This study develops a model to determine the input rate of the chemical for coagulation and flocculation process (i.e. coagulant) at industrial water treatment plant, based on real-world data. To detect outliers among the collected data, a two-phase algorithm with standardization transformation and Density-Based Spatial Clustering of Applications with Noise (DBSCAN) is applied. In addition, both of the missing data and outliers are revised with linear interpolation. To determine the coagulant rate, various kinds of machine learning models are tested as well as linear regression. Among them, the random forest model with min-max scaled data provides the best performance, whose MSE, MAPE, R2 and CVRMSE are 1.136, 0.111, 0.912, and 18.704, respectively. This study demonstrates the practical applicability of machine learning based chemical input decision model, which can lead to a smart management and response systems for clean and safe water treatment plant.
국내에서 제조되어 유통되는 식물성 대체육을 대상으로 일반성분(수분, 단백질, 지방), 지방의 산패도, 지방산의 조 성, 아플라톡신, 중금속 함량을 분석하였다. 그 결과 한번 익힌 후 건조된 형태의 식물성 대체육보다 익히지 않고 수분이나 지방에 의해 성형과정을 거친 냉동제품에서 상 대적으로 많은 양의 지방을 함유하고 있음을 확인할 수 있었다. 조지방 함량이 1 g을 넘는 시료를 대상으로 지방 의 산패도(산가, 과산화물가)를 측정했다. 그 결과 일부 시 료에서 높은 산가 및 과산화물가가 측정되었으나 식품공 전상에 대체육에 대한 정확한 분류가 되어있지 않아 산패 도에 대한 안전성을 판단하기 위한 규격이 필요해 보인다. 가스크로마토그래피를 사용하여 지방산 조성을 분석한 결 과 대부분은 불포화지방산이 차지하고 있지만, 일부 포화 지방산의 함량이 높은 시료가 있었다. 포화지방산 및 불 포화지방산의 함량이 높은 식물성 대체육을 식물성 유지 를 사용하여 가열조리를 거쳐 섭취하게 된다면, 많은 양 의 지방을 섭취하게 될 수 있음을 예측할 수 있다. 또 가 스크로마토그래피를 사용한 지방산 분석법을 통해 식물성 대체육에 동물 유래 지질이 함유되어있지 않음을 확인할 수 있었다. 이는 이후에 식물성 대체육에 대한 영양표시 성분 및 실제성분의 대조 시에 활용될 수 있음을 시사한 다. 식물성 대체육에 대하여 아플라톡신을 분석한 결과 현 재 식품공전에 제시된 농산물 중 아플라톡신 기준규격에 대하여 적합인 수준이나 미량 검출되는 것을 확인하였다. 중금속의 분석 결과 모두 불검출이었으나 환경요인 및 원 재료에 따라 중금속의 오염이 의심될 시에 중금속 분석을 진행할 수 있을 것으로 판단된다. 이러한 실험결과를 통 해 국내에 유통되고 있는 일부 식물성 대체육에 대한 안 전성을 확인하였으나 산가, 과산화물가, 아플라톡신, 중금 속은 대체육에 대하여 구체적인 분류 및 적합 규격이 마 련되어 있지 않아 적합 판정시에 비슷한 성향을 가진 식 품군에 대조하여 판단해야 하는 어려움이 있었다. 따라서 기존의 기준에 대하여 검토 또는 변경을 거쳐 식물성대체 육에 대한 관리기준이 설정한다면 유사한 식품군의 건전 성 및 적합성을 유지하는 것에 도움이 될 것으로 판단된다.
High-strength low-alloy steel is one of the widely used materials in onshore and offshore plant engineering. We investigated the alloying effect of solute atoms in α-Fe based alloy using ab initio calculations. Empirical equations were used to establish the effect of alloying on the Vicker’s hardness, screw energy coefficient, and edge dislocation energy coefficient of the steel. Screw and edge energy coefficients were improved by the addition of V and Cr solute atoms. In addition, the addition of trace quantities of V, Cr, and Mn enhanced abrasion resistance. Solute atoms and contents with excellent mechanical properties were selected and their thermal conductivity and thermal expansion behavior were investigated. The addition of Cr atom is expected to form alloys with low thermal conductivity and thermal expansion coefficient. This study provides a better understanding of the state-of-the-art research in low-alloy steel and can be used to guide researchers to explore and develop α-Fe based alloys with improved properties, that can be fabricated in smart and cost-effective manners.
원자력발전소 지진 확률론적 안전성 평가인 PSA(Probabilistic Safety Assessment)는 오랜 기간에 걸쳐 확고히 구축되어 왔다. 반면 에 다양한 공정 기반의 산업시설물의 경우 화재, 폭발, 확산(유출) 재난에 대해 주로 연구되어 왔으며, 지진에 대해서는 상대적으로 연 구가 미미하였다. 하지만, 플랜트 설계 당시와 달리 해당 부지가 지진 영향권에 들어갈 경우 지진 PSA 수행은 필수적이다. 지진 PSA 를 수행하기 위해서는 확률론적 지진 재해도 해석(Probabilistic Seismic Hazard Analysis), 사건수목 해석(Event Tree Analysis), 고장수 목 해석(Fault Tree Analysis), 취약도 곡선 등을 필요로 한다. 원자력 발전소의 경우 노심 손상 방지라는 최우선 목표에 따라 많은 사고 시나리오 분석을 통해 사건수목이 구축되었지만, 산업시설물의 경우 공정의 다양성과 최우선 손상 방지 핵심설비의 부재로 인해 일 반적인 사건수목 구축이 어렵다. 따라서, 본 연구에서는 산업시설물 지진 PSA를 수행하기 위해 고장수목을 바탕으로 확률론적 시각 도구인 베이지안 네트워크(Bayesian Network, BN)로 변환하여 리스크를 평가하는 방법을 제안한다. 제안된 방법을 이용하여 임의로 생성된 가스플랜트 Plot Plan에 대해 최종 BN을 구축하고, 다양한 사건 경우에 대한 효용성있는 의사결정과정을 보임으로써 그 우수 성을 확인하였다.
Physicochemical properties and storage stability of plant-based alternative meat prepared with low-fat soybean powder (LPAM) treated by supercritical-CO2 and those of full-fat soybean powder (FPAM) were compared. Ash and crude protein contents were higher in LPAM than in FRAM. Water absorption capacity and oil absorption capacity were significantly higher in LPAM than in FPAM. Water binding capacity was higher in LPAM than in FPAM during a 20 days storage period at 5℃ and pH was significantly lower in LPAM than in FPAM after a 5~10 days storage period. Hardness, gumminess and chewiness significantly increased with the increase in the storage period, and the three were significantly higher in LPAM than in FPAM after 10 days and 20 days of storage. The acid value showed no remarkable difference according to the storage period in LPAM; however, it was significantly higher in FPAM than in LPAM after 20 days of storage. The peroxide value and TBA value were significantly increased according to the storage period, and were significantly lower iin LPAM than in FPAM during all the storage periods. Therefore, the use of low-fat soybean powder may be effective in improving oxidative stability during storage in the production of plant-based alternative meat.
This study investigated the awareness and consumption behavior of 118 vegetarians and omnivores toward plant-based dairy alternatives. The preference and choice attribute questionnaires were compared. Significant differences were obtained between the two groups when considering the purchase experience, preference, and selection attributes of plant-based dairy alternatives. Vegetarians had more experience purchasing plant-based dairy alternative products. In both groups, environmental and animal protection were the major factors that influenced the highest response rate for purchasing plantbased dairy alternatives. The preference score of vegetarians for plant-based dairy alternative products was high, indicating that vegetarianism had a significant effect on their preference for plant-based dairy alternative products. Analysis of selection attributes revealed that price, product weight, appearance, and manufacturer were considered important by vegetarians, whereas nutritional components and labeling, manufacturing environment, composition of ingredients, and taste and texture were considered more important by the omnivores. Results of this study can be used as basic data for the future development of the fast-growing industry producing plant-based dairy alternative products.
This study aims to investigate the physicochemical properties of meat analogs by using high and low moisture extrusion processes to create a plant-based analog burger patty material. The isolated soy protein blends of low- and high-meat analogs (LMMA and HMMA) were texturized using the twin-screw extruder equipped with a cooling die. The highest hardness, cohesiveness, chewiness, and cutting strength were observed in beef, but the highest stringiness was indicated in HMMA. The highest integrity index was seen in beef, while LMMA had the highest nitrogen solubility index (NSI). LMMA also had the highest water holding capacity (WHC) and water absorption capacity (WAC), whereas beef had the highest oil absorption capacity (OAC). LMMA had the highest emulsifying activity (EA) and emulsion stability (ES) in emulsifying properties. Further, the highest protein digestibility was revealed in LMMA. This study suggested that extrusion process types influence the quality of meat analog, which could be the elementary source for manufacturing the analog burger patty.
This study aims to investigate protein consumption market trends in Korea. Protein consumption was divided according to the protein source into meat, fishery, and plant-based protein. To accomplish the goal of this study, food purchase data from 525 households panels collected by the Rural Development Administration over the last 10 years were used. The results of the study showed an increase or decrease in protein consumption by protein type over the last 10 years, and a reason to explain this change has been suggested. Specifically, this study found a dramatic increase in the consumption of several proteins, including beef sirloin, beef tenderloin, seasoned beef & steak, pork belly, pork shoulder, pork neck, seasoned pork, pork cutlet, sweet and sour pork, canned ham, chicken drumstick, chicken breast, dak gangjeong, Chinese fried chili chicken, salmon, eel, abalone, squid, octopus, webfoot octopus, octopus minor, canned whelk, tofu, cold bean soup,and plant-based milk. Some items showed no increase in consumption (such as beef jerky, pork rib, sausage, bacon, whole raw chicken, cutlass fish, oyster, fish cake, crab stick, surimi sausage,and canned fishery), whereas a few items showed decreased consumption (e.g., mackerel, pollack, cod,and canned tuna)
Considering the characteristics of nuclear power plants in order to decommission nuclear power plants safely and economically, this thesis provides a methodology for optimizing the technology for developing decommissioning characteristic evaluation system using simulation technology for core facilities of the plants based on 3D that reflects various factors. The results of pollution assessment and radiation assessment for the Kori Unit 1 reactor building, auxiliary building, and each major device are displayed in 3D drawings and viewer, and the radiation dose rate and radiation assessment results are displayed separately for each major location. Furthermore, this D/B development method which includes inserting result values of characteristic evaluation and the quantity of waste is one of the main technology to optimize the system which enables users to select decommissioning processes and predict the quantity of waste. (Refer to the presented 3D models of the containment building, D/B, tag search module, the scale calculation result of models after visualizing the result value of 3D based decommissioning characteristic evaluation) The methodology for optimizing decommissioning characteristic evaluation result value DB development system using 3D models of the first major nuclear power plant allows the display of decommissioning characteristic values in virtual reality, the selection of decommissioning process, the establishment of the decommissioning procedure. Hence, this study is expected to provide reliable guidelines for managing a decommission business efficiently in the near future and can be used in the related field if needed.
This study identifies the perceptions and choice attributes toward plant-based foods and identifies the differences between vegetarians and omnivores. We conducted an online survey of 245 vegetarians and 246 omnivores. The results reveal a significant difference between vegetarians and omnivores. Compared to omnivores, vegetarians perceived that plant-based food products would be ‘good taste’, ‘animal-friendly’, and ‘consistent with their personal value’. Omnivore scores were higher in the perception that it would be ‘good for health’ and ‘environment-friendly’. No statistically significant difference was obtained between both diet groups when considering the factor of nutrition. When considering choice as an attribute for plant-based food products, vegetarians responded that ‘ingredients’ were the most important, while omnivores responded that ‘taste’ was the most important. These results can be used as basic data for developing and promoting plantbased food products in South Korea.
본 연구에서는 다양한 식물성 지방 대체제가 돼지고기 패티의 이화학적 특성 및 관능 특성에 미치는 영향을 평가 하고자 하였다. 동물성 지방 처리군, 식물성 기름 처리군, 비드 처리군 첨가에 따른 영향을 분석하였으며, 실험을 통해 지방 함량은 낮추면서 물리적 및 관능적 측면에서 돼지 등지방을 사용한 패티와 큰 차이를 나타내지 않음을 확인 하고자 하였다. 본 연구에서는 기존의 지방대체 방법인 식물성 기름 첨가와 식물성 기름 유화물 첨가 뿐 아니라 식물성 고체 지방 대체제를 제조할 수 있는 방법을 제시하였으며, 이를 육가공 제품에 적용하여 다양한 지방 대체제의 효과와 비교했다는 점에서 기존 지방대체 연구와 차이점이 있을 것으로 판단된다. 또한, 연구 결과 식물성 고체 지방 대체제는 패티의 조리손실을 줄이고 보수력을 개선하는 등 품질을 향상시킬 수 있었으며, 패티의 부드러움과 다즙성에 영향을 주어 선호도가 높은 것으로 분석되었다. 이는 새로운 지방 대체제의 적용 가능성에 대한 기초 연구 자료로 제공될 수 있다.