• Title/Summary/Keyword: 공학적 문제해결

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Evaluation of Nutritional Safety for the Herbicide-Resistant Rice in Growing Male Rats (성장기 흰쥐에서 제초제 저항성 쌀의 급여에 대한 영양적 안전성 평가)

  • 이성현;박홍주;조소영;전혜경;박용환;정미혜;박선희
    • Journal of Nutrition and Health
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    • v.36 no.10
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    • pp.1030-1035
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    • 2003
  • This study was conducted to evaluate the safety of herbicide-resistant rice, a genetically modified organism (GMO) developed by the Rural Development Administration, in Sprague-Dawley rats. The nutrient content of herbicide-resistant polished and brown cooked rice was compared with that of conventional Ilpum polished and brown cooked rice to assess composition equivalence. Compositional analysis was performed to measure proximates, fiber, and minerals before animal feeding. Growing male rats were fed one of the following four diets for six weeks: Ilpum polished cooked rice (IP) and Ilpum brown cooked rice (IB) as a non-GMO and herbicide-resistant polished cooked rice (GP) and brown cooked rice (GB) as a GMO. We checked clinical symptoms (anorexia, salivation, diarrhea, polyuria, anuria, fecal change) every day, food intake, change of body weight twice a week, and serum biochemistry and organ weights after 6 weeks of experimental feeding among the four groups. Nutrient content of the herbicide-resistant rice was similar to that of the non-transgenic control and was within the published range observed for non-transgenic rice. We could not find any significant difference in the above-mentioned items as the index to be checked in the animals fed the GMO. These results suggest that the nutrient content of genetically modified herbicide-resistant rice is compositionally equivalent to that of conventional Ilpum rice and that growing male rats fed herbicide-resistant rice are no different from those fed Ilpum rice, non-GMO for 6 weeks.

Using Topology Optimization, Light Weight Design of Vehicle Mounted Voltage Converter for Impact Loading (위상 최적화 기법을 이용한 충격하중에 대한 차량 탑재형 전력변환장치의 마운트 경량화 설계)

  • Ko, Dong-Shin;Lee, Hyun-Kyung;Hur, Deog-Jae
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.6
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    • pp.353-358
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    • 2018
  • In this study, it is describe to an optimization analysis process for the weight reduction of the voltage converter in the electric vehicle charging systems. The optimization design is a technique that finds the optimal material distribution under a given material quantity constraint by combining the design sensitivity with the material properties and the mathematical optimization. Among the topology optimization, a lightweight design is performed by a solid isotropic material with penalization with simple formula and well-convergence. The lightweight design consists of three steps. As a first step, a finite element model for the basic design of the on-board voltage converter was constructed and static analysis was performed on the load. In the second step, the optimum shape is obtained for the lightweight by performing the topology optimization using the solid isotropic material with penalization applying the stiffness coefficient of the isotropic material to the static analysis result. As a final step, impact analysis was performed by applying a half-sinusoidal pulse shape impact load which satisfies the impact test standard of the vehicle-mounted part with respect to the optimum shape. In the topology optimization, the design domain was defined as the mounting bracket area, and the design technology was finally achieved by optimizing the mounting bracket to achieve a weight reduction of 20% over the basic design.

A study on the degree of aging recognition of firefighters and countermeasures(focus on firefighters in Jeollanam-do) (소방공무원의 고령화 인식정도와 대응방안에 관한 연구(전라남도 소방공무원을 중심으로))

  • Ha, Kang Hun;Kim, Jae Ho;Choi, Jae Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.398-407
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    • 2021
  • Firefighters (who are responsible for people's safety) have one of the jobs that are expected to have problems due to aging in the workforce. An increase in the average age of firefighters can lead to serious social problems. The aim of this study is to survey firefighters in Jeollanam-do about their awareness of aging in firefighters, and to propose a plan to prepare them for aging through investigation and analysis of work problems that may occur due to an aging workforce. The survey shows that the higher the age group, the higher the awareness of aging firefighters, and the higher the total work experience and internal/external work experience, the higher the awareness of aging. As a plan to solve various problems that may arise from aging in firefighters, regular operation of physical fitness promotion programs, field work, job rotation, and managerial measures (such as a change of position to an administrative department) are prepared, and drone or robot technology is used. These solutions include the introduction of applied high-tech technologies to firefighting activities, establishment of retirement management policies, and preparation of plans to revitalize the connection to private employment. In order to maximize the applicability of the field, government institutional plans and preparations are essential.

A Study of the Scene-based NUC Using Image-patch Homogeneity for an Airborne Focal-plane-array IR Camera (영상 패치 균질도를 이용한 항공 탑재 초점면배열 중적외선 카메라 영상 기반 불균일 보정 기법 연구)

  • Kang, Myung-Ho;Yoon, Eun-Suk;Park, Ka-Young;Koh, Yeong Jun
    • Korean Journal of Optics and Photonics
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    • v.33 no.4
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    • pp.146-158
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    • 2022
  • The detector of a focal-plane-array mid-wave infrared (MWIR) camera has different response characteristics for each detector pixel, resulting in nonuniformity between detector pixels. In addition, image nonuniformity occurs due to heat generation inside the camera during operation. To solve this problem, in the process of camera manufacturing it is common to use a gain-and-offset table generated from a blackbody to correct the difference between detector pixels. One method of correcting nonuniformity due to internal heat generation during the operation of the camera generates a new offset value based on input frame images. This paper proposes a technique for dividing an input image into block image patches and generating offset values using only homogeneous patches, to correct the nonuniformity that occurs during camera operation. The proposed technique may not only generate a nonuniformity-correction offset that can prevent motion marks due to camera-gaze movement of the acquired image, but may also improve nonuniformity-correction performance with a small number of input images. Experimental results show that distortion such as flow marks does not occur, and good correction performance can be confirmed even with half the number of input images or fewer, compared to the traditional method.

Research on the Urban Green Space Connection Paths forthe Enhancement of Ecological Function - Focused on Suwon - (녹지축의 생태적 기능 강화를 위한 도시녹지 연결경로 도출 연구 - 수원시 대상 -)

  • Choi, Jaeyeon;Kim, Suryeon;Park, Chan;Song, Wonkyong;Jung, Kyungmin;Kim, Eunyoung
    • Journal of Environmental Impact Assessment
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    • v.31 no.4
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    • pp.201-213
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    • 2022
  • Creation and administration of green space are emphasized to solve the environmental problem and the management of green space in urban area. Urban area with high development pressure faces green space fragmentation, so the planned approach is needed to improve the continuity of green space. However, the current institutional green axis, used to enhance continuity of urban space is merely an abstract concept under the master plan so that is not a consistent framework for urban green continuity providing no detailed information such as position and path. Therefore, in order to consistently manage green space in continuous point of view, it is insufficient not being connected to each individual green space development projects. This study proposes a method for finding the connection path to enhance urban green space continuity. This proposed method consists of two phases. First phase is finding nodes to connect current green space and second is to calculate the least cost path. We calculate connection cost using NDMI (Normalized Difference Moisture Index), impervious ratio and official land cost, applying to Suwon city and potential greening site that was planned in official master plan. According to the results, we confirm a possibility of finding a cost-effective connection path with detailed spatial information instead of unrealistic abstract concepts and discuss worth applying to a legally plan and policy.

A Study on the Application Method of Artificial Injection Test according to the Hydraulic Conductivity of Aquifer (대수층 수리지질특성에 따른 인공함양시험 적용 방법에 관한 연구)

  • Chae, Dong-Seok;Choi, Jin-O;Jeong, Hyeon-Cheol;Kim, Chang-Yong
    • The Journal of Engineering Geology
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    • v.31 no.4
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    • pp.589-601
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    • 2021
  • Artificial recharge technology is a method for solving problems such as groundwater level drop and ground subsidence caused by groundwater withdrawal. This study investigated the applicability of using the hydraulic conductivity of an aquifer to predict injection test results for aquifer restoration. Pumping and injection tests were performed under the same conditions as those for the artificial injection facility located in Icheon, Gyeonggi-do. The hydraulic conductivity of the aquifer, which plays a decisive role in restoring the groundwater level, was derived from the pumping test. A numerical model of a simplified on-site aquifer was constructed, and a transient analysis was applied with the same conditions as the pumping test. The correlation between the measured and the resulting model values is strong (R2 = 0.78). The injection test was performed in a sedimentary layer composed of silt sand and clay sand. From the results of the injection test, an empirical formula was derived using Theim's formula, which is a common well analysis solution to determine the parameters of the aquifer from time-level data. The model values from the empirical formula have a high degree of correlation (R2 = 0.99) with measured values. Under specific conditions, for areas where it is difficult to conduct an injection test, the formula from this study, which relies on the hydraulic conductivity of the aquifer determined through the pumping test, may be used to predict reliable injection rates for groundwater restoration.

A Study on the Use of Contrast Agent and the Improvement of Body Part Classification Performance through Deep Learning-Based CT Scan Reconstruction (딥러닝 기반 CT 스캔 재구성을 통한 조영제 사용 및 신체 부위 분류 성능 향상 연구)

  • Seongwon Na;Yousun Ko;Kyung Won Kim
    • Journal of Broadcast Engineering
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    • v.28 no.3
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    • pp.293-301
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    • 2023
  • Unstandardized medical data collection and management are still being conducted manually, and studies are being conducted to classify CT data using deep learning to solve this problem. However, most studies are developing models based only on the axial plane, which is a basic CT slice. Because CT images depict only human structures unlike general images, reconstructing CT scans alone can provide richer physical features. This study seeks to find ways to achieve higher performance through various methods of converting CT scan to 2D as well as axial planes. The training used 1042 CT scans from five body parts and collected 179 test sets and 448 with external datasets for model evaluation. To develop a deep learning model, we used InceptionResNetV2 pre-trained with ImageNet as a backbone and re-trained the entire layer of the model. As a result of the experiment, the reconstruction data model achieved 99.33% in body part classification, 1.12% higher than the axial model, and the axial model was higher only in brain and neck in contrast classification. In conclusion, it was possible to achieve more accurate performance when learning with data that shows better anatomical features than when trained with axial slice alone.

An Analysis on Indicators of Water Taxi User Service in Seoul Using Importance Performance Analysis (IPA) (중요도-만족도 분석을 활용한 서울시 수상택시 이용자 서비스지표 분석)

  • Kim, Tae Ho;Ha, Jong Moon;Lim, Jong Moon;Park, Je Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5D
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    • pp.587-595
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    • 2009
  • Since October 11th, 2007, water taxi service in Han River has been operated for commuting and sightseeing. However, it is less popularized than expected because of economical problem and accessibility. Therefore, this paper develops service estimation items for water taxi based upon literature review on public transportation. It also conducts survey questionnaire and IPA (Importance Performance Analysis) Analysis to analyze service characteristics of water taxi users and provide several implications. The results are follows: First, economical problem should be solved out as showed in the 'main improvement' item. Second, accessibility, informativeness and convenience in the 'required improvement' item, and security and punctuality in the 'keep up the good work' item are presented. Third, kindness and soundness are showed in the 'the maintenance of current situation' item. All in all, if municipal considers economical problem, accessibility, informativeness, and convenience as it improves water tax service, it will make it possible to attract more water taxi users.

Generation of Daily High-resolution Sea Surface Temperature for the Seas around the Korean Peninsula Using Multi-satellite Data and Artificial Intelligence (다종 위성자료와 인공지능 기법을 이용한 한반도 주변 해역의 고해상도 해수면온도 자료 생산)

  • Jung, Sihun;Choo, Minki;Im, Jungho;Cho, Dongjin
    • Korean Journal of Remote Sensing
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    • v.38 no.5_2
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    • pp.707-723
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    • 2022
  • Although satellite-based sea surface temperature (SST) is advantageous for monitoring large areas, spatiotemporal data gaps frequently occur due to various environmental or mechanical causes. Thus, it is crucial to fill in the gaps to maximize its usability. In this study, daily SST composite fields with a resolution of 4 km were produced through a two-step machine learning approach using polar-orbiting and geostationary satellite SST data. The first step was SST reconstruction based on Data Interpolate Convolutional AutoEncoder (DINCAE) using multi-satellite-derived SST data. The second step improved the reconstructed SST targeting in situ measurements based on light gradient boosting machine (LGBM) to finally produce daily SST composite fields. The DINCAE model was validated using random masks for 50 days, whereas the LGBM model was evaluated using leave-one-year-out cross-validation (LOYOCV). The SST reconstruction accuracy was high, resulting in R2 of 0.98, and a root-mean-square-error (RMSE) of 0.97℃. The accuracy increase by the second step was also high when compared to in situ measurements, resulting in an RMSE decrease of 0.21-0.29℃ and an MAE decrease of 0.17-0.24℃. The SST composite fields generated using all in situ data in this study were comparable with the existing data assimilated SST composite fields. In addition, the LGBM model in the second step greatly reduced the overfitting, which was reported as a limitation in the previous study that used random forest. The spatial distribution of the corrected SST was similar to those of existing high resolution SST composite fields, revealing that spatial details of oceanic phenomena such as fronts, eddies and SST gradients were well simulated. This research demonstrated the potential to produce high resolution seamless SST composite fields using multi-satellite data and artificial intelligence.

A Study on Criteria for the Credit Approval of Nationally Authorized Civil Qualifications (국가공인 민간자격 학점인정 기준에 관한 방안 연구)

  • Shin Myong-Hoon;Park Jong-Sung
    • Journal of Engineering Education Research
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    • v.7 no.2
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    • pp.5-21
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    • 2004
  • The study aims to propose plans to give credit approval to those who obtain authorized civil qualifications, in accordance with the enforcement regulations under the Clause 7, Article 4 of $\ulcorner$the law on credit approval and others$\lrcorner$. Preceding studies on the grounds and principles of credit approval, analyses on the related references and materials, and surveys asking the managers of authorized civil qualifications their opinion over giving credit approval to authorized civil qualifications were conducted as the methodology of this study. Besides, a conference inviting experts from the relevant fields was held to specifically overview the contents and levels to be examined by qualification items, to conduct a face-to-face survey on directions to take in the credit approval of authorized civil qualifications, and to analyze the level and the degree of the difficulty of questions in the examinations of authorized civil qualifications. The contents and the level of credit approval in this study are as follows. For the authorized civil qualification items unable to formulate criteria in accordance with the principles of credit approval taken in the national technique qualification and other national qualifications, two factors were put under consideration for setting the level of the credit approval. First, the level and scope of work were investigated. Second, the content of qualification was compared with the course work of college. The degree of difficulty in the scope and performance of work was reviewed by specialized qualification and general qualification, respectively. Specialized qualification indicates whether or not the required knowledge and technique are acquired for performing duty in specific work fields. It falls into service fields and qualification items except qualification items on general clerical work of the national technique qualification and other national qualifications. To the contrary, general qualification is to prove the degree of acquisition of knowledge and technique for improving the basic competencies throughout diverse types of occupations. It includes competencies to verify language proficiency, mathematical and statistical capacity, problem settlement, negotiation and communication skills. When the authorized civil qualification came under the specialized qualification, the level of qualification was determined in comparison with the level of work of national qualifications. In the case of the general qualification, the credit to be approved was settled by conducting a comparative analysis on the course work of college.