As coffee consumption increases, coffee extraction's by-products increase. Research on coffee by-product recycling is fundamental as social costs and environmental problems arise from the course of coffee processing, estimated to be 270,000 tons per year. This study attempted to confirm the possibility of an eco-friendly food packaging material by solvating cellulose from spent coffee grounds. For cellulose solubility, delignification and TEMPO (2,2,6,6- tetramethylpiperidin-1-oxyl) oxidation treatment were performed. An optimal plasticizer (glycerol) and a crosslinking agent (cinnamaldehyde) were added to the film-forming solution for film manufacturing, while physical treatment (high-pressure treatment, 276 MPa, 10 times) was done to improve physical properties. Then, the film was dried by a solution-casting method. Physical properties of food packaging materials such as tensile strength, elongation, water-solubility, thickness, and chromaticity were measured. In particular, the film to which 1.5% glycerol was added showed the highest value among the physical properties of the dried film. These results indicate that TEMPOSCG films have potential as eco-friendly food packaging materials in the food industry.

In general, if a nuclear fuel cladding tube is damaged during reactor operation, it is called fuel failure. If the cladding tube is damaged, the function of sealing the nuclear fuel material is lost, and the fission products accumulated inside the nuclear fuel rod may leak into the coolant. The causes are the most damage caused by foreign substances in a coolant such as small iron wires, and GTRF (Gridto- Rod Wear) due to a grid, end-plug welding defect, PCMI (pellet cladding mechanical interaction), and oxidation corrosion damage. In this study, a device of simulating friction damage and debris induced damage between grid-fuel rods, which are the main causes of cladding tube damage, was developed. An air vibrator was installed as a function to induce vibration of the nuclear fuel rod. Sandpaper was installed between the grid and the fuel rod to induce friction between the grid-fuel rods. Saw teeth were installed on the grid to induce damage to foreign substances. It is believed that the simulated damaged nuclear fuel rod can be manufactured through on-study to provide the simulated damaged nuclear fuel rod necessary for the stabilization study of the damaged nuclear fuel rod.

A porous photocatalyst concrete filter was successfully produced to remove NOx, by mixing TiO2 photocatalyst with lightweight aerated concrete. Ultra Fine Bubbles were used to form continuous pores inside the porous photocatalytic concrete filter, which was mixed via a bubble generation experiment. The optimal mixing condition was determined to be with 4% of the bubble generation agent B. NO removal specimens were prepared for various photocatalytic loading conditions, and the specimen containing 3% P-25 removed NO at a concentration of 1.03 μmol in 1 h. The NO removal rate of the porous photocatalytic concrete filter prepared in this study was 10.99%. This photocatalytic filter performance was more than 9 times the amount of NO removed by a general photocatalytic filter. The porous photocatalyst concrete filter for removing NOx developed in this study can be applied to various construction sites and the air quality can be solved by reducing NOx contributing to the formation of fine particles.

The purpose of this study is to improve the mechanical properties and develop manufacturing technology through self-soluble alloy powder flame spray coating on the surface of a run-out table roller for hot rolling. The roller surface of the run-out table should maintain high hardness at high temperatures and possess high wear, corrosion, and heat resistances. In addition, sufficient bonding strength between the thermal spray coating layer and base material, which would prevent the peel-off of the coating layer, is also an important factor. In this study, the most suitable powder and process for roll manufacturing technology are determined through the initial selection of commercial alloy powder for roll manufacturing, hardness, component analysis, and bond strength analysis of the powder and thermal spray coating layer according to the powder.

원형점토대토기에서 삼각형점토대토기로의 변천과정에 있어 가장 중요한 변화는 단연 구연부의 형 태와 제작기법이다. 지금까지 단면형태를 중심으로 다양한 연구가 이루어져 왔지만, 점토대토기 변천 의 요인에 주목한 연구는 많지 않다. 본고에서는 점토대토기의 구연부에 내포된 제작규범과 상징적 의미에 주목하여 구연부의 변천이 일어나게 된 요인을 추론하고자 하였다. 연구 대상은 사천 방지리유적에서 출토된 점토대토기로, 구연부의 제작기법을 분석하여 점토대토 기 제작패턴의 개념을 설정하고 단면형태와 내면형태, 지두흔과 정면흔의 조합을 통해 제작패턴을 분류하였다. 제작패턴은 점토대토기 구연부가 어떠한 의도에서 어떠한 방식으로 제작되었는지를 보 여주는 것으로, 점토대토기 구연부의 성격을 파악하고 점토대토기의 변화를 이해하는 토대가 된다. 이를 통해 도출된 제작의도에 범형의 개념을 적용하여 분석한 결과, 원형점토대토기와 삼각형점토대 토기의 제작은 유기적이며, 점토대토기의 변화는 구연부 제작방식의 변화로 인해 발생하는 것임을 알 수 있었다. 점토대토기의 구연부는 제작자, 나아가 집단의 정체성이 표현되는 부분으로, 일종의 상징적인 의미 가 부여되어 있다. 원형점토대토기는 점토대의 형태를 원형으로 유지하려는 제작규범 하에서 제작되 었으며, 삼각형점토대토기로의 변화 요인은 이러한 제작규범의 약화로, 제작규범의 약화는 점토대토 기 구연부에 대한 제작집단의 관념과 구연부 제작의 편의성에 대한 인식이 맞물려 일어난 것이다. 결 국 원형에서 삼각형으로의 변화는 외래계 요소의 영향이나 이주민에 의한 결과가 아니라 동일 집단 내에서의 변화라 볼 수 있다.

In this study, in order to confirm the relationship between technical innovation competence and corporate performance, the effect of technical innovation competence of small and medium-sized manufacturing companies on corporate performance was identified, and entrepreneurship, which plays a role as a driving force in triggering technical innovation competence, was analyzed to determine whether there is a mediating effect between them. To conduct the research, first, the research model was established by examining previous studies on technical innovation competence, entrepreneurship, and corporate performance. Second, an on-line and offline survey was conducted for employees in companies after constructing a questionnaire that can verify the hypothesis suitable for the research model. Third, the hypothesis was verified by performing validity and reliability analysis, correlation analysis, and regression analysis using a statistical program. Results of this study, first, it was found that R&D competence and technology innovation system, which are elements of technical innovation competence, had a significant effect on financial performance, and technology innovation system and technology accumulation capacity, had a significant effect on non-financial performance. Second, it was analyzed that entrepreneurship has a mediating effect in both R&D capability, technological innovation system and technology accumulation capability, which are elements of technical innovation capability, and financial and non-financial performance, elements of corporate performance.

Through the process of chemical vapor deposition, Tungsten Hexafluoride (WF6) is widely used by the semiconductor industry to form tungsten films. Tungsten Hexafluoride (WF6) is produced through manufacturing processes such as pulverization, wet smelting, calcination and reduction of tungsten ores. The manufacturing process of Tungsten Hexafluoride (WF6) is required thorough quality control to improve productivity. In this paper, a real-time detection system for oxidation defects that occur in the manufacturing process of Tungsten Hexafluoride (WF6) is proposed. The proposed system is implemented by applying YOLOv5 based on Convolutional Neural Network (CNN); it is expected to enable more stable management than existing management, which relies on skilled workers. The implementation method of the proposed system and the results of performance comparison are presented to prove the feasibility of the method for improving the efficiency of the WF6 manufacturing process in this paper. The proposed system applying YOLOv5s, which is the most suitable material in the actual production environment, demonstrates high accuracy (mAP@0.5 99.4 %) and real-time detection speed (FPS 46).

This article suggests the machine learning model, i.e., classifier, for predicting the production quality of free-machining 303-series stainless steel(STS303) small rolling wire rods according to the operating condition of the manufacturing process. For the development of the classifier, manufacturing data for 37 operating variables were collected from the manufacturing execution system(MES) of Company S, and the 12 types of derived variables were generated based on literature review and interviews with field experts. This research was performed with data preprocessing, exploratory data analysis, feature selection, machine learning modeling, and the evaluation of alternative models. In the preprocessing stage, missing values and outliers are removed, and oversampling using SMOTE(Synthetic oversampling technique) to resolve data imbalance. Features are selected by variable importance of LASSO(Least absolute shrinkage and selection operator) regression, extreme gradient boosting(XGBoost), and random forest models. Finally, logistic regression, support vector machine(SVM), random forest, and XGBoost are developed as a classifier to predict the adequate or defective products with new operating conditions. The optimal hyper-parameters for each model are investigated by the grid search and random search methods based on k-fold cross-validation. As a result of the experiment, XGBoost showed relatively high predictive performance compared to other models with an accuracy of 0.9929, specificity of 0.9372, F1-score of 0.9963, and logarithmic loss of 0.0209. The classifier developed in this study is expected to improve productivity by enabling effective management of the manufacturing process for the STS303 small rolling wire rods.

In this study, Korean Hallabong produced in Jeju Island and coffee were grafted to prepare coffee containing Hallabong extract and the nutritional components were analyzed. As the amount of Hallabong extract increased, the water content and total polyphenol content increased. However, the crude flour, crude protein, and total flavonoid content decreased significantly. The selenium content per 100 g was 91.28 mg in the 1% Hallabong group, and the iron content was 6.84 mg in the 3% Hallabong group. As the content of Hallabong extract in coffee increased, the L-value (brightness) and b-value (yellowness) increased, but the a-value (redness) showed a tendency to decrease. In the case of DPPH(2,2-Diphenyl-1-picrylhydrazyl) radical scavenging activity, the group containing 9% of Hallabong extract showed the highest value at 47.20 μmol/g of TEAC. In particular, the ABTS(2,2’-Azino-bis(3-ethylbenzothiazoline- 6-sulfonate)) and DPPH radical scavenging activity were significantly increased from coffee powder containing 6% or more of Hallabong extract(p<0.05). The caffeine content decreased as the amount of Hallabong extract added to coffee increased. Therefore, when making powder coffee with Hallabong extract added, it is recommended to set the content of Hallabong extract to 6%.

본 연구에서는 한국 전통 과자인 유과와 강정을 원·부재료와 기기 및 도구, 작업자의 개인위생, 제조공정별 원료에 대한 미생물학적 오염을 분석하였다. 유과제조 과정 중 현장에서 사용하고 있는 세척 방법과 횟수에 따른 미생물 저감효과를 확인하고자 하였다. 강정의 제조 공정 중 튀밥에서 일반세균수 1.2 Log CFU/g, 완제품의 경우 3.7 Log CFU/g까지 점차 증가하였다. 유과의 제조 공정 중 일반세균수는 불림공정에서 일반세균 최대 6.5 Log CFU/g 수준으로 증가하다가 튀김공정에서 1.3 Log CFU/g수준으로 감소하였으나 완제품에서 4.0 Log CFU/g 수준으로 재오염되는 것으로 확인되었다. 이는 제조과정 중에 작업도구와 기기 또는 작업자 등에 의한 교차오염으로 판단되었다. 작업 도구인 주걱의 경우 일반세균 약 4.4 Log CFU/g, 대장균군 4.2 Log CFU/g으로 매우 오염도가 나타났다. 유과의 불림단계에서 7일동안 일반세균 수가 최대 10 Log CFU/g 이상, 대장균군의 경우 6.8 Log CFU/g으로 증가하였다. 손 또는 도구를 이용한 세척 방법과 흐르는 물에 세 척한 방법을 비교하였을 때, 손을 이용하여 수돗물로 10 회 세척하였을 때 일반세균 5.0 Log CFU/g, 대장균군 2.8 Log CFU/g 감소한 것으로 확인되었다. 이상의 결과로 볼 때, 소규모 업체의 전통 한과 제조 시 작업자나 작업 도 구 및 기기 사용 후 세척 및 소독하는 과정이 요구되며 완제품의 미생물 오염도를 감소시키기 위해 현장에 적용할 수 있는 저감화 방법이 필요한 것으로 판단되었다.

The process optimization of directed energy deposition (DED) has become imperative in the manufacture of reliable products. However, an energy-density-based approach without a sufficient powder feed rate hinders the attainment of an appropriate processing window for DED-processed materials. Optimizing the processing of DEDprocessed Ti-6Al- 4V alloys using energy per unit area (Eeff) and powder deposition density (PDDeff) as parameters helps overcome this problem in the present work. The experimental results show a lack of fusion, complete melting, and overmelting regions, which can be differentiated using energy per unit mass as a measure. Moreover, the optimized processing window (Eeff = 44~47 J/mm2 and PDDeff = 0.002~0.0025 g/mm2) is located within the complete melting region. This result shows that the Eeff and PDDeff-based processing optimization methodology is effective for estimating the properties of DED-processed materials.