• 한국게임학회 논문지
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• 제18권5호
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• pp.23-30
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• 2018

ICT기술의 발달과 함께 게임 산업은 급속도로 성장하고 있다. 하지만 게임의 과도한 플레이로 인하여 정상적인 생활이 어려운 사례가 등장하고 있다. 이러한 게임 과몰입에 대한 진단과 대응 방안의 연구가 필요한 실정이다. 본 연구는 게임 이용자의 게임 이용 정보를 기반으로 게임 과몰입을 진단하는 시스템을 제안한다. 과몰입 진단 시스템을 개발하기 위하여 과몰입 및 선용 이용자를 분류하고, 실제 게임 환경에서 로그 정보를 수집하여 모델링하였다. 게임 이용자의 과몰입 및 선용군 모델은 새로운 게임 이용자의 과몰입 유무를 진단할 수 있는 지식으로 활용하였다. 실험을 통하여 의미있는 결과를 확인할 수 있었으며, 진단 결과에 따라 문자서비스, 리포팅 등의 서비스 방안도 제시하였다.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.997-1003
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• 2008

Viral safety is a prerequisite for manufacturing clinical antihemophilic factor VIII concentrates from human plasma. With particular regard to the hepatitis A virus (HAV), a terminal dry-heat treatment ($100^{\circ}C$ for 30 min) process, following lyophilization, was developed to improve the virus safety of a solvent/detergent-treated antihemophilic factor VIII concentrate. The loss of factor VIII activity during dry-heat treatment was of about 5%. No substantial changes were observed in the physical and biochemical characteristics of the dry-heat-treated factor VIII compared with those of the factor VIII before dry-heat treatment. The dry-heat-treated factor VIII was stable for up to 24 months at $4^{\circ}C$. The dry-heat treatment after lyophilization was an effective process for inactivating viruses. The HAV, murine encephalomyocarditis virus (EMCV), and human immunodeficiency virus (HIV) were completely inactivated to below detectable levels within 10 min of the dry-heat treatment. Bovine herpes virus (BHV) and bovine viral diarrhea virus (BVDV) were potentially sensitive to the treatment. However porcine parvovirus (PPV) was slightly resistant to the treatment. The log reduction factors achieved during lyophilization and dry-heat treatment were ${\geq}5.55$ for HAV, ${\geq}5.87$ for EMCV, ${\geq}5.15$ for HIV, 6.13 for BHV, 4.46 for BVDV, and 1.90 for PPV. These results indicate that dry-heat treatment improves the virus safety of factor VIII concentrates, without destroying the activity. Moreover, the treatment represents an effective measure for the inactivation of non-lipid-enveloped viruses, in particular HAV, which is resistant to solvent/detergent treatment.

• Parasites, Hosts and Diseases
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• 제36권3호
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• pp.203-206
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• 1998

닭에 있어서 닭와포자충 감염이 다른 중요 가금 질병에 대한 체액성 면역억제 현상을 규명하기 위해 2일령의 보통 병아리에 $2{\;}{\times}{\;}10^6$의 닭와포자충 난포낭을 한번에 경구 투여한 다음 4일과 14 일 두 번에 걸쳐 닭전염성기관지염 생독백신을 접종하여 1주 간격으로 혈구응집억제반응으로 항체 가를 측정하였다 감염 및 비감염군 모두 평균 항체가는 점점 낮아져 2차 예방접종 후 2주에 최저 에 이른 다음 점점 높아져 일정한 수준을 유지하였다. 일반적으로 평균 항체가는 비감염군에 비하 여 감염군이 의의있게 낮았다 (p<0.05). 한편, 이 두 병원체를 접종하지 않은 진정 대조군의 1일 령의 모체이행항체가 $log_2{\;}5.16{\;}{\pm}{\;}1.39$는 시간이 경과함에 따라 점점 낮아져 6주령에 이르러 완 전히 음전하였다. 이는 직선적인 변화를 하였으며, 주를 함수 (X)로 한 Y = -0.90X + 4.67의 일차방정식에 잘 부합하였으며, 실측치와 추정치와의 상관계수는 R = 0.9454이었다. 닭와포자충 감염 병아리는 건강한 것에 비하여 닭전염성기관지염 바이러스에 대한 면역억제현상이 일어나 아마도 감수성이 증가할 것으로 생각된다.

• 한국식품과학회지
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• 제28권1호
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• pp.105-108
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• 1996

초고압처리한 신선초 녹즙을 $4^{\circ}C$에서 냉장보관 하면서 미생물의 변화 및 관능적 특성의 변화를 살펴보았다. 초고압처리는 전보에서 최적살균조건으로 계산된 $5700\;kg_f/cm^2$, 7 min의 조건으로 처리하였는데 초기 $8.7{\times}10^6\;CFU/mL$ 존재하던 일반 세균수가 초고압처리 후에는 $3.2{\times}10^3\;CFU/mL$로 감소하여 전보에서 계산된 예상 살균치인 3.44 log cycle 감소에 잘 부합하였다. 특히, 저온저장 식품에 문제가 되는 녹농균이 완전히 사멸하였으므로 저온저장에 유리한 특성을 부여하리라 생각되었다. 대장균 및 대장균군도 완전히 사멸되었다. 관능검사 결과, 밝기와 풀냄새를 제외하고는 초고압처리에 의해 관능특성상의 유의적 차이가 생기지 않았으며, $4^{\circ}C$에서 8일간 저장한 후에는 신선감에서 초고압처리한 녹즙이 유의적으로 높은 점수를 얻었다. 하지만 초고압처리 녹즙에서도 효소적 갈색화로 인한 색도의 변화가 일어나 해결해야 할 문제점으로 부각되었다.

• 한국식품영양과학회지
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• 제30권5호
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• pp.834-838
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• 2001

칼슘함량이 높은 녹미채를 넣은 김치를 만들고 1$0^{\circ}C$에서 숙성하면서 pH, 적정산도, 환원당, 총균수, 유산균수 및 관능 검사를 실시한 결과는 다음과 같았다. 녹미채의 첨가량이 많을수록 pH가 높은 것은 김치의 숙성 5일에서 15일 사이였으며, 그 이후로는 시험구간에 차이가 크지 않았다. 녹미채를 첨가한 김치의 적정산도는 대조구보다 낮았으며, 0.1%를 첨가한 시험구가 가장 낮은 값을 보였다. 김치의 적숙기로 생각하는 적정산도 0.6~0.8%를 기준으로 본다면 0.1% 첨가구는 2~3일 정도 적숙기를 연장하는 효과가 있을 것이다. 또한 이 시험구는 숙성 10일부터 다른 시험구에 비하여 높은 환원당 함량을 유지하였는데, 이는 적정산도의 증가가 다른 시험구에 비하여 낮았기 때문으로 보인다. 김치를 담근 직후부터 숙성 2일째까지 녹미채를 첨가한 김치의 유산균수가 대조구에 비하여 현저히 낮았으나 10일 이후에는 큰 차이를 보이지는 않았다. 숙성 5일째인 김치의 색, 냄새 및 맛을 평가한 결과 대조구가 가장 높은 점수를 얻었으며, 녹미채를 0.1% 첨가한 시험구는 대조구보다 점수는 낮았으나 유의적인 차이는 없었다.

• 한국식품영양학회지
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• 제32권5호
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• pp.494-503
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• 2019

The purpose of this study was to investigate the quality and antioxidant properties of three fermented sweet potato cultivars (Shinyulmi, Hogammi, and Shinjami) using lactic acid bacteria. During the fermentation, the pH was lowered and the titratable acidity increased. The viable cell counts of lactic acid bacteria increased 8.44-9.62 log CFU/g. Organic acid content (especially lactic acid) of sweet potatoes increased by fermentation. Also, ${\gamma}$-Aminobutyric acid increased more than 8.6 times by fermentation in all samples. The total polyphenol and flavonoid contents of sweet potato, showed insignificant changes in all samples by fermentation. ABTS radical scavenging activity of all samples slightly decreased by fermentation, but not significantly. DPPH radical scavenging activity decreased slightly by fermentation except Shinyulmi. However, when compared with the varieties, Shinjami showed the highest activity. The reducing power of Shinjami decreased slightly by fermentation, but activity was the highest among all samples. Based on these results, most of the chemical properties and functionality of fermented sweet potato are retained after fermentation, although some antioxidant activity decreases. We suggest that three fermented sweet potato cultivars (Shinyulmi, Hogammi, and Shinjami) using lactic acid bacteria can be used in various applications because of their effective functional properties.

• 대한영양사협회학술지
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• 제25권1호
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• pp.30-43
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• 2019

This study compared the predictive models for the growth kinetics of Staphylococcus aureus in ham rice balls. In addition, a semi-quantitative risk assessment of S. aureus on ham rice balls was conducted using FDA-iRISK 4.0. The rice was rounded with chopped ham, which was mixed with mayonnaise (SHM), soy sauce (SHS), or gochujang (SHG), and was contaminated artificially with approximately $2.5{\log}\;CFU{\cdot}g^{-1}$ of S. aureus. The inoculated rice balls were then stored at $7^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$, and the number of viable S. aureus was counted. The lag phases duration (LPD) and maximum specific growth rate (SGR) were calculated using a Baranyi model as a primary model. The growth parameters were analyzed using the polynomial equation as a function of temperature. The LPD values of S. aureus decreased with increasing temperature in SHS and SHG. On the other hand, those in SHM did not show any trend with increasing temperature. The SGR positively correlated with temperature. Equations for LPD and SGR were developed and validated using $R^2$ values, which ranged from 0.9929 to 0.9999. In addition, the total DALYs (disability adjusted life years) per year in the ham rice balls with soy sauce and gochujang was greater than mayonnaise. These results could be used to calculate the expected number of illnesses, and set the hazard management method taking the DALY value for public health into account.

• 한국축산식품학회지
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• 제39권1호
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• pp.139-150
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• 2019

This study aimed to determine the suitable point of sale and consumption of different quality grade (QG) Hanwoo short loin during aging period, based on physicochemical, sensory, and microbiological quality. Short loins obtained from the carcasses of 13 Hanwoo steers and 2 bulls with 5 different QGs (1++, 1+, 1, 2, and 3) were analyzed over 28 d. QG and aging time had significant effect on water holding capacity, color, shear force, total volatile basic nitrogen (TVBN) content, and sensory traits. Higher QG groups generally exhibited a lower shear force, nucleotide content, and water holding capacity, and higher $L^*$, $a^*$, and $b^*$ values. Acceptable tenderness (shear force <5.4 kg) in QG 1++, 1+, 1, and 2 was achieved on days 7, 14, 16, and 18, respectively, and QG 3 showed a shear force of 6.8 kg, even after 28 d. Regardless of QG, TVBN content below threshold levels (20-30 mg%) was observed throughout the 28 d aging period, while total plate counts above 7 Log CFU/g were seen at 21 d. In conclusion, it is recommended that Hanwoo beef with QG 1++, 1+, and intermediate QG (1 and 2) should be sold or consumed between 7 and 21, 14 and 21, 16 and 21 d, respectively. Beef with QG 3 should be sold or consumed within 21 d, based on microbial growth, even though it has not achieved desirable tenderness. For this reason, an additional tenderizing process is recommended before this beef is ready for consumption.

• 한국축산식품학회지
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• 제39권3호
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• pp.510-519
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• 2019

The effect of combined electron-beam irradiation and aging temperature of pork on microbiological and physicochemical properties was investigated. The samples from pork shoulder were irradiated with 0 or 2 kGy, vacuum-packaged, and assigned randomly to an aging temperature ($2^{\circ}C$, $10^{\circ}C$, or $25^{\circ}C$) during 8 d. On 4 d of aging at $25^{\circ}C$, total aerobic bacteria of non-irradiated ones reached 7 Log CFU/g which is no salable levels. Shear force values of irradiated meat after aging for 2 and 4 d at $25^{\circ}C$ was lower than those aged at $2^{\circ}C$. Irradiated samples at $2^{\circ}C$ had lower cooking loss after 2 and 8 d of aging, compared with other aging temperatures. Irradiation did not accelerate 2-thiobarbituric acid reactive substance (TBARS) value when aged up to 4 d. Irradiated samples aged at $10^{\circ}C$ and $25^{\circ}C$ for 8 d scored significantly higher TBARS values. With an increased aging period, $a^*$ and $b^*$ in irradiated samples at $2^{\circ}C$ slightly increased, but irradiation caused negligible changes in meat color. The highest contents of a desirable nucleotide flavor compounds (inosine-5-phosphate) were observed in pork at $2^{\circ}C$ when aged for 4 and 8 d, while the lowest contents were observed at $25^{\circ}C$. Aging in irradiated pork for 8 d at $2^{\circ}C$ resulted in optimal condition with improved meat quality and minimal microbiologically negative defect.

• Fisheries and Aquatic Sciences
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• 제25권9호
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• pp.463-472
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• 2022

In this study, a microbial risk assessment was performed for the bacteria Vibrio parahaemolyticus, which causes a foodborne illness following the consumption of Jeotgal, a fermented seafood in South Korea. The assessment comprised of six stages: product, market, home, consumption, dose-response, and risk. The initial contamination level (IC) was calculated based on the prevalence of V. parahaemolyticus in 90 Jeotgal samples. The kinetic behavior of V. parahaemolyticus was described using predictive models. The data on transportation conditions from manufacturer to market and home were collected through personal communication and from previous studies. Data for the Jeotgal consumption status were obtained, and an appropriate probability distribution was established. The simulation models responding to the scenario were analyzed using the @RISK program. The IC of V. parahaemolyticus was estimated using beta distribution [Beta (1, 91)]. The cell counts during transportation were estimated using Weibull and polynomial models [δ = 1 / (0.0718 - 0.0097 × T + 0.0005 × T²)], while the probability distributions for time and temperature were estimated using Pert, Weibull, Uniform, and LogLogistic distributions. Daily average consumption amounts were assessed using the Pareto distribution [0.60284,1.32,Risk Truncate(0,155)]. The results indicated that the risk of V. parahaemolyticus infection through Jeotgal consumption is low in South Korea.