In this paper, we aim to improve the output quality of a food 3D printer through optimized component design and implementation. Existing 3D printers produce customized outputs according to consumer needs, but have problems with output speed and poor quality. In this paper, we aim to solve this problem through optimized design of unit parts such as the extruder, nozzle, guide, and external case. Fusion 360 was used for element design, and in the performance evaluation of the implemented system, the average precision was 0.06mm, which is higher than the non-repeatable precision of ±0.1㎜ of other products, and the feed speed of the existing system was evaluated to be more than twice as fast, from 70mm/s to 140mm/s. In the future, we plan to continuously research output elements that can produce texture and color and device control methods for convenience.

Molybdenum, valued for its high melting point and exceptional physical and chemical properties, is studied in diverse fields such as electronics, petrochemicals, and aviation. Among molybdenum oxides, molybdenum dioxide stands out for its higher electrical conductivity than other transition metal oxides due to its structural characteristics, exhibiting metallic properties. It is applied as pellets to gas sensors, semiconductors, and secondary batteries for its properties. Thus, research on molybdenum dioxide compaction and pressureless sintering is necessary, yet research on pressureless sintering is currently insufficient. This study synthesized MoO₃ powder via solution combustion synthesis and reduced it using the 3% hydrogen/argon gas mixture to investigate the effect of reduction temperature on the powder. Additionally, the reduced powder was compacted and subjected to pressureless sintering with temperature as a variable. The density and the microstructure of brown parts were analyzed and discussed.

본 논문은 최근 6년간(2018년~2023년) 한국의 주력 산업인 반도체, 디스플레이, 전 기·전자, 자동차 등 HS 6단위 기준 총 94개 품목을 대상으로 수출편향지수(EBI), 대 칭적 현시비교우위지수(RSCA), 불변시장점유율(CMS) 등 무역통계지표를 통해 한· 중 양국의 소재·부품·장비의 경쟁력과 수출증감요인을 분석하였다. 분석 결과, 반도 체 관련 품목의 대중국 수출편향이 증가한 반면 디스플레이 품목은 EBI 지수 감소 하고 있어 중국 내 품목으로 대체되고 있는 것으로 추정할 수 있었다. 또한 자동차 관련 품목의 EBI 지수가 전체 분석 기간 1 이하로 중국에 대한 수출집중도가 낮을 뿐 아니라 수입 편향에 있음을 확인할 수 있었다. 대칭적 현시비교우위지수(RSCA) 분석에서 품목별 차이는 있지만 전기·전자 품목은 세계시장에서 상대적으로 낮은 경 쟁력을 보유하고 있었다. 반면 반도체, 디스플레이 및 자동차 관련 품목은 일부 품목 을 제외하고 중국과 비교하여 비교우위를 나타내고 있었다. 불변시장점유율(CMS) 분석에서 기준년도(2018년) 대비 비교연도(2023년)의 한국의 대중국 감소 요인이 수 입규모요인보다 경쟁력요인과 수입구조요인이 더 큰 영향을 미치는 것으로 분석되었 다. 이는 한국의 소재·부품·장비 관련 품목의 경쟁력 감소와 일본 등 제3국의 경쟁력 상승으로 인해 한국의 대중국 수출 감소를 가져온 것으로 추정되었다.

Sha Zhi’s “Stein’s Third Central Asian Chinese Literature (Non-buddhist Parts)” (hereinafter referred to as “Stein”) interprets and publishes the Chinese documents obtained by Stein during the Third Western Regions (Central Asia) Expedition from 1913 to 1916 through photocopying of the original text and comparison of pictures and texts. Most of these interpretations are relatively accurate, and they are important results of the interpretation of documents unearthed in the Western Regions. Because most of these documents are handwritten documents and vulgar characters, it is still difficult to completely and accurately identify them. This article further examines the very few interpretations of Stein that are mistranscribed due to unclear terms, unidentified vulgar styles, and similar glyphs, in order to contribute to the study of documents excavated in the Western Regions.

본 연구는 자동차부품제조기업종사자들의 조직공정성이 직무만족에 미치는 영향에 대한 조직후원인식의 매개효과를 규명 하는데 있다. 선 행연구를 기반으로 한 설문지를 자동차부품제조기업종사자를 대상로 배 포하여 148부가 회수되었으며, SPSS 20.0 통계 분석 프로그램을 사용 하여 통계 분석을 실시하였다. 분석 결과, 조직공정성은 직무만족에 유 의미한 정(+)의 영향을 미쳤으며, 조직후원인식은 매개 효과가 있는 것 으로 나타났다. 이에 따라 첫째, 조직공정성이 강화될수록 직무만족에 미치는 영향이 있는 것을 알 수 있었다. 둘째, 조직후원인식이 조직공정 성과 직무만족간의 매개효과를 확인할 수 있었고 이는 조직구성원들의 노력과 성과에 가치를 두고 복지를 증대시키면 조직후원인식을 통해서 직무만족을 더 잘 할 수 있음을 의미한다. 이는 조직후원인식을 통하여 조직공정성을 강화함으로써 직무만족을 향상 할 수 있는 가능성을 시사 한 것으로 볼 수 있다.

Along This paper deals with research on firearm barrel processing and aims to improve firearm performance, accuracy, and machinability. The barrel is one of the key parts of a firearm and has a direct impact on shaping the trajectory of ammunition. In particular, durability and reliability are required due to the enormous heat generated as the bullet passes through. In this study, experiments were conducted under the processing conditions used in barrel processing to identify and analyze the characteristics. Various technologies and methods were investigated and analyzed. To achieve this, the cutting force generated during conventional barrel processing was measured to determine the level of stress on the material. In addition, we determined the suitability of tools and cutting conditions used in metal processing to identify conditions that can maximize productivity. This paper is expected to contribute to improving firearm performance by suggesting a plan to optimize processing conditions to the firearms manufacturing industry. Additionally, it can be used as a reference for barrel processing by other researchers.

This study was performed to investigate antioxidant and anti-inflammatory activities of perilla(Perilla frutescens L.) seed, flower and leaf according to extraction condition. Perilla seed extracts(PSE), perilla flower extracts(PFE), perilla leaf extracts(PLE) was extracted by stirring extraction (STE, 25°C), shaking extraction (SHE, 80°C), and sonication assisted extraction(SAE, , 25°C) with 94% ethanol, 60% ethanol and distilled water, followed by analysis of total polyphenol and flavonoid and testing radical scavenging activities. The highest total polyphenol content (5.47, 9.36, 38.58 mg gallic acid equivalent/g), total flavonoid content(5.77, 8.62, 46.44 mg catechin equivalent/g), ABTS(10.68, 19.46, 63.56 mg trolox equivalent/g) and DPPH(6.51, 7.69, 79.73 mg trolox equivalent/g) radical scavenging activity of PSE, PFE and PLE was observed in the HWE with 60% ethanol,. Among the three extraction method, SHE provided the best results for yield, polyphenol, flavonoid content of perilla seed, flower, leaf in comparison to STE or SAE. SHE with 60% ethanol of perilla seed, flower, leaf more effectively inhibited secretion of nitric oxide(NO) and pro-inflammatory cytokine in RAW 264.7 macrophage exposed to LPS compared to other extraction solvent and method. Therefore, these extracts obtained from perilla seed, flower, leaf could be used antioxidant and anti-inflammatory ingredients in the food industry.

In this study, the quality of sow pork was compared with commercial pork to evaluate sow pork as raw meat material for processing. Texture, cooking loss, color, pH, water, lipid, fatty acid, volatile profiles, and sensory characteristics of 3 parts (tenderloin, loin, hind leg) of sow and commercial pork were analyzed. In texture analysis, sow pork had significantly higher shear force compared to commercial pork (tenderloin: sow 143.19 N, commercial 107.79 N; loin: sow 173.62 N, commercial 120.65 N; hind leg: sow 211.76 N, commercial 112.80 N) (p<0.05). There were significant differences in cooking loss, color, and pH, but they differed by part. A total of 49 volatile compounds were identified, and there were significant differences in 22 volatile compounds. In the case of hexanal (one of the warmed-over flavors), which was detected on the largest scale, the relative concentration was significantly higher in the tenderloin of commercial pork (p<0.05). On the other hand, no differences were reported by sensory analysis for hardness, off-flavor, juiciness, oiliness, appearance, taste, and acceptability between cooked sow and commercial pork. This study provides a database on the quality of sow pork by parts, which is considerable to develop proceed meat products using sow meat.

Recently, as ESG management has become an important issue, major companies in the automotive parts manufacturing industry are conducting ESG evaluations of their suppliers for the purpose of supply chain management. The results of these evaluations are being incorporated into contractual agreements. However, many small and medium-sized enterprises(SMEs) are lacking in their capacity and resources to effectively respond to ESG evaluations. Furthermore, existing ESG management guidelines do not provide an industry-specific guidance, making it necessary to establish industry-specific guidelines that SMEs can refer to. Therefore, in this study, the evaluation Indicators of ESG supply chain assessments are surveyed, which is conducted by domestic major automotive parts companies and global automobile manufacturers. Then 56 supply chain ESG evaluation Indicators are derived. Also, ESG management indicators for SMEs is analyzed through the Importance-Performance Analysis(IPA), based on an interview of expert groups. Therefore, this study could propose industry-specific ESG guidelines, based on the results of the derived indicators, which reflects the need for SMEs to practice ESG management within certain boundaries.

Recently, there has been an increasing demand for independent suspension systems in commercial vehicles, and various researches related to this trend are currently underway. In this study, as part of an effort to localize the independent suspension system for commercial vehicles, a preceding study was conducted to convert the existing forging process into a casting process. The structural stability of the developed product was evaluated by performing stress analysis on both forging and casting materials. In order to compensate for the low yield characteristics of the casting material, design improvements were made to lower the maximum stress level based on numerical simulations.Additionally, Lightweight design was performed, capitalizing on the inherent design flexibility offered by casting products. As a result, it was confirmed that the developed product exhibited similar stress characteristics level to the existing product, along with a weight reduction of approximately 5%.

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.

In the pressurized water nuclear reactors (PWRs), the upper and bottom head penetration nozzles, the geometric asymmetry of the welded part increases from the center to the outer part, increasing the possibility of defects. For this reason, it is important to perform early detection and management through analysis of defects occurring in the welded parts of upper and bottom penetration nozzles of reactor vessel. However, it is very difficult to operate boat sampling of the welding area because the spacing of the penetration nozzle of the bottom head of the reactor is very narrow. In addition, it is more difficult to collect welded specimens of bottom penetration nozzles by electrical discharge machining in a boric acid water environment of nuclear reactor. In this work, to overcoming these technical difficulties, we developed a boat sampling robot system, which is composed of the specimen collection electrode head, borate-mediated discharge electrode and control system. Also, we performed basic performance tests and summarize the results.

Laparoscopy instrument requires blood vessel ligator to prevent blood leakage. Clip ligation device is widely used to prevent blood loss and secure surgical vision by using blood vessel ligator. However, in order to properly install the clip to the vessel ligator and ligate the blood vessel by the ligation machine, the device is properly operated and the parts constituting the jaw areas should be ensuring sufficient strength and rigidity during the operating. Therefore, the clip binding forces were calculated through a dynamic model of the blood vessel ligator. As a result, the force satisfies the target value of 8.5 N or more regardless of the grip force positions. And structural analysis was carried out to find out the maximum resistance force at the tip of the inner shaft. The maximum load was about 45.6 N, which sufficiently satisfies the development target of 40.0 N or higher.

In modern society, the delivery service market has grown explosively due to rapid changes in social structure and the recent COVID-19 pandemic. Therefore, various problems such as injury to workers and an increase in human accidents are occurring due to the loading and unloading of parcels. In order to solve this problem, domestic company n is developing a “robot-based cargo loading and unloading system”. In developing a new technology system, quantitative reliability targets should be set for efficient operation and development. In this paper, reliability analysis was conducted through field data for the pneumatic gripper of the “robot-based cargo loading system”. The reliability of the failure data was analyzed to estimate the distribution parameters and MTTF. Random data was derived for the probability of occurrence of a failure with the estimated value. By repeating the simulation to predict the number and year of failures according to the estimated parameters of the probability distribution, it was proposed as a method that reflects realistic probabilities rather than calculating with simple arithmetic using the average MTTF previously used in the field.

본 연구는 소재·부품·장비의 한·중 산업간 무역구조 및 무역 경쟁력의 변화를 분 석하기 위하여 수행되었다. 먼저 수출입 추세를 보았을 때 소재·부품·장비의 대중국 무역은 지난 10여 년간 지속적으로 무역수지 흑자를 달성하고 있지만 흑자 규모는 지속적으로 하락하는 추세에 있는 것으로 나타났다. 그리고 GL 지수를 보았을 때 산 업 내 무역의 수준이 지속적으로 증가하고 동종 산업 간의 경쟁 또한 치열해지고 있 는 것으로 파악되었다. 10년간 전체 소재·부품·장비 산업의 TSI 지수는 양(+)으로 나 타나 우리나라 산업의 경쟁력이 우세한 것으로 나타났지만 TSI 지수가 지속적으로 줄어들어 산업의 경쟁력이 점차 감소하고 있는 것으로 파악되었다. 중국의 급격한 성장에 대응하기 위해서는 우리 제품의 자급률 향상 및 경쟁력 강화 등을 위한 노력 을 지속적으로 기울여야 할 것으로 판단이 된다.

This paper addresses the maintenance optimization problem in multi-component systems in which parts are connected in series, carrying out several missions interspersed with scheduled finite breaks. Due to limited time or resources, maintenance actions can be only carried out on a limited set of components. The decision maker then has to decide which components to maintain to ensure a pre-specified performance level during next mission. Most of the existing models in the literature usually assume only one system and enough spare parts. However, there are situations in which maintenance is required for multiple systems of the same type. To overcome this restrictive assumption, this study optimizes the maintenance problem considering the lack of repair parts and cannibalism for many identical systems. This study presents two optimization models with different objectives to solve the problem and analyzes the results so that the decision maker can decide. The results of this study are expected to be used for the maintenance of multiple systems of the same type, such as swarm drones.