In this study, We designated the injection molded plug housing for charging electric vehicles as a research subject. And we analyzed the effect of Rib design on the quality of injection molded products. First, we used the Taguchi method to derive optimal conditions for rib design. The factors were set as the Thickness of the rib, the Height of the rib, and the Radius of the rib. Each factor consisted of 5 levels and generated conditions for a total of 125. We performed an injection molding analysis and confirmed significant factors affecting the deformation of injection molded products through ANOVA. Based on this, the 25th design detail was selected as the optimal condition. In addition, We compared the results of the molding analysis with the molded products that did not design ribs. We confirmed that the molded product designed with ribs under optimal design detail improved the deformation amount by 22.22% and the residual stress by 8.35%, compared to the molded product not designed with ribs.

In this paper, we design a basic algorithm enabling recognition of surrounding environment and collision avoidance among elemental technologies for autonomous driving, also applies sensor theoretical data and actual road performance to robo-racing system based on experimental data obtained through driving tests to enable sophisticated collision avoidance. For this study, a commercial autonomous driving patform(ERP-42), LiDAR and GPS sensors were used to implement efficient comunication systems and autonomous driving algorithms between each module.

중금속은 생체 내에서 분해되지 않고 장기간에 걸쳐 축적되는 특성으로 도시의 생물 다양성을 위협하는 위험한 오염물질 중 하나이다. 도시지역의 대기 중 중금속오염을 평가하기 위해 중금속 노출 정도에 따라 생물 체내의 축적농도 를 비교하는 생물학적 모니터링의 필요성이 요구되고 있다. 본 연구는 중금속 모니터링 시료로서 둥지 재료의 활용 가능성을 검토하고 중금속이 박새과 조류에 미치는 영향을 파악하기 위해 수행되었다. 연구지역은 충청남도 천안시 소재 대학교 캠퍼스 내 녹지공간(14개), 도시산림(11개), 도시공원(29개)으로 총 54개의 인공새집이 설치되었다. 조류 이용률은 도시공원 6/29개(20.68%), 캠퍼스 내 녹지공간 11/14개(78.57%), 도시산림 8/11개(72.72%)로 나타났다. 수거한 둥지로부터 이끼 재료를 채취하였고 중금속 분석을 통하여 도시녹지 유형별 중금속축적특성과 중금속이 박새과 조류의 이소 성공 여부에 미치는 영향을 비교하였다. 분석결과 아연의 평균 농도는 228.08±209.62㎍/dry g, 납의 평균 농도는 17.67±6.72㎍/dry g로 나타났다. 도시녹지 유형별 아연농도는 유의한 차이를 나타내지 않았으나(Kruskal- Wallis test, p-value=0.28) 납 농도는 유의한 차이를 보였다(Kruskal-Wallis test, p<0.05*). 중금속 분석을 진행한 21개 의 박새과 조류 둥지 중 11개(52.38%)의 둥지에서 조류의 이소가 관찰되었다. 각 도시녹지 유형에서 관찰된 조류의 이소는 캠퍼스 내 녹지공간 7개(77.78%), 도시산림 6개(85.71%), 도시공원 1개(20%)로 주로 도시산림과 캠퍼스 내 녹지공간에서 이소가 확인되었다. 박새과 조류의 이소 성공 여부에 중금속 축적특성이 미치는 영향을 확인하기 위해 중금속 농도를 비교하였으나 통계적으로 유의한 차이는 나타나지 않았다(Zn : W=44, p-value=0.74, Pb : t=0.64676, df =7.2422, p-value =0.54). 본 연구는 박새과 둥지 재료를 중금속 모니터링 시료로 사용한 기초 연구로 비침습적인 생물학적 모니터링의 기초자료로 활용될 수 있을 것으로 판단된다.

총리아문 장경 출신인 志剛은 1868년 벌링게임 사절단의 중국 대표 자격으로 미국 과 유럽을 견문한 내용을 일기 형식으로 기록하여 初使泰西記를 남겼다. 지강은 해외 경험을 통해 중국이 더 이상 세계의 중심이 아니며, 세계 속의 일국에 불과할 뿐이라는 점을 점차 인식하게 되었다. 중국이 새로운 국제 질서에 편입되어가는 어 쩔 수 없는 상황 앞에서 서양과의 외교 문제가 가장 중요하며, 조약이 갖는 중요성 또한 자각하게 되었다. 지강이 특별히 주목하였던 외교적 이슈는 해외 이주 중국인 들의 법적 권리 보호, 양주교안 처리를 둘러싼 영국과의 갈등, 철도·광산·鹽稅 등의 경제적 이권에 대한 것이었다.

A reliable prediction model of national occupational accident fatality rate can be used to evaluate level of safety and health protection for workers in a country. Moreover, the socio-economic aspects of occupational accidents can be identified through interpretation of a well-organized prediction model. In this paper, we propose a machine learning based relative comparison methods to predict and interpret a national occupational accident fatality rate based on socio-economic indicators. First, we collected 29 years of the relevant data from 11 developed countries. Second, we applied 4 types of machine learning regression models and evaluate their performance. Third, we interpret the contribution of each input variable using Shapley Additive Explanations(SHAP). As a result, Gradient Boosting Regressor showed the best predictive performance. We found that different patterns exist across countries in accordance with different socio-economic variables and occupational accident fatality rate.

국내 유통 중인 콜라겐 제품 120건을 대상으로 중금속 4종(납, 카드뮴, 비소, 수은) 함량에 대해 조사하였다. 수 은은 금아말감화법을 이용한 수은분석기로 분석하였고 납, 카드뮴, 비소는 ICP-OES를 이용하여 분석하였다. 검사 결 과 납의 평균 함량은 0.097±0.055 mg/kg이었고 건강기능 식품, 기타가공품, 음료류, 과·채가공품에서 각각 평균 0.108±0.052mg/kg, 0.084±0.053 mg/kg, 0.131±0.047 mg/ kg, 0.149 mg/kg 농도로 검출되었다. 카드뮴의 평균 함량 은 0.026±0.011 mg/kg이었으며 검출된 제품은 모두 건강 기능식품이었다. 비소의 평균 함량은 0.097±0.048 mg/kg 이었고 건강기능식품, 기타가공품, 과·채가공품에서 각각 평균 0.091±0.055 mg/kg, 0.133 mg/kg, 0.086 mg/kg 농도 로 검출되었다. 수은의 평균 함량은 0.0025±0.0016 mg/kg 으로 건강기능식품, 기타가공품, 과·채가공품, 캔디류에서 각각 평균 0.0012 mg/kg, 0.0028±0.0018 mg/kg, 0.0013 mg/kg, 0.0031 mg/kg 농도로 검출되었다. 중금속 기준·규 격이 있는 음료류(납 0.3 mg/kg, 카드뮴 0.1 mg/kg) 및 캔 디류(납 0.2 mg/kg)는 모두 기준 이하로 검출되어 적합하 였다. 기준·규격이 없는 제품도 국내외 식품의 중금속 기 준과 보고된 식품 중금속 함량과 비교하였을 때 비교적 안전한 수준이라고 판단되었다.

This study analyzed Tuber melanosporum, Tuber aestivum,and Tuber magnatum, specifically the content of β-glucan, amino acids, nucleic acid-related substances, vitamin C, and ergosterol. The β-glucan content was highest in T. magnatum (20.54%). The free amino acid content was highest in T. aestivum, with the major amino acids being cystine, glutamic acid, and aspartic acid. The total amino acid content was the highest in T. magnatum, the primary amino acids being cystine, glutamic acid, and lysine. The content of nucleotide related compounds was the highest in T. magnatum (5.09 mg/100 g). The highest content of vitamin C (10.15 mg/100 g) and ergosterol (596.91 mg/100 g) was found in T. magnatum, which had the highest useful component content among the three truffles. Additional studies investigating the variation in useful components according to collection time and growth environment are needed.

PURPOSES : Owing to industrial development, the occurrence of continuous environmental damage such as abnormal weather is accelerating because of a rapid increase in carbon emissions. Therefore, various efforts are expended worldwide to realize a low-carbon ecofriendly society. In the construction industry, various efforts have been realized to reduce environmental pollution such as greenhouse gas emissions, for example by introducing eco-friendly materials and reducing industrial waste. In this study, an asphalt pavement technology that can reduce production and construction temperatures by more than 60 °C is developed to reduce the amount of carbon generated in the asphalt industry. METHODS : The performance of a half-warm asphalt binder developed using thermoplastic elastomers and low-temperature additives was assessed. In addition, the change in the quality of a mixture due to the use of the half-warm asphalt binder was evaluated. RESULTS : As the amount of thermoplastic elastomer used increases, the performance grade of the asphalt binder increases as well. When 3% or more of the elastomer is incorporated, the target performance grade of the asphalt binder is satisfied. In addition, by incorporating the thermoplastic elastomer and a low-temperature additive, the overall moisture and rutting resistance increased even at relatively low production and compaction temperatures. CONCLUSIONS : Additional measures to stabilize quality and improve economic feasibility will present a new paradigm for investigations into eco-friendly asphalt concrete pavements.

Synthetic Aperture Radar (SAR) images are affected by noise called speckle, which is very severe and may hinder image exploitation. Despeckling is an important task that aims to remove such noise so as to improve the accuracy of all downstream image processing tasks. Many different schemes have been proposed for the restoration of SAR images. Among the different possible approaches, methods based on convolutional neural networks(CNNs) have recently shown to reach state-of-the-art performance for SAR image restoration. DnCNN(DeNoising Convolutional Neural Network) is one of the most widely used neural network architecture embedded in baseline SAR image despeckling methods. In military applications of SAR satellite image, fast processing is the most critical factor except the precision rate of the recognition. In this paper, we propose an improved DnCNN architecture for faster SAR image despeckling. The experimental results on real-world SAR images show that our proposed method takes faster processing time than the original DnCNN architecture without despeckling performance downgrade. Subjective visual inspection demonstrates that the proposed method has great potential in preserving the image signal details and suppressing speckle noise.

Anomaly detection for each industrial machine is recognized as one of the essential techniques for machine condition monitoring and preventive maintenance. Anomaly detection of industrial machinery relies on various diagonal data from equipped sensors, such as temperature, pressure, electric current, vibration, and sound, to name a few. Among these data, sound data are easy to collect in the factory due to the relatively low installation cost of microphones to existing facilities. We develop a real time anomalous sound detection (ASD) system with the use of Autoencoder (AE) models in the industrial environments. The proposed processing pipeline makes use of the audio features extracted from the streaming audio signal captured by a single-channel microphone. The pipeline trains AE model by the collected normal sound. In real factory applications, the reconstruction error generated by the trained AE model with new input sound streaming is calculated to measure the degree of abnormality of the sound event. The sound is identified as anomalous if the reconstruction error exceeds the preset threshold. In our experiment on the CNC milling machining, the proposed system shows 0.9877 area under curve (AUC) score.

The Moving Particle Semi-implicit (MPS) method is one of most famous method in the particle-based computational fluid dynamics field. The MPS, the state-of-art method, is simple but intuitive methodology including multi-phase and complex structure interactions problems. However, the concept of particle method may contain the physical weakness. In order to avoid physical violence, the particle number density and kernel function were employed. Despite all the efforts, the microscopic problems were not easily resolved yet. In this study, the surface tension model was developed and added into the MPS method to strengthen physical phenomena and physics laws. The simulation result with new MPS method including surface tension model was compared with corresponding theoretical results and they show good-agreement.

본 연구의 목적은 조업기인 어업쓰레기 발생(추정)량에 대한 어업 및 해양환경 정책의 범주별 차이를 비교하고, 독립변수와 종 속변수의 상관성을 분석하는 것이다. 독립변수는 세 가지로 구분되는데, 사전 예방정책, 현행 관리정책, 사후 대응정책이다. 사전 예방정 책에는 친환경어업 지원사업, 제도적 예방활동, 물리적 차단 시설 설치가 있다. 현행 관리정책에는 관련 선박 운영, 어업질서 확립, 어업 구조조정, 어장환경 개선이 해당된다. 사후 대응정책에는 하천~해안변 쓰레기 정화, 해양·침적·부유쓰레기 수거, 조업 중 인양쓰레기 수 매, 어업관련 폐기물 처리, 해양쓰레기 피해복구가 포함된다. 측정지표는 각 사업별 결산액이다. 종속변수는 조업으로 인한 어업쓰레기 발생 추정량이고, 측정지표는 연안 통발 및 자망과 그 부속어구 유실량의 합이다. 평균순위 차이 검증결과 어업쓰레기 발생 추정량은 해 역별로는 동해안이 가장 높게 나타났고, 기초자치단체별로는 시 지역이 가장 높게 나타났다. 해양환경 관련 결산액은 군 지역에서 가장 많이 투입하고 있었고, 대부분의 변수에서 유의한 차이가 나타났다. 어업쓰레기 발생 추정량과 관련있는 변수는 사후 정책 중 조업 중 인 양쓰레기 수매 사업과 폐기물 처리 지원 사업이었다.

The mineral content of Tricholoma matsutake was evaluated for comparison of mineral contents according to the area of cultivation. Ten domestic and thirty Chinese (10 Yanji, 10 Yunnan and 10 Tibet) T. matsutake specimens were assessed using an atomic absorption spectrophotometer (AAS) and inductively coupled plasma mass spectrometer (ICP-MS). The Na, Mg, K, and Ca contents of domestic T. matsutake were 128.12±85.25 mg/kg, 218.52±105.35 mg/kg, 7,534.58±2,691.52 mg/kg, and 17.69±7.14 mg/kg, respectively, while those of Yanji T. matsutake were 124.89±57.24 mg/kg, 64.07±27.52 mg/kg, 1,439.18±311.04 mg/kg, and 10.88±4.52 mg/kg, respectively. The Na, Mg, K, and Ca contents of Yunnan T. matsutake were 90.78±23.23 mg/kg, 77.40±28.36 mg/kg, 1,446.29 ±126.33 mg/kg, and 28.42±5.18 mg/kg respectively, while those of Tibet T. matsutake were 143.50±41.54 mg/kg, 124.64±50.18 mg/kg, 3,530.95±2,714.99 mg/kg, and 21.05±8.71 mg/kg, respectively. The Cu contents of domestic, Yanji, Yunnan, and Tibet T. matsutake were 105.43±32.97 mg/kg, 19.92±8.95 mg/kg, 54.51±16.91 mg/kg, and 64.80±23.01 mg/kg, respectively. Both domestic and Chinese T. matsutake samples showed significantly different K, Mg, and Cu levels in this study. Therefore, a comparative evaluation of the K, Mg, and Cu contents of multiple domestic and Chinese T. matsutake varieties is needed to determine the appropriate area of cultivation in the future.

In order to overcome the small scale of Korea waterworks and to achieve comprehensive improvement and innovation transformation, the waterworks integration was reviewed. The effect of consolidation was confirmed by the integration of the water supply business in the southern Gangwon region and the western Gyeongnam region in Korea, such as an increase in the flow rate and a decrease in the production unit cost. After facing management and service limitations overseas, more than 1,000 small-scale waterworks projects in the UK were integrated into 27 waterworks providers, and Japan also revised the Waterworks Act in December 2019 and is in the process of integrating waterworks. It is considered appropriate to promote the integration of waterworks projects in Korea by respecting the autonomy of local governments, but using a participatory method, a win-win method, and a linkage method. For the integration of waterworks projects, three strategies are proposed: First creating a national foundation for integration (revision of the Waterworks Act), Second establishing a waterworks integration strategy led by local governments, Third forming an external consensus and providing incentives for participation.

송국리형 주거지의 이용 및 폐기과정은 청동기시대의 흥미로운 연구 과제 중 하나이며, 특히 내부 흑색토층의 존재는 많은 관심을 끌어왔다. 송국리 유적 제24차와 25차 발굴조사에서 내부 흑색토층 이 확인된 주거지(98호, 100호, 107호)를 대상으로 환경고고학적 연구(토양 미세형태분석 및 규소체 분석)를 수행하였다. 토양 미세형태분석 결과, 내부 흑색토층은 탄화물이 집적된 층으로 보이며 탄화 가 비교적 가까운 곳에서 일어났을 가능성을 시사한다. 아마도 지붕이나 벽체를 비롯한 상부 구조물 이 탄화되어 집적된 층일 가능성이 높다. 한편 100호 주거지의 규소체분석 결과, 중간 흑색토층 및 상부 퇴적토에서 벼와 조의 규소체가 다량으로 확인되었다. 그리고 사초과 식물의 규소체와 해면동물 골편이 출토된 것으로 보아 저지대(예, 수전) 토양을 벽체 등의 건축재로 사용했던 것으로 보인다. 또 한, 내부 흑색토층이 보이는 주거지와 수혈유구는 연접한 경우가 많아, 화재에 의한 탄화물이 주거지 와 인근 수혈 내부로 흘러 들어간 것으로 생각된다. 이를 종합하여 보면 일부 주거지는 사용이 중지된 이후, 기둥과 같은 주요 건축재를 해체하여 반출한 다음 재활용이 어려운 나머지 잔존 구조물을 소각 했던 것으로 보인다. 그리하여 탄화물이 집적되어 수혈 중간부에 흑색토층을 생성했던 것으로 추정된 다. 본 연구에서는 토양 미세형태분석과 규소체분석이 상호보완적으로 함께 수행되어 해석의 지평을 넓힐 수 있었다.

PURPOSES : Roller-compacted concrete pavement (RCCP) is a superstiff-consistency concrete pavement that exhibits excellent strength development owing to a hydration reaction and interlocking aggregates owing to the roller compaction. A zero-slump concrete mixture is generally used. Hence, it is important to control the consistency of the RCCP mixture to prevent the deterioration of the construction quality (such as material separation during paving). The workability of the RCCP is characterized by its consistency and controlled by the Vebe time, whereas a conventional concrete pavement is controlled based on the slump test. The consistency of the RCCP changes over time after concrete mixing owing to delivery, construction time delays, etc. Thus, it is necessary to use the optimum Vebe time to achieve the best construction quality. Therefore, this study aims to develop a Vebe time prediction model for efficiently controlling the consistency of RCCPs according to random time variations. METHODS : A Vebe time prediction model was developed using a multiple linear regression analysis. A dataset of 131 samples was used to develop the model. The collected data consisted of variables with large potential effects on the consistency of the RCCP, such as the water-cement ratio (W/C), sand/aggregate ratio (S/a), water content (ω), water content per unit volume (W), cement (C), fine aggregate (S), coarse aggregate (G), water reducing admixtrue (PNS), air-entraining admixture (AE), delay time (T), air temperature (TEM), and humidity (HUM). In the multiple linear regression analysis, the mentioned parameters were used as the independent variables, and the Vebe time was the dependent variable. The Vebe time prediction models were evaluated by considering the adjusted R2 and p-values. The selection of the model was based on the largest R2 value and an acceptable p-value (p<0.05). RESULTS : The Vebe time prediction model achieved an adjusted R2 value of 64.14% with a significance level (p-value) of less than 0.05. This shows that the predictive model is adequately described for the dependent variable, and that the model is suitable for Vebe time predictions. Moreover, the significance level of the independent variables is less than 0.05, indicating significant effects on the Vebe time (i.e., the dependent variable). CONCLUSIONS : The Vebe time prediction model developed in this study can be used to estimate Vebe times with an R2 of 63.33% between the measured and predicted values. The proposed Vebe time prediction model is expected to be effectively utilized for the quality control of RCCP mixtures. Moreover, it is expected to contribute to achieving good RCCP construction quality.

Ethyl formate (EF) is a potent fumigant replacing methyl bromide. The use of EF is limited to a quarantine process. Appling EF to agricultural field as a safe insecticide in greenhouse give us valuable benefits including less residual concern. In this regard, residual pattern after EF fumigation in greenhouse should be undertaken. In the previous study, we have established agricultural control concentration of EF to control pests in a greenhouse. EF was fumigated at 5 g m-3 level for 2 h. The concentration of EF inside a greenhouse was analyzed to be 4.1-4.3 g m-3 at 30 min after fumigation. To prepare an analytical method for residues in cucumber crops and soil in the greenhouse, the limit of detection (LOD) of the method was 100 ng g-1 and the limit of quantitation (LOQ) of this method was 300 ng g-1. R2 values of calibration curves for crops and soil were 0.991-0.997. In samples collected immediately after ventilation, EF concentration was determined to be below LOQ level. In addition, EF level was below LOQ in samples collected at 3 h after ventilation except that leaf samples of melon during the flowering period showed a level of 1,068.9 ng g-1. Taken together, these results indicate that EF used in quarantine can be applied to agricultural fields without residual issue as an effective fumigant for insect pest control.