웹콘텐츠 관여 행동이 웹콘텐츠 이용 만족도를 거쳐 웹콘텐츠 광고 효과에 모두 유의한 정(+)의 영향을 미치는 것으로 나타남으로써, 웹콘텐츠 이용 만족도의 매개적 역할이 확인되었다. 구체적으로, 경제성 인식과 이용자의 웹콘텐츠 관여 행동은 웹콘텐츠 광고 효과에 직접적으로도 영향을 미치는 반면, 오락성과 이용편이성 인식은 웹콘텐츠 이용 만족도를 통해 간접적으로만 웹콘텐츠 광고 효과에 기여하는 것이 확인되었다. 마지막으로, 본 연구 결과가 제시하는 이론적·관리적 시사점을 제시하고, 연구의 한계와 미래의 연구 방향에 대해서도 논의하였다.

In the current paper, we conduct an exploratory research to investigate the impacts of users' attribute perceptions of and involvement behaviors toward web-based video contents on advertising effects of web-based video contents (i.e., attitude toward the ads of web-based video contents, attitude toward the indirect action ads of web-based video contents to promote a particular product or service, and advertising effect of branded web-based video contents), focusing on the mediating role of usage satisfaction of web-based video contents. The findings indicate that (1) three attributes of web-based video contents (i.e., ease of use, economic value, and fun) and involvement behavior toward web-based video contents have positive effects on usage satisfaction of web-based video contents; (2) two attributes of web-based video contents (i.e., congruency and economic value) and involvement behavior toward web-based video contents positively influence the abovementioned advertising effects of web-based video contents; and (3) usage satisfaction of web-based video contents mediates the impacts of three attributes of web-based video contents (i.e., ease of use, economic value, and fun) and involvement behavior toward web-based video contents on the abovementioned advertising effects of web-based video contents. Finally, we discuss the theoretical and practical implications of our findings and develop directions for future research.

본 연구에서는 컨버전스 환경에서 다중 미디어 이용 행태를 다양한 차원-미디어 기기, 플랫폼, 콘텐츠-에서 살펴보았다. 이를 위해 본 연구는 미디어 이용자의 개인 특성으로서 추구 목표(실용적, 쾌락적, 사회적)와 개인 성향(혁신성, 즉시성, 인지추구 성향)에 기초한 시장세분화를 통해, 세분군별로 주 이용 매체로 자리 잡은 4대 스크린 기반 미디어-TV, 컴퓨터(랩톱/PC), 휴대폰, 태블릿PC-를 중심으로 스크린 기반 미디어 행동에 어떻게 차이가 나는지 알아보았다. 이를 통해 본 연구에서는 세분군별 이용자들의 인구통계학적 특성, 미디어 선택과 플랫폼-콘텐츠 조합 등 이용 특성을 파악함은 물론, 세분군에 따라 신규 미디어 기기/서비스의 수용 의향에서도 차이가 있음을 보이고 이에 따른 시사점을 제안하였다.

The current research investigated cross-platform usage behavior in digital convergence environments in terms of various aspects such as media devices, platforms, and contents. Specifically, we first divided media users into segments based on individual characteristics—that is, individual goal pursuit (utilitarian goal, hedonic goal, and social goal) and personal traits (innovativeness, immediacy, and need for cognition). Then, we examined whether the segments differ in usage behavior of four types of screen-based media (TV, PC/laptop computer, mobile phone, and tablet PC). More specifically, we examined whether the segments differ in the demographic characteristics, behavioral characteristics on media usage (e.g., media choice, combination of consumed contents and platforms, etc.), and the adoption intention of new media devices/services.

IPTV서비스가 정부주도의 U-IT839 정책에 광대역융합서비스라는 이름으로 선정된 이래 최근 급격한 변화를 겪고 있다. 지난해 말 3년간의 논란 끝에 IPTV법안이 통과된 후 사업자들이 잇달아 상용화 서비스에 들어감으로써 IPTV 상용화시대가 본격화되었다. 본 연구는 IPTV시장을 둘러싼 환경변화가 가속화되는 시점에서 서비스의 성공적인 안착과 활성화를 위해서는 소비자에 대한 이해가 선행되어야 함에 주목하였다. 이에 3,387명에 이르는 이용자와 비이용자를 대상으로 실증분석을 수행하였다. 본 연구결과에 의하면 IPTV이용경험은 인구통계적 특성, 소비생활태도, 디바이스 기능 및 보유형태, 경쟁미디어 이용행태에 따라 차이가 있는 것으로 나타났으며, 서비스 이용경험에 따라 즐거움, 용이함, 유용함에 대한 인식의 갭이 확인되었다. 다음으로 이용자와 비이용자를 중심으로 서비스 만족도 및 향후 서비스 가입의향에 영향을 미치는 선ㆍ후행 변수를 규명하여 향후 마케팅전략 수립을 위한 기초자료를 제공하였다. 끝으로 이러한 결과의 이론적 및 실무적 시사점이 논의되고 연구의 한계점과 미래 연구방향이 제시되었다

Recently, multimedia industry has undergone a great change since IPTV service was selected as one of the nation’s promising telecommunication services owing to the Korean Government’s U-IT 839 policy. At the end of last year, the legislative bill for IPTV has passed at last after three years of heated discussion. Service providers have introduced real time IPTV one after another and IPTV age is expected to come starting this year. Unfortunately, despite of service provider’s urgent needs to understand consumers more deeply in order for its successful launching, there is a dearth of good literature examining how consumers perceive IPTV. This study tries to investigate consumers’ perception of IPTV and evaluate their attitudes towards the service in depth using quantitative approach. The result suggests that consumers have a conflicting image of IPTV; a positive image such as fun, new, useful, active and speedy and a negative image such as complicated and inconvenient coexist in consumer’s perception of IPTV. The empirical result from 3,387 participants shows that there is a difference in IPTV subscription rate according to demographic variables, consumption behavior, possessed device type and usage pattern of competing services. Also, there exists a gap between users and non-users in how they perceive IPTV in terms of its fun, ease of use and usefulness. In addition, this study provides a guideline for establishing a marketing strategy for IPTV by examining key factors that influence consumer satisfaction and the likeliness to take up the service. Finally, academic and practical implication is made, limitation is clarified and a direction for further studies is suggested.

우리나라 지역별 태양광 발전 보급의 결정요인을 분석하기 위해, 16개 광역지방자치단체의 2006-2015년 기간 동안의 패널자료를 이용하여 태양광 발전량에 미치는 요인을 정책, 환경, 전력, 사회․ 경제 범주로 분류하여 분석하였다. 분석결과, 태양광 발전은 사회경제적 요인에 가장 유의미한 관계를 찾을 수 있었으며, 보조금과 전력 자급률도통계적으로 영향이 있음을 알 수 있었다. 환경적 요인에서 일조시간은 긍정적인 영향이 나타났으나 지리적 잠재량은영향이 크지 않았음을 보여준다.

This study focused on why the solar PV systems of particular regions are installed and expanded faster and bigger than others in Korea. We analyzed the factors affecting solar power generation, by using panel data during from 2006-2015, which we classified into policy, environment, power, and socio-economic factors. As a result of the analysis, we found that photovoltaic was most affected by socio-economic factors, and subsidies and power self-sufficiency rates were also affected. In terms of environmental factors, the sunshine hours had a positive impact, but the geographic potentials did not.

The use of deodorizing plant products such as persimmon leaves, pine needles and fennel seeds to mask the characteristic odor of kimchi has been proposed. Therefore, in this study, the effect of deodorizing plants on kimchi fermentation and the profile of volatile flavor compounds was investigated. During sensory evaluation tests of sour and fermentation odors of kimchi, plant extract-added kimchi showed higher sensory scores than chopped plant-added kimchi. Additionally, kimchi containing pine needle extracts (0.3-0.6%) and fennel seed extracts (0.05-0.1%) showed higher sensory scores than untreated kimchi. In addition, pine needle extract and fennel seed extract had a significant influence on kimchi fermentation characteristics such as pH, total acidity and the concentration of lactic acid bacteria. The volatile flavor compounds of kimchi and deodorizing plant extracts were also analyzed using GC/MS and the correlation of volatile flavor compounds in kimchi, plant extracts and plant-added kimchi was examined. The results revealed that the sour and fermentation odors of kimchi were reduced using deodorizing plant extracts by changing the kimchi fermentation characteristics.

Alcohol oxidation activities and optimization of extraction conditions of Rrhus verniciflua Stokes (RVS) extract were evaluated for the development of a functional biomaterial for improving liver function. When alcohol oxidation activities of RVS was analyzed, the Rrhus verniciflua Stokes bark (RVSB) were higher than the Rrhus verniciflua Stokes heartwood (RVSH). Alcohol oxidation activity value of RVSB increased in a concentrationdependent manner. In the comparative analysis between Hovenia dulcis Thunb (HDT) and Alnus japonica Steud (AJS) which was reported as a alcohol oxidation material, alcohol oxidation activity is much higher than the others. The experimental conditions were optimized for alcohol oxidation-active components production from RVSB. The extraction conditions such as temperature, time, pH and particle size were performed. It was recommended to extract the alcohol oxidation-active components from RVSB by hot water (pH 7.0) at 85℃ for 8 hours.

In achieving carbon neutrality and the hydrogen economy, the estimation of H₂ cost is critical in terms of CCU technologies. This study analyzes LCOH of hydrogen produced by the carbon utilization unit with methane reforming and CO₂ from thermal power plant. LCOH for H₂ made with CO is estimated in three ways of Joint Cost Allocations with financial performance risk assessment. Regarding cost analysis, the zero value of LCOH is $6,003/ton. We found that the CCU technology has economic feasibility in terms of profitability. The sensitivity analysis result shows that the input ratio is more influential to the LCOH than other variables. Risk analysis presents the baseline price of zero value of LCOH - $8,408/ton, which is higher than the cost analysis - $6,003/ton. Mainly, the price variability of natural gas primarily affects the LCOH. The study has significant value in analyzing the financial performance risks as well as the cost of H₂ produced by a Plasma-based CCU system.

This study investigated the relationships among 'integrative creativity', 'creativity in scientific humor', and 'perceptions of educational benefits for making scientific humor' of elementary students. To do this, five graders (n=42) at an elementary school and five graders (n=38) at a gifted science education institutes in Seoul were selected. Tests for 'integrative creativity', 'creativity in scientific humor', and 'perceptions of educational benefits for making scientific humor' were then administered. Analysis of the results revealed that the scores for some subcategories of 'creativity in scientific humor' were positively correlated with those for 'integrative creativity', especially for 'creative motivation (e.g., curiosity and playfulness)' and 'creative potency (e.g., knowledge, imagination, sensitivity, flexibility, and fluency)' more than 'creative attitude'. The subcategories of 'integrated creativity' that were significantly related to 'creativity in scientific humor' were somewhat different according to the subcategories of 'creativity in scientific humor'. The scores for all subcategories of 'perception of educational benefits for making scientific humor' were not significantly correlated with those for almost all subcategories of 'integrative creativity' and 'creativity in scientific humor'. Educational implications of these findings are discussed.

This study focuses on the performance of hydrogen energy based hybrid system in terms of system reliability of electricity generation. With this aim to evaluate the off-grid system of photovoltaic (PV), wind turbine, electrolyzer, fuelcell, $H_2$ tank and storage batteries, 14 different sites in South Korea are simulated using HOMER. Performance analysis includes simulation on the different sites, verification of operational behaviors on regional and seasonal basis, and comparison among a control group. The result shows that the generation performance of hydrogen powered fuelcell is greatly affected by geographical change rather than seasonal effect. In addition, as the latitude of the hybrid systems location decrease, renewable power output and penetration ratio (%) increase under constant electrical load. Therefore, the hydrogen based hybrid system creates the stability of electricity generation, which best suits in the southern part of South Korea.

A fuel cell electric vehicle (FCEV) could be an alternative solution to gasoline powered vehicles. The Korean and Japanese governments have played the midwifery role in the development of the FCEV industry. This study explores the difference in policy goals for FCEV between the two countries. Koreans recognized that FCEV was innovative technology and put forward the notion of technology pre-occupancy. Whereas, the Japanese government discovered that FCEV was one way to apply hydrogen mechanisms, so they identified the supply of hydrogen as one of the industries of interest, and have played the demiurge role. This study suggests that the role of government is to introduce eco-friendly vehicles, using the cases of Korean and Japanese governments, who introduced FCEV to the world first.

스피루리나를 세포벽 가수분해효소와 단백질 가수분해효소로 처리하여 조제한 스피루리나 가수분해물(enzymatic hydrolysate of spirulina, EHS)의 생리활성을 조사하였다. 효소처리 가수분해물의 유산균 증식효과, 항산화능, 암세포 증식저해 활성, 항혈전 활성을 분석한 결과 EHS는 유산균 증식활성과 항산화능에 큰 영향을 미치지 않았으며, 자궁경부암세포(HeLa)에 대해 1.42 mg/L의 농도에서 15% 미만의 증식저해효과를 나타내었다. 반면 항혈전 활성을 공통 경로(common pathway), 내인성 경로(intrinsic pathway), 외인성 경로(extrinsic pathway)로 구분하여 측정한 결과, 공통경로, 내인성 경로와 유사한 항혈전 활성이 있음을 확인하였다. 공통 경로를 thrombin time assay로 측정한 결과 EHS의 농도가 100 mg/L일 때 155.6초를 나타내었다. 내인성 경로는 activated partial thromboplastin time assay로 측정하였고, EHS의 농도가 1000 mg/L일 때 95.8초를 나타내었다. 외인성 경로를 prothrombin time assay로 측정한 결과 EHS의 농도가 1000 mg/L일 때 10.6초를 나타내었다. 결과적으로 스피루리나 효소가수분해물(EHS)이 항혈전경로 중 공통경로와 내인성 경로에 활성이 있음을 알 수 있었으며, 이를 토대로 신규의 항혈전 기능성 원료로 개발될 수 있을 것으로기대된다.

Biological activities of enzymatic hydrolysate of spirulina (EHS) were investigated. EHS showed no significant effects on the growth-stimulating activity for lactic-acid bacteria and antioxidant activity. EHS showed slight in vitro growth-inhibitory effects (15% at 1.42 mg/L) on a human cervical cancer cell line (HeLa). In addition, the anticoagulant activities of EHS were measured based on three different pathways: common, intrinsic and extrinsic pathways. As an indication of anticoagulant activity on common pathway, thrombin time (TT) of EHS (100 mg/L) was measured as 155.6 sec. Activated partial thromboplastin time (aPTT) for intrinsic pathway of EHS (1,000 mg/L) was measured as 95.8 sec. Prothrombin time (PT) based on extrinsic pathway of EHS (1,000 mg/L) was measured as 10.6 sec. These data showed that EHS have influences on anticoagulant factors of common pathway and intrinsic pathway. Consequently it was found that EHS could be used as a functional food for blood circulation.

Recently, most tech-based products are of multiple generations, since new-generation products are replacing the older ones as technologies continue to improve. Although, this means that research is needed to examine as much about the role of post-adoption behavior as the missing link between the adoptions of successive generation as first adoption of innovation, there is a dearth of literature explicitly examining consumers' post-adoption behavior, especially in the context of subscription-based service. For the subscription-based services, in spite of the important role of consumer satisfaction, research on the post-adoption behavior can not carefully examine the direct impact of consumer satisfaction on their decision to upgrade by considering usage instead of satisfaction as the missing link between buyers' first adoption and their next-generation adoption. This study identified two types of attribute satisfaction such as basic attribute and core attribute using both literature review and FGI (Focus Group Interview), and tries to investigate how two types of attribute satisfaction has influence on customers' intention to upgrade to the next-generation services. and a moderating role of customer loyalty between attribute satisfaction and intention. The empirical results show that core-attribute satisfaction has a negative influence on customers' intention to upgrade, due to the moderating role of customer loyalty, but it can raise their intention to upgrade next-generation services. However, basic-attribute satisfaction, on the other hand, appears to positively influence both customer loyalty and the intention to upgrade. We also find that the consumer attribute satisfaction is influenced by consumer innovativeness, her perception of service and the usage of each features' type in different ways. Finally, academic and practical implication is made, limitation is clarified and a direction for further studies is suggested.

폐기물로 버려지는 식품가공 부산물의 부가가치를 높여 포도 유래 기능성 소재를 생산하기 위한 목적으로 포도 송이가지로부터 레스베라트롤의 추출 조건을 최적화하였고 포도 송이가지 추출물(grape fruit stem extract, GFSE)의 생리활성을 평가하였다. 총 폴리페놀 및 레스베라트롤의 추출 조건으로서 추출 용매(메탄올과 에탄올), 시료와 용매의 처리 비율(w/v), 추출 온도 및 추출 시간이 레스베라트롤 추출 수율에 미치는 영향을 실험적으로 검토하고 통계프로그램을 이용하여 유의성을 평가하였다. 포도 송이가지로부터의 레스베라트롤 추출 조건을 최적화 한 결과, 80%의 에탄올에서 1:lO(w/v)의 용매의 비로 $60^{\circ}C$에서 90분을 추출하는 것이 가장 높은 추출수율을 나타냈다. 또한 포도 송이가지 추출물(GFSE)과 다른 항산화 물질의 생리활성 비교분석을 실시하였다. DPPH법에 의한 전지공여능과 SOD 유사활성으로 측정한 항산화 활성분석결과, 포도 송이가지 추출물은 비교물질로 사용된 항산화 물질들에 비해 높은 항산화능을 보였다. 결과적으로 본 연구에서 제조된 포도 송이가지 추출물은 항산화능이 높은 건강기능식품 및 화장품 소재로 주목받고 있는 레스베라트롤 소재로서 사용할 수 있음을 확인하였다.

The extraction conditions for resveratrol production from grape fruit stem, which is a by-product of grape processing, were optimized to develop high-functional grape-based products. Additionally, the bioefficacy of grape fruit stem extract (GFSE) as an antioxidant agent was evaluated. Resveratrol was extracted using various experimental conditions such as extractant type, extractant concentration, raw material-extractant ratio, extraction time and temperature, and the results were analyzed using a statistical program (SPSS). The resveratrol yield was the highest when 80% ethanol with a raw-material-extractant ratio of 1:10 (w/v) was used. In addition, the optimal temperature and time were selected as $60^{\circ}C$ and 90 min, respectively. When the antioxidant activity was analyzed and expressed as DPPH radical scavenging activity and SOD-like activity, the antioxidant activity of GFSE was higher than that of BHT, BHA and L-ascorbic acid. Finally, it was found that GFSE could be used as a raw material for the production of high antioxidant agents.

In this study a purified protein was prepared from pork meat. The product consisted of 0.5% moisture, 3.0% ash, 5.5% ether extract and 88.7% crude protein. Also, a meat oligopeptide mixture was prepared from a pepsin digest of the protein preparation. The two preparations were colorless and odorless powders with low fat contents. The nutritive values of the pork meat protein and oligopeptide mixture were estimated by two methods, one using biological value(BV) and the other employing net protein utilization(NPU) by the nitrogen balance method. The meat oligopeptide mixture showed an excellent nutritive value by both methods. The true digestibilites of both the pork meat protein and the oligopeptide mixture were more than 98%. The above results indicate that the oligopeptide mixture is an excellent material as a dietary nitrogen source for many purposes.

Owing to handset subsidies, large growth in the Korean mobile telephony subscribers has occurred. While most of firms create artificial switching costs by rewarding customers for repeated purchases to retain their customers, mobile telephone carriers discriminate against loyal customers through handset subsidies. This article examines the effect of switching cost on the prices and profits in a two-period, differentiated product duopoly model.