• Journal of Drive and Control
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• v.19 no.1
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• pp.43-50
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• 2022

The aim of this study was to conduct basic research on the development of a dual-clutch transmission(DCT) and automatic transmission for agricultural tractors. The DCT layout and the DCT simulation model were developed using commercial software. Power transmission efficiency of the DCT and component power loss were analyzed to verify the developed simulation model. Power loss analysis of the components was conducted according to previous studies and ISO(International Organization for Standardization) standards. The power transmission efficiency of the DCT simulation model was 68.4-91.5% according to the gear range. The power loss in the gear, bearing, and clutch DCT system components was 0.75-1.49 kW, 0.77-2.99 kW, and 5.24-10.52 kW, respectively. The developed simulation model not include the rear axle, differential gear, final reduction gear. Therefore actual power transmission efficiency of DCT will be decreased. In a future study, an actual DCT can be developed through the simulation model in this study, and optimization design of DCT can be possible by comparing simulation results and actual vehicle test.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.39-48
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• 2014

The speed of aging society is increasingly getting faster in Korea. Currently, there are over one million elderly living alone, which represents more than 19% of the total elderly in Korea. Although various policies and research have been implemented for caring the elderly living alone, there have been obvious limitations in realization of the caring system due to inconvenience, privacy violation, difficult operation and maintenance. Therefore, the objective of this study is to develop a method and a prototype system to monitor safety of elderly living alone by using energy usage information of automatic meter reading device. The proposed system is expected to improve or resolve the existing limitations and to provide 24 hour monitoring and early detection of death for the elderly living alone without adding staffs for operation and maintenance in a more effective and economic way.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.3
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• pp.199-206
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• 2023

This study utilizes deep learning algorithms to automatically classify construction waste into three categories: wood waste, plastic waste, and concrete waste. Two models, VGG-16 and ViT (Vision Transformer), which are convolutional neural network image classification algorithms and NLP-based models that sequence images, respectively, were compared for their performance in classifying construction waste. Image data for construction waste was collected by crawling images from search engines worldwide, and 3,000 images, with 1,000 images for each category, were obtained by excluding images that were difficult to distinguish with the naked eye or that were duplicated and would interfere with the experiment. In addition, to improve the accuracy of the models, data augmentation was performed during training with a total of 30,000 images. Despite the unstructured nature of the collected image data, the experimental results showed that VGG-16 achieved an accuracy of 91.5%, and ViT achieved an accuracy of 92.7%. This seems to suggest the possibility of practical application in actual construction waste data management work. If object detection techniques or semantic segmentation techniques are utilized based on this study, more precise classification will be possible even within a single image, resulting in more accurate waste classification

• Tunnel and Underground Space
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• v.33 no.4
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• pp.281-298
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• 2023

Continuous research efforts are being devoted to unmanned mobile platforms for lunar exploration. There is an ongoing demand for real-time information processing to accurately determine the positioning and mapping of areas of interest on the lunar surface. To apply deep learning processing and analysis techniques to practical rovers, research on software integration and optimization is imperative. In this study, a foundational investigation has been conducted on real-time analysis of virtual lunar base construction site images, aimed at automatically quantifying spatial information of key objects. This study involved transitioning from an existing region-based object recognition algorithm to a boundary box-based algorithm, thus enhancing object recognition accuracy and inference speed. To facilitate extensive data-based object matching training, the Batch Hard Triplet Mining technique was introduced, and research was conducted to optimize both training and inference processes. Furthermore, an improved software system for object recognition and identical object matching was integrated, accompanied by the development of visualization software for the automatic matching of identical objects within input images. Leveraging satellite simulative captured video data for training objects and moving object-captured video data for inference, training and inference for identical object matching were successfully executed. The outcomes of this research suggest the feasibility of implementing 3D spatial information based on continuous-capture video data of mobile platforms and utilizing it for positioning objects within regions of interest. As a result, these findings are expected to contribute to the integration of an automated on-site system for video-based construction monitoring and control of significant target objects within future lunar base construction sites.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.73-80
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• 2009

Recently in order to mange better life quality much effort was spent for environmental-friendly urban development project and environmental restoration project. During these projects, there should be deep understanding about atmospheric environment change analysis and long term monitoring so that it would be helpful for better environment promotion such as heat island mitigation effect and wind way construction. In this study, the surface temperature environment change between before and after Cheonggye Stream Restoration Project was mapped and analyzed by using ASTER(Advanced Spaceborne Thermal Emission Reflection Radiometer) TIR(Thermal Infrared) satellite imagery and finally the fact, that the heat island effect was mitigated, was clarified. For this study, the correlation analysis was conducted through comparing the difference between atmosphere temperature of AWS(Automatic Weather System) and surface temperature of ASTER. Furthermore, this study will be the infrastructure of urban meteorology model development by understanding surface temperature pattern change and executing quantitative analysis of heat island.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.63-70
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• 2013

In previous research, we suggested a business process structured query language(BPSQL) for information extraction and retrieval in the business process framework, and used an existing query language with the tablization for each layer within the framework, but still had a problem to manually build with the specification of each layer information of BFP. To solve this problem, we suggest automatically to build the schema based business process model with model-to-text conversion technique. This procedure consists of 1) defining each meta-model of the entire structure and of database schema, and 2) also defining model transformation rules for it. With this procedure, we can automatically transform from defining through meta-modeling of an integrated information system designed to the schema based model information table specification defined of the entire layer each layer specification with model-to-text conversion techniques. It is possible to develop the efficiently integrated information system.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.401-408
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• 2005

Recently shield TBM tunnellings are being applied to subway construction in Korean cities. Generally these kinds of tunnellings have the problems in the stability of ground such as subsidence because urban subway is constructed in the shallow depth. A sinkhole occurred on the road just above the tunnel during tunneling in Kwangju, so a survey for upper layer of the tunnel was needed. But conventional Ground Probing Radar can't be applicable due to the presence of steel-mesh screen in the shield segment, so no existent geophysical method is applicable in this site. Because the outer surface of each shield segment is electrically insulated, dipole-dipole resistivity method which is popular in engineering site investigation, was tried to this survey for the first time. Specially manufactured flexible ring-type electrodes were installed into the grouting holes at an interval of 2.4 m on the ceiling. The K-Ohm II system which has been developed by KIGAM and tested successfully in many sites, was used in this site. The system consists of 1000Volt-1Ampere constant-current transmitter, optically isolated 24 bit sigma-delta A/D conversion receiver - maximum 12 channel simultaneous measurements, and graphical automatic acquisition software for easy data quality check in real time. Borehole camera logging with circular white LED lighting was also done to investigate the state of the layer. Measured resistivity data lack of some stations due to failing opening lids of holes, shows general high-low trend well. The dipole-dipole resistivity inversion results discriminate (1) one approximately 4 meter diameter cavity (grouted but incompletely hardened, so low resistivity - less than $30{\Omega}m$), (2) weak zone (100-200${\Omega}m$), and (3) hard zone (high resistivity - more than 1000${\Omega}m$) very well for the distance of 320 meters. The 2-D inversion neglects slight absolute 3-D effect, but we can get satisfactory and useful information. Acquired resistivity section and video tapes by borehole camera logging will be reserved and reused if some problem occurs in this site in the future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1235-1240
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• 2010

Wire-woven Bulk Kagome (WBK) is fabricated by assembling helically formed wires in six directions. To date, WBK samples have been assembled manually. For industrial application, the assembly process must be automated. Furthermore, if WBK is to be fabricated using flexible wires that cannot maintain their helical shape during fabrication, a specialized automatic machine, i.e., a loom needs to be developed. In this work, we designed and constructed a loom for fabricating WBKs using flexible wires. This loom is operated by one rotation of the upper plate, two translations of the insertion device, and insertion of wires. So-called "comb devices" are placed between multiple layers of Kagome nets to prevent the wires that are already in place from getting entangled with those that are being inserted. This loom can be also used to fabricate semi-WBKs composed of helically formed wires and rigid straight wires.

• Annual Conference on Human and Language Technology
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• 2007.10a
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• pp.84-90
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• 2007

일반적인 어휘망이 의미 관계에 의한 연결 구조를 중심으로 연구 개발된 것과는 달리, U-WIN은 의미관계를 비롯하여 개념 관계, 형태 관계, 구문 관계 등과 같이 의미 관계의 범위를 확장한 어휘 관계를 적용하여 구축하고 있다. 본 연구에서는 U-WIN의 어휘 관계 중의 하나인 구문관계를 자동으로 구축하는 방법을 제시하고자 한다. 먼저, 용언의 용례에서 문형정보를 기준으로 구문관계를 형성할 수 있는 후보명사를 추출하였으며, 추출한 후보명사는 용언의 세분화된 의미별로 정확하고 다양하게 추출할 수 있었다. 그러나 U-WIN은 다의어의 뜻풀이 하나하나를 개별적인 어휘로 구분하여 구축하였으므로, 어휘 간의 구문관계를 설정하기 위해서는 후보명사의 여러 의미 중에서 하나의 의미로 결정해야 한다. 그래서 본 연구에서는 용례 매칭 규칙, 구문패턴, 의미 유사도 등을 차례로 적용하여 후보명사의 의미를 분별하였으며, 또한 구문패턴의 빈도 정보를 이용하여 용례에 나타나지 않지만 구문관계를 형성할 수 있는 명사를 추출하여 구문관계를 확장하고자 하였다. 이러한 연구는 명사 중심의 어휘망이 용언과의 구문관계 구축을 통해 형태소 분석, 구문 분석, 의미 분석 등에 광범위하게 활용할 수 있는 어휘망의 기반을 다지는 작업이 될 수 있을 것이다.

• 한국지형공간정보학회:학술대회논문집
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• 2002.11a
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• pp.117-122
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• 2002

Change detection is a useful technology that can be applied to various fields, taking temporal change information with the comparison and analysis among multi-temporal satellite images. Especially, change detection that utilizes high-resolution satellite imagery can be implemented to extract useful change information for many purposes, such as the environmental inspection, the circumstantial analysis of disaster damage, the inspection of illegal building, and the military use, which cannot be achieved by lower middle-resolution satellite imagery. However, because of the special characteristics that result from high-resolution satellite imagery, it cannot use a pixel-based method that is used for low-resolution satellite imagery. Therefore, it must be used a feature-based algorithm based on the geographical and morphological feature. This paper presents the system that builds the change map by digitizing the boundary of the changed object. In this system, we can make the change map using manual or semi-automatic digitizing through the user interface implemented with a floating window that enables to detect the sign of the change, such as the construction or dismantlement, more efficiently.