Nowadays, artificial intelligence model approaches such as machine and deep learning have been widely used to predict variations of water quality in various freshwater bodies. In particular, many researchers have tried to predict the occurrence of cyanobacterial blooms in inland water, which pose a threat to human health and aquatic ecosystems. Therefore, the objective of this study were to: 1) review studies on the application of machine learning models for predicting the occurrence of cyanobacterial blooms and its metabolites and 2) prospect for future study on the prediction of cyanobacteria by machine learning models including deep learning. In this study, a systematic literature search and review were conducted using SCOPUS, which is Elsevier’s abstract and citation database. The key results showed that deep learning models were usually used to predict cyanobacterial cells, while machine learning models focused on predicting cyanobacterial metabolites such as concentrations of microcystin, geosmin, and 2-methylisoborneol (2-MIB) in reservoirs. There was a distinct difference in the use of input variables to predict cyanobacterial cells and metabolites. The application of deep learning models through the construction of big data may be encouraged to build accurate models to predict cyanobacterial metabolites.

Benthic attached diatoms (BADs), a major primary producer in lotic stream and river ecosystems are micro-sized organisms and require a highly magnified microscopic technique in the observation work. Thus, it is often not easy to ensure accuracy and precision in both qualitative and quantitative analyses. This study proposed a new technique applicable to improve quality control of aquatic ecosystem monitoring and assessment using BADs. In order to meet the purpose of quality control, we developed a permanent mounting slide technique which can be used for both qualitative and quantitative analyses simultaneously. We designed specimens with the combination of grid on both cover and slide glasses and compared their efficiency. As a result of observation and counting of BADs, the slide glass designed with the color-lined grid showed the highest efficiency compared to other test conditions. We expect that the method developed in this study could be effectively used to analyze BADs and contributed to improve the quality control in aquatic ecosystem health monitoring and assessment.

The objective of this study was to achieve biological control of green mold disease in Pyogo mushrooms using antagonistic microorganisms. Bacillus subtilis BSM320 cells inhibited mycelial growth by 48–60% against three Trichodermaisolates including T. hazianumisolated from the substrates of Lentinula edodes, showing their antifungal activity.The bacteria were cultured to a high density of 4.2 x 109±113.7 cfu/mlin aqueous extract of composted spent mushroom substrates of L. edodes containing 1% glucose and showed a higher growth rate than that observed when using the commercial medium, Luria-Bertani broth. The bacterial culture showed a 75% protective effect without damaging the mushroom fruiting bodies. These results suggest that B. subtilis BSM320culture is suitable for biological control of green mold disease during mushroom cultivation.

본 연구의 목적은 미국, 영국, 독일, 일본의 학교안전 법제를 살펴봄으로 써, 국내 학교안전에 시사하는 바를 논하고 제시하는 데에 있다. 외국사례를 통해 우리나라 학교안전사고 예방 및 학교안전관리시스템이 보다 실효성 있 게 작동하도록 몇 가지 적용 및 시사점을 제시하였다. 첫째, 학교 안전관리 책임을 명확히 하고 학교안전교육을 지원하는 법제의 명문화와 「학교폭력예 방법」, 「학교안전법」, 「학교보건법」을 「학교안전보건법」으로 통합할 필요가 있다. 둘째, 국가 책임을 강화하는 차원에서 충분한 예산 지원과 인력 확보 및 교직원의 안전 전문성 향상을 위한 제도 마련, 그리고 일원화된 전문기관 등이 필요하다. 셋째, 「학교안전법」을 「산업안전보건법」 수준으로 업그레이 드할 필요가 있고, 독일의 사회보험 수준으로 학교안전공제회의 역량을 제고 할 필요가 있다. 넷째, 체계적인 시스템과 실효성 있는 매뉴얼에 의해 작동되 도록 학교안전망을 촘촘하게 구축할 필요가 있다. 다섯째, 예방활동과 안전 교육의 패러다임을 전환할 필요가 있다. 여섯째, 평소 지역 유관기관·단체 등 과 안전시스템을 긴밀하게 공유, 연계할 필요가 있다. 일곱째, 실효성 있는 학교안전 위험성 평가를 실시하여 사고 발생률을 낮출 필요가 있다. 여덟째, 학교 보안을 더욱 강화할 필요가 있다. 아홉째, 학생안전 법제에 학생의 권리 와 의무를 함께 명시할 필요가 있다. 열 번째, 우리나라도 ‘갭 이어(Gap Ye ar)’ 제도 도입을 검토할 필요가 있다. 이상의 논의와 제시를 통해, 국내 학 교안전 및 학교안전 법제의 긍정적 변화를 기대한다.

In factory automation, efforts are being made to increase productivity while maintaining high-quality products. In this study, a CNN network structure was designed to quickly and accurately recognize a cigarette located in the opposite direction or a cigarette with a loose end in an automated facility rotating at high speed for cigarette production. Tobacco inspection requires a simple network structure and fast processing time and performance. The proposed network has an excellent accuracy of 96.33% and a short processing time of 0.527 msec, showing excellent performance in learning time and performance compared to other CNN networks, confirming its practicality. In addition, it was confirmed that efficient learning is possible by increasing a small number of image data through a rotation conversion method.

This study investigated the antioxidant characteristics of sweet potato according to different plant parts and drying methods. The sweet potato plant parts were divided into root tubers, stems, stalks, leaves, and tips, and the drying methods were freeze-drying and hot air drying. Total polyphenol and flavonoid contents and radical scavenging activity of the sweet potato plant parts were significantly different depending on the plant parts and drying methods. The total polyphenol content of freeze-dried sweet potato leaves and tips were 52.76 and 46.19 mg chlorogenic acid equivalents/g sample, and the total flavonoid contents were 222.47 and 214.12 mg quercetin equivalents/g sample, respectively, and decreased with hot air drying. DPPH radical scavenging activity was higher in freeze-drying than hot air drying and was significantly different depending on the plant parts. The ABTS radical scavenging activity of freeze-dried sweet potato leaves and tips were 43.48 and 44.68 mg Trolox equivalents/g sample, respectively, and decreased with hot air drying. Therefore, additional studies on the functionality of using by-products from sweet potato cultivation are needed.

The purpose of this study was to analyse factors related to Home Meal Replacement (HMR) use among university students and to determine the dietary quality according to its consumption. A survey on the consumption of HMR and Nutrition Quotient (NQ) was conducted from September to November 2021. The study included 232 university students (88 males, 144 females) from Chungcheong. The proportion of consumption at least once a week was 71.55% for ready-to-eat foods, 55.60% for ready-to-cook foods, 40.95% for fresh-cut products, and 21.12% for meal-kits. The preference ratings were as follows: ready-to-eat foods, 3.77 out of 5 points, meal-kits, 3.53 points, fresh-cut products, 3.52 points, and ready-to-cook foods, 3.45 points. In terms of satisfaction, convenience (4.06 out of 5 points), taste (3.71 points), variety (3.67 points), and food hygiene (3.62 points) were rated the highest. The scores in the moderation NQ were significantly lower in the groups that consumed ready-to-eat foods (p=0.0002), ready-to-cook foods (p=0.0002), and meal-kits (p=0.0068) at least once a week compared to the groups that consumed them less than once a week. In conclusion, the results will serve as basic data for nutrition education for proper consumption of HMR among university students.

This study developed and evaluated a load cell-based automatic weighing system for the automated harvesting of laver (Porphyra tenera) in seaweed aquaculture. The current manual harvesting process was compared with the load cell-based automated system, and quantitative measurements of time, distance, and weight were conducted. The results demonstrated that the load cell-based system reduced the unloading time and increased the throughput compared to the manual method. In addition, statistical analysis confirmed that there was no significant difference from the mean in the weight measurement obtained using the load cell-based system. Based on these findings, the load cell-based automatic weighing system holds potential for efficient production and transactions in laver cultivation, contributing to cost reduction and improving the quality of life for aquaculture workers.

주소 관련 미래 산업의 확장으로 새로운 주소체계에 대한 수요가 증가하였으며, 특정 사물에 주소를 부여하는 체계인 사물주소의 중요성이 강조되고 있다. 현행 사물주소는 행정안전부가 제작 및 배포하고 있으며 데이터베이스 제작 등 사물주소의 활성화를 위한 노력이 지속되고 있다. 하지만 현행 사물주소는 하향식 방법으로 부여되고 있기 때문에 수요자 응답형 정보제공 대응에 미흡한 현실이다. 이에 본 연구에서는 상향식 방법으로 운영 중인 포켓몬 고 DB와 사물주소 DB의 공간적 분포를 탐색함으로 써 사용자 참여형 주소정보 생성 및 적용 가능성을 제시하였다. 각 DB의 지점별 티센 폴리곤을 생성한 뒤 ANOVA 분석을 수행한 결과 두 DB간의 면적 차이가 있음을 확인하였다. 또한 지니 계수를 산출하여 분포 불평등성을 확인하여 DB를 통합하여 활용하는 방법을 제시하였다. 본 연구는 사물주소의 확산과 알기 쉬운 대국민 주소정보체계 확립에 정책적인 활용이 가능할 것이다.

본 연구는 감정노동자 심리분석을 통한 심리치유 방향에 대한 연구이다. 본 연구의 목적 은 감정노동 심리치유 프로그램 개발에 기여 하고자 한다. 본 연구의 대상은 G도 북부지역 감정노동자 157명을 대상으로 설문조사를 하였다. 연구 기간은 2021년 4월부터 2023년 2 월까지 진행되었다. 자료 분석은 SPSS 28.0 통계프로그램을 이용하여 일원분산분석 (One-way ANOVA) 및 피어슨의 상관관계 분석(pearson correlation analysis)을 하였다. 연 구결과는 직군별 감정노동 수준은 M 3.03∼3.96, 감정노동 인식은 M 2.40∼3.48 유의미한 차이가 없는 상태로 나타났다, 감정노동 실태 면에서 1직군(M 2.81), 2직군(M 2.88)은 다른 직군과 M 0.68∼0.4의 차이를 보이는 등 언어적 폭력에서 더 취약한 결과가 나타났다. 감정 노동의 수준 정도에 따라 감정 부조화 및 손상-고객 응대 부조화 및 갈등 순으로 직업 불 만족에 영향을 주고 있다는 유의미한 차이를 볼 수 있다. 정신적 평가결과에서도 감정노동 으로 인해 감정소진, 의욕 저하 등 심리적 문제가 발생하고 있음을 알 수 있다. 이를 통해 향후 감정노동자 심리치유 발전에 기여하고자 한다.

In this study, the quality safety limit period of seven types of bakery bread was analyzed, and their use-by date was calculated. For evaluating product quality, storage conditions were set as 5, 15, 25, and 35oC for 50 days, and moisture, microorganisms, sensory characteristics, and dominant bacteria were examined. The quality and safety standards followed the Korea Food Code and Korean industrial standards (KS). The results showed that all products stored at 5oC satisfied the standard for bacterial count for day 50, but the sensory quality was below the standard level. Samples stored at 15oC showed high variability from 3–39 days. At 25oC, a quality safety limit period of 2–20 days was set, and one sample was found to have the same shelf life. Bread stored at 35 °C had the shortest quality safety limit period. Considering a safety factor of 0.87, a use-by date period of 1.7–13.1 days was calculated. Therefore, setting the use-by date according to the product type is necessary, even for the same product category. Among the bread products sold in bakeries, those managed as room temperature products (1–35oC) can be distributed and stored in a temperature range of up to 35oC. Overall, this study demonstrates the importance of setting a quality retention period based on the product characteristics and carefully considering the safety factor.

The influence of specimen geometry and notch on the hydrogen embrittlement of an SA372 steel for pressure vessels was investigated in this study. A slow strain-rate tensile (SSRT) test after the electrochemical hydrogen charging method was conducted on four types of tensile specimens with different directions, shapes (plate, round), and notches. The plate-type specimen showed a significant decrease in hydrogen embrittlement resistance owing to its large surface-to-volume ratio, compared to the round-type specimen. It is well established that most of the hydrogen distributes over the specimen surface when it is electrochemically charged. For the round-type specimens, the notched specimen showed increased hydrogen susceptibility compared with the unnotched one. A notch causes stress concentration and thus generates lots of dislocations in the locally deformed regions during the SSRT test. The solute hydrogen weakens the interactions between these dislocations by promoting the shielding effect of stress fields, which is called hydrogen-enhanced localized plasticity mechanisms. These results provide crucial insights into the relationship between specimen geometry and hydrogen embrittlement resistance.

Porous ceramics are used in various industrial applications based on their physical properties, including isolation, storage, and thermal barrier properties. However, traditional manufacturing environments require additional steps to control artificial pores and limit deformities, because they rely on limited molding methods. To overcome this drawback, many studies have recently focused on fabricating porous structures using additive manufacturing techniques. In particular, the binder jet technology enables high porosity and various types of designs, and avoids the limitations of existing manufacturing processes. In this study, we investigated process optimization for manufacturing porous ceramic filters using the binder jet technology. In binder jet technology, the flowability of the powder used as the base material is an important factor, as well as compatibility with the binder in the process and for the final print. Flow agents and secondary binders were used to optimize the flowability and compatibility of the powders. In addition, the effects of the amount of added glass frit, and changes in sintering temperature on the microstructure, porosity and mechanical properties of the final printed product were investigated.

난치성 담관결석은 내시경 유두 괄약근 절개술 후 EPLBD, 기계적 쇄석술, 경구담관경 유도하 담관 내 전기수압쇄석술 혹은 레이저 쇄석술, 일시적 플라스틱 담관 스텐트 삽입, 경피경간담관경유도하 쇄석술, 체외충격파쇄석술 등 다양한 시술을 통해 해결될 수 있다. 본고에서는 가용 가능한 다양한 방법을 사용하여 난치성 총담관결석을 제거한 증례를 소개하고 각각의 과정에서의 시술의 어려움을 극복하는 대응방법을 논의하고자 하였다.

이 연구에서는 노년기 의미 있는 활동에 대한 중요도와 지식 정도의 요인을 분 석하기 위해 웰에이징 전문가 126명을 대상으로 자기기입식 설문을 실시하였다. 연구방법은 SPSS 통계프로그램을 이용하여 빈도분석 및 student t-test와 one-way ANOVA 및 Pearson 상관분석 실시하였으며, 노인의 의미 있는 활 동의 중요도 및 지식 정도는 IPA(Importance Performance Analysis) 분 석을 통해 경쟁우위 영역과 개선영역을 도출하였다. 연구결과 친구나 지인과 함 께하는 일(활동) 관련 프로그램은 중요도는 높으나 지식 정도가 낮아 중점 개선영역으로 나타났으며, 사회적 활동으로 유익한 시간을 보낼 수 있는 프로그램은 중요도와 지식 정도 모두 높아 경쟁우위 영역으로 나타났고, 혼자 하는 일(활동) 관련 프로그램은 지식 정도는 높으나 중요도가 낮아 우위 영 역으로 나타났으며, 가족과 함께하는 일(활동) 관련 프로그램은 중요도와 지식 정 도 모두 낮아 개선영역으로 나타났다, 결과적으로 노인의 의미 있는 활동을 위해서는 경쟁우위 영역에 해당하는 지역공동체를 활용한 사회참여 활동 의 활성화를 시키고, 개선영역에 해당하는 가족과 함께하는 일(활동) 관련 프 로그램에서 특히 아픈 가족 돌보는 방법 및 효과 등의 사회적 돌봄 프로그 램의 활성화를 위한 제도적 지원이 필요할 것이다.

본 연구에서는 경기도내 유통되고 있는 심해성 어류 50 건을 대상으로 수은, 메틸수은의 오염도 및 셀레늄의 함 량을 알아보았다. 금아말감법의 수은분석기, ICP-MS를 사 용하여 측정하였으며 각 항목별 평균함량은 수은 0.7647 mg/ kg (0.0182-5.3620), 메틸수은 0.0764 mg/kg (0.0096-0.8750), 셀레늄 0.4728 mg/kg(0.1075-3.5100)으로 메틸수은은 50건 모두 기준규격(1.0 mg/kg) 이하로 나타났다. 셀레늄은 수 은과 결합하여 수은의 독성을 감소시키는 것으로 알려져 있으며, 본 연구과제에서는 일일평균섭취량이 3.3 μg/kg으 로 일일권장량보다 낮은 수치였다. 유해물질인 수은과 메 틸수은은 JECFA에서 설정한 PTWI의 5.7%, 1.8%로 조사 되었다. 따라서 도내에서 유통되는 심해성 어류의 수은, 메틸수은과 같은 위해중금속은 안전한 것으로 나타났지만 지속적 모니터링이 필요하다고 판단된다.

This research was conducted to reduce the defect rate caused by nozzle clogging of printing heads used in binder jet 3D printers. The binder jet 3D printing technology may adhere to the printing head nozzle by dispersing powder due to mechanical operation such as transferring the printing head and supplying powder, and may cause nozzle clogging by natural curing at the nozzle end depending on the type of binder used. To solve this problem, this study created a cleaning module exclusively for printing heads to check whether the durability of printing heads is improved through analysis of printing results before and after using the cleaning module. To this end, this research used a thermal bubble jet printing head, and the used powder was studied using gypsum powder.

Cyanobacteria Pseudanabaena strains are known to produce 2-MIB (odorous material) in freshwater systems, thereby causing problems in water use. However, their physiological responses to environmental factors in relation with 2-MIB production is not well explored. This study was conducted to evaluate the effect of temperature on the growth and 2-MIB production of Pseudanabaena redekei. The experimental cyanobacteria strains were separated from the Uiam Reservoir (North Han River) and cultured in the BG-11 medium. Temperature was set to 10, 15, 20, 25, and 30℃ for the experiment, in the reflection of the seasonal water temperature variation in situ. For each temperature treatment, cyanobacterial biomass (Chl-a) and 2-MIB concentration (intra-cellular and extra-cellular fractions) were measured every 2 days for 18 days. Both maximal growth and total 2-MIB production of P. redekei appeared at 30℃. While intra-cellular 2-MIB contents were similar (26~29 ng L-1) regardless of treated temperatures, extra-cellular 2-MIB concentration was higher only in high temperature conditions (25~30℃), indicating that the extents of 2-MIB biosynthesis and release by P. redekei vary with temperature. The 2-MIB productivity of P. redekei was much higher in low-temperature conditions (10~15℃) than high temperature conditions (25~30℃). This study demonstrated that temperature was a critical factor contributing to 2-MIB biosynthesis and its release in cell growth (r=0.605, p<0.01). These results are important to understand the dynamics of 2-MIB in the field and thereby provide basic information for managing odorous material in drinking water resources.

본 연구에서는 울산지역에서 유통되는 로컬푸드 농산물 367건에 대해 다성분 분석법을 이용하여 잔류농약 350종 을 분석한 결과 다음과 같다. 로컬푸드 농산물에 대한 잔류농약 분석 결과 21.5%(79 건)의 검출률을 보였으며 부적합률은 1.1%(4건)으로 나타 났다. 품목별로 과일류는 65건 중 27건(41.5%), 채소류는 242건 중 50건(20.7%), 두류는 7건 중 1건(14.3%), 곡류 11건 중 1건(9.1%) 검출률을 보였고, 취나물, 곤달비, 파, 살구에서 기준치 이상의 잔류농약이 검출되었다. 검출된 잔류농약은 총 58종 163회로 살충제 성분이 가 장 많이 검출되었고 고독성 농약 1회, 보통 독성 농약 9 회, 저독성 농약이 48종이었다. 부적합 처리된 품목을 포함한 검출된 잔류농약 항목에 대한 위해도 평가 결과 위해지수(%ADI) 가 0.0000- 63.1043% 으로 모두 100% 미만으로 위해하지 않은 수준 으로 판단되었다. 지속적으로 로컬푸드 농산물의 운동 추진 방향인 지역 활성화와 안전한 먹거리 공급체계구축의 목적을 위해 엄 격히 관리되는 기준으로 안전성 검사를 실시하고, 신뢰성 확보를 위한 생산자 교육 및 홍보, 출하 전 안전성 검사 관리시스템이 정착된다면 울산지역 로컬푸드 농산물 사업 이 더욱 활성화되고 지속적으로 추진 될 수 있을 것으로 판단된다.