For a plastic diffusion lens to uniformly diffuse light, it is important to minimize deformation that may occur during injection molding and to minimize deformation. It is essential to control the injection molding condition precisely. In addition, as the number of meshes increases, there is a limitation in that the time required for analysis increases. Therefore, We applied machine learning algorithms for faster and more precise control of molding conditions. This study attempts to predict the deformation of a plastic diffusion lens using the Decision Tree regression algorithm. As the variables of injection molding, melt temperature, packing pressure, packing time, and ram speed were set as variables, and the dependent variable was set as the deformation value. A total of 256 injection molding analyses were conducted. We evaluated the prediction model's performance after learning the Decision Tree regression model based on the result data of 256 injection molding analyses. In addition, We confirmed the prediction model's reliability by comparing the injection molding analysis results.

이산화탄소 배출이 없는 고분자 전해질 막 연료전지(polymer electrolyte membrane fuel cell, PEMFC)는 수송용, 발전용 시스템에 적용 가능한 친환경 에너지 변환장치이다. PEMFC의 주요 구성품 중 하나인 고분자 전해질 막(polymer electrolyte membrane, PEM)은 구동시간 동안의 높은 수소 이온 전도도와 물리화학적 안정성 갖춘 과불소화계 고분자 (perfluorinated sulfonic acid, PFSA) 기반 PEM (PFSA-PEM)이 상용화 되어있다. 하지만 PFSA-PEM의 단점으로 지적되는 낮은 유리전이온도와 높은 기체 투과도의 보완이 요구되고 있다. 이에 본 총설에서는 PFSA-PEM의 성능 향상 및 단점 보완 을 위해 1) PFSA의 측쇄부 길이를 조절함으로써 이온교환용량의 증가와 고분자의 결정성을 증가시켜 PFSA-PEM의 능력을 향상시킨 연구와 2) 유/무기 첨가제를 도입하여 수소 이온 전도도 및 물리적 안정성을 향상시키는 복합 막 연구 및 3) 다공성 지지체를 도입하여 PEM의 두께를 효과적으로 감소시켜 막 저항을 효과적으로 줄이고 내구성을 큰 폭으로 개선한 다공-충진 막에 관한 연구를 소개하고자 한다.

This study examined the certification effects of safety and health management system (SHMS) on the establishment level of SHMS and accident statistics in construction industry. This study obtained the establishment level of SHMS for 106 construction companies surveyed from our previous study. In addition, three major accident statistics (mortality rate, accidental mortality rate, and injury rate) for the companies were collected from the database in Korean Occupational Safety and Health Agency. The statistical analysis results revealed that the establishment level for SHMS certified companies was significantly higher than those for uncertified or certification preparing companies. Furthermore, SHMS certified companies showed significantly smaller accident statistics compared to uncertified or certification preparing companies. The results of this study support the positive effects of SHMS on reducing major industrial accidents in construction companies.

시판 유통 중인 건조 인삼류(백삼 24점, 홍삼 26점) 포 장 제품을 수집하여 곰팡이 발생 조사를 수행하였다. 백 삼과 홍삼은 각각 50%와 46%의 시료에서 곰팡이가 검출 되었고 검출 시료의 평균 곰팡이 오염도는 각각 0.5와 0.2 log10 CFU/g이었다. 백삼에서는 Penicillium polonicum, P. chrysogenum, Rhizopus microsporus가 각각 18.2%로 우점하 였으나 홍삼은 Aspergillus spp.이 87.6%로 우점하였으며 이 중 A. chevalieri가 50.0%로 가장 높았다. 이 중 독성 종으로 알려진 P. polonicum, P. chrysogenum, P. melanoconidium, A. chevalieri 균주의 citrinin 독소 생성 가능성을 분석한 결 과, 13 균주 모두 독소 유전자가 검출되지 않았다. 이 결 과는 조사한 시료의 곰팡이독소 오염 위험은 매우 낮지만, 건조 인삼류에 곰팡이 오염이 가능함을 보여준다.

진해만 해역은 태풍 내습 시에 우리나라 남동권 해역의 주요 태풍 피항지로 이용되고 있다. 하지만 태풍 내습 시 진해만 내 선박이 폭주하고 주묘가 다수 발생하는 등 해양사고 발생 가능성이 존재한다. 본 논문은 태풍 내습 시 진해만 피항지에 대해 안전 확보 및 효율적으로 관리할 수 있는 방안을 해당 해역의 VTS 관제사로부터 도출하고, 이를 선박 운항자에게 AHP 기법을 통하여 상대적 중요 도를 도출하여 관리자와 이용자 의견이 반영된 안전대책을 제시하였다. AHP 설문조사를 위한 안전 대책 요소를 선정하기 위하여 진해만 내 태풍 내습 시 VTS 관제사의 대응 조치 평가 내용에 대해 분석하였다. 선정된 안전대책 요소를 기반으로 설문조사를 실시한 결과, 선정 된 요소에 대해 선박 운항자는 선박의 안전을 효율적 관리보다 약 2배 이상 중요하게 생각하며, 종합적으로 피항선 관리, 정박구역 관리, 피항정보 관리, 규정 및 지침 마련, 시스템 장비 개선, 교육 및 홍보·알림 활동 순으로 중요하게 고려함을 파악하였다. 본 논문에서 식별된 방안 및 상대적 중요도를 통해서 진해만 태풍 피항지를 안전하고 효율적으로 관리하는 기반이 될 수 있을 것으로 사료된다.

The consumption of Flammulina velutipes mushroom imported from Korea has been associated with the cases of listeriosis in the United States, Canada, and Australia. We investigated the effect of sanitizing the plastic wrapper (used in packaging F. velutipes) with slightly acidic electrolyzed water (SAEW) and ultraviolet C waterproof light-emitting diode (UVC-WLED) on reducing the Listeria monocytogenes. Further, the effect of UVC-LED on L. monocytogenes growth in F. velutipes at different storage temperatures (2, 4, and 10oC) was determined. The combined (SAEW+UVC-W-LED) treatment for 5–10 min reduced 99.9% of bacterial population from the contaminated plastic wrapper. In addition, the UVC-LED treatment for 3 min reduced the L. monocytogenes concentration in F. velutipes by 0.47 log CFU/g. Moreover, the growth of L. monocytogenes in the treated mushrooms was slower than that of the untreated (control) ones. L. monocytogenes concentration in F. velutipes increased over 3 log CFU/g at 2oC and 10oC for 60 and 10 days, respectively. The growth of L. monocytogenes at the bottom of mushrooms was faster than that at the top at both the temperatures. These results indicate that the combined SAEW+UVC-WLED treatment of plastic wrappers and the UVC-LED treatment of mushrooms can be used as potential hurdle technologies to control the risk of L. monocytogenes in mushrooms prior to packaging at farms.

Probiotic strain is known to regulate the immune system by colonizing in the intestine and interact with intestinal cell receptors of lymphoid tissue. In this study, safety of Streptococcus thermophilus KCTC14471BP and silk fibroin coating effects was evaluated with respect to mucin binding abilities and immune system modulation. S. thermophilus KCTC14471BP was coated with silk fibroin by adding 1% water-soluble calcium and 0.1% silk fibroin. S. thermophilus KCTC14471BP showed the high activities of leucine arylamidase and β-galactosidase. Regarding the antibiotic resistance tests, S. thermophilus KCTC14471BP was susceptible to ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, and chloramphenicol. S. thermophilus KCTC14471BP coated with silk fibroin showed the improved mucin binding ability from 16.1% to 71.3% and was confirmed to have no cytotoxicity against RAW 264.7 macrophage. S. thermophilus KCTC14471BP coated with silk fibroin showed dose-dependently significant increases in pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. These results suggested that S. thermophilus KCTC14471BP can be expected as a promising probiotic bacteria for applications to food industries such as fermentation or functional foods.

This mini-review focused on the current advances in the development and the application of the antibacterial agents produced from probiotics strains against foodborne pathogens. Inhibitory activity of the pathogen growth could be achieved by co-culture with probiotics and/or the treatment of metabolites extracted from probiotics culture, whereas strain-dependent efficacy was mainly reported according to the bacterial species of the target pathogens. To overcome the limited antibacterial spectrum and the efficacy of the metabolites from probiotics, the recent research highlight the discovery of novel bioactive substances with broad range of the inhibitory activity of foodborne pathogens and mode-of-action which has not been reported as the major research goal. Moreover, understanding the distribution of functional and regulation genes coding the production of the antibacterial metabolites based on the bacterial genome analysis can provide the clues for the mechanisms of the pathogen control by using probiotics. Major strategies on the application of the genomics in this research area can be represented as follows: 1) functional annotation specialized for antimicrobial proteins, 2) assessment of the antibacterial effects followed by the general/functional annotation, 3) genome and metabolites analysis for the purification of antimicrobial proteins, 4) comparative genomics and the characterization of antimicrobial potential. Especially the relationship between phenotype-genotype based on genomic bioinformation with the results of the practical efficacy tests of bacterial metabolites as an active substance of disinfectants and/or preservatives can be expected to act as supportive research for broadening our knowledge regarding the key metabolic pathways associated with the production of antibacterials from probiotics.