• 한국통신학회논문지
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• 제25권6B호
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• pp.1100-1105
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• 2000

현대의 레이더 펄스 압축기술로 가장 널리 사용되고 있는 방식은 바커코드를 사용하여 matched filter로 레이더 신호를 처리하는 상관처리(correlation processing)이다. 그러나 이 방식의 경우 탐지 감도를 높여 주는 장점이 있지만, 환경에 따라서 range-sidelobe가 발생하여 레이더의 성능을 낮추게 된다. 본 논문에서는 상관처리방식에 추가적인 처리로 sidelobe를 제거하는 최적처리 방법을 제안하고 Doppler shift가 존재할 때의 성능을 평가한다. 그리고 제안된 알고리즘 환경에서 최적의 이진 코드를 개발하고 이를 Barker 코드를 사용한 전통적인 상관처리방식의 경우와 비교.분석한다. 도플러 변이가 존재할 때, 최적 코드를 사용하여 최적 처리하는 방식이 바커코드를 사용한 전통적인 처리방법보다 레이더의 성능을 향상시킴을 보여줄 것이다.

• 한국멀티미디어학회논문지
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• 제17권10호
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• pp.1182-1188
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• 2014

Recently, the research on database outsourcing has been actively done with the popularity of cloud computing. However, because users' data may contain sensitive personal information, such as health, financial and location information, the data encryption methods have attracted much interest. Existing data encryption schemes process a query without decrypting the encrypted databases in order to support user privacy protection. On the other hand, to efficiently handle the large amount of data in cloud computing, it is necessary to study the distributed index structure. However, existing index structure and query processing algorithms have a limitation that they only consider single-column query processing. In this paper, we propose a grid-based multi column indexing scheme and an encrypted query processing algorithm. In order to support multi-column query processing, the multi-dimensional index keys are generated by using a space decomposition method, i.e. grid index. To support encrypted query processing over encrypted data, we adopt the Hilbert curve when generating a index key. Finally, we prove that the proposed scheme is more efficient than existing scheme for processing the exact and range query.

• 한국약용작물학회지
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• 제18권2호
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• pp.98-104
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• 2010

Eleuthero(Eleutherococcus senticosus Maxim.) cortex is well known as a herb medicine for tonic. This study was performed to improve the quality of dried E. senticosus cortex. Investigation of quality factor and contents of efficient compounds under different steaming times and drying methods were performed to determine the proper processing and drying conditions of Eleuthero cortex harvested on March in annual stems. The proper steaming time for peeling bark to make high quality Eleuthero cortex took less than 20 mins. Eleutheroside B and E contents among drying methods were significantly different at 5% level DMRT. The $50^{\circ}C$ heat drying was the most advisable condition for drying, when drying and keeping contents of effective compounds.

• 소성∙가공
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• 제30권1호
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• pp.22-26
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• 2021

The present study demonstrated the effects of processing variable and alloying elements on the processing window of austempered cast iron, one of the heat-treatable cast irons, in order to elucidate the relation between heat treatment and microstructure in terms of time and temperature. Such microstructure is strongly affected by austenitizing conditions and alloying elements. The size of processing window tends to increase initially with increasing austenitizing temperature from 1123 to 1173 K, followed by a decline in the reverse direction between 1173 and 1223 K. Thus, the optimized processing window with large frame was found at an austenitizing temperature of 1173 K. To determine the effect of Sn addition, the processing window in the sample was created by the addition of 0.08 wt.% Sn, which appeared larger than that without Sn and with 0.06 wt.% Sn.

• International journal of advanced smart convergence
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• 제8권4호
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• pp.194-199
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• 2019

As the performance of the system increases, more parallelized data is being processed than single processing of data. Today's cpu structure has been developed to leverage multicore, and hence data processing methods are being developed to enable parallel processing. In recent years desktop cpu has increased multicore, data is growing exponentially, and there is also a growing need for data processing as artificial intelligence develops. This neural network of artificial intelligence consists of a matrix, making it advantageous for parallel processing. This paper aims to speed up the processing of the system by using raspberrypi to implement the cluster building and parallel processing system against the backdrop of the foregoing discussion. Raspberrypi is a credit card-sized single computer made by the raspberrypi Foundation in England, developed for education in schools and developing countries. It is cheap and easy to get the information you need because many people use it. Distributed processing systems should be supported by programs that connected multiple computers in parallel and operate on a built-in system. RaspberryPi is connected to switchhub, each connected raspberrypi communicates using the internal network, and internally implements parallel processing using the Message Passing Interface (MPI). Parallel processing programs can be programmed in python and can also use C or Fortran. The system was tested for parallel processing as a result of multiplying the two-dimensional arrangement of 10000 size by 0.1. Tests have shown a reduction in computational time and that parallelism can be reduced to the maximum number of cores in the system. The systems in this paper are manufactured on a Linux-based single computer and are thought to require testing on systems in different environments.

• 한국항행학회논문지
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• 제18권4호
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• pp.401-408
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• 2014

하둡(Hadoop)은 맵리듀스(MapReduce) 분산처리 프로그래밍 모델과 HDFS(Hadoop distributed file system) 분산 파일시스템으로 구성된다. 하둡은 빅데이터 처리에 적합한 프레임워크로서, 대량의 스몰파일 처리에 문제점이 있다. 하둡에서 대량의 스몰파일 처리는 하나의 파일마다 매퍼가 생성되며, 파일의 메타정보를 저장하기 위해 많은 메모리가 필요한 문제점이 있다. 본 논문은 하둡 플랫폼에서 다양한 방법으로 대량의 스몰파일 처리방법을 비교 검토하였다. 일반 압축은 데이터의 크기와 상관없이 하나의 매퍼로 처리해야 하기 때문에, 하둡 처리 포맷으로 적절하지 않다. 시퀀스 와 하둡 아카이브 파일의 처리는 스몰파일을 압축 및 병합을 통해 네임노드의 메모리 문제가 제거되었다. 하둡 아카이브 파일은 스몰파일의 병합시간이 시퀀스 파일보다 빠른 속도를 보였다. CombineFileInputFormat 클래스를 이용한 처리는 병합과정이 필요 없으며, 빅데이터 처리방법과 유사한 속도를 보였다.

• 한국실내디자인학회논문집
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• 제21권3호
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• pp.22-30
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• 2012

Nowadays the issue of environmental pollution and ecological destruction is not a simple issue but an important issue to be continuously considered. It is deemed that a study for recycled new materials is immediately required and this study is to analyze features and processing methods of new materials which can be used to interior space. We found the recycled new materials used for space through researching various web sits. And then we analyzed what the base materials are and classified that base materials are whether natural or artificial of the recycled materials. We classified processing methods of the recycled new materials after researching general processing methods. The result of this study would be an important material to the research and development of new finishing materials with consideration of environment and to the research for a guideline of applicable new materials. The results of this study are as follows : First, we could classify widely 2 categories into natural material and artificial material and then 10 subcategories into metal, glass, wood, rubber, stone, plastic, leather or fabric, ceramic, concrete and so on, and analyzed that which material is mostly used and whether it is single material or multiple material. In order to analyze the feature of processing method. Second, we could classify into 4 categories such as junction, surface process, molding, and insert, and found out which processing method is applied based on objects of research. Third, as an analysis result of the recycled new material feature, in order to develop various new materials, it is required to study on combination and application of 2 materials or more rather than single material. Four, as a analysis result of the processing method feature, I would like to suggest that development and application of various processing methods are required. Especially, it is necessary to grope for a way to develop new functional materials for interior space through a systemic research and analysis of processing method of other fields. Furthermore, a way to reuse recycled new materials should be considered in a stage of selection and application of processing method.

• Earthquakes and Structures
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• 제3권3_4호
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• pp.341-363
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• 2012

The spectral representation method is a quick and versatile tool for the generation of spatially variable, response-spectrum-compatible simulations to be used in the nonlinear seismic response evaluation of extended structures, such as bridges. However, just as recorded data, these simulated accelerations require processing, but, unlike recorded data, the reasons for their processing are purely numerical. Hence, the criteria for the processing of acceleration simulations need to be tied to the effect of processing on the structural response. This paper presents a framework for processing acceleration simulations that is based on seismological approaches for processing recorded data, but establishes the corner frequency of the high-pass filter by minimizing the effect of processing on the response of the structural system, for the response evaluation of which the ground motions were generated. The proposed two-step criterion selects the filter corner frequency by considering both the dynamic and the pseudo-static response of the systems. First, it ensures that the linear/nonlinear dynamic structural response induced by the processed simulations captures the characteristics of the system's dynamic response caused by the unprocessed simulations, the frequency content of which is fully compatible with the target response spectrum. Second, it examines the adequacy of the selected estimate for the filter corner frequency by evaluating the pseudo-static response of the system subjected to spatially variable excitations. It is noted that the first step of this two-fold criterion suffices for the establishment of the corner frequency for the processing of acceleration time series generated at a single ground-surface location to be used in the seismic response evaluation of, e.g. a building structure. Furthermore, the concept also applies for the processing of acceleration time series generated by means of any approach that does not provide physical considerations for the selection of the corner frequency of the high-pass filter.

• 자동차안전학회지
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• 제13권2호
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• pp.35-41
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• 2021

In this study, improved path tracking control algorithm based on pure pursuit algorithm is newly proposed by using improved lane detection algorithm through real time post-processing with interpolation methodology. Since the original pure pursuit works well only at speeds below 20 km/h, the look-ahead distance is implemented as a sigmoid function to work well at an average speed of 45 km/h to improve tracking performance. In addition, a smoothing filter was added to reduce the steering angle vibration of the original algorithm, and the stability of the steering angle was improved. The post-processing algorithm presented has implemented more robust lane recognition system using real-time pre/post processing method with deep learning and estimated interpolation. Real time processing is more cost-effective than the method using lots of computing resources and building abundant datasets for improving the performance of deep learning networks. Therefore, this paper also presents improved lane detection performance by using the final results with naive computer vision codes and pre/post processing. Firstly, the pre-processing was newly designed for real-time processing and robust recognition performance of augmentation. Secondly, the post-processing was designed to detect lanes by receiving the segmentation results based on the estimated interpolation in consideration of the properties of the continuous lanes. Consequently, experimental results by utilizing driving guidance line information from processing parts show that the improved lane detection algorithm is effective to minimize the lateral offset error in the diverse maneuvering roads.

• 한국정보통신학회논문지
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• 제25권6호
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• pp.825-833
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• 2021

비행시험에서 비행체의 경우 실시간으로 빠르게 이동하므로 비행체 상태를 파악하기 위하여 사용되는 계측/측정장비들의 데이터는 비행시험통제시스템들에 필요한 형태로 처리되고 송신되는 것이 실시간으로 이루어지는 것이 중요하다. 그래서 통제컴퓨터 자료처리시스템에서 발생하는 원격측정자료 처리시간의 감소 및 처리 주기의 향상을 통하여 계측레이더/원격측정장비 연동자료 처리, 비행안전 판단시스템, 비상종료 송신시스템 등에 연동자료 및 안전판단 정보를 현재보다 빠르고 유연하게 제공하기 위해 현 운용중인 원격측정자료처리시스템의 PCM 데이터와 레이더 정보를 동시에 수신/처리할 수 있는 자료처리 소프트웨어를 탑재하여 독립 운용이 가능한 PCM 자료처리시스템 을 개발하였다. 본 논문에서는 기존 시스템을 보완하여 개발된 PCM 자료처리시스템의 전체적인 구조부터 소프트웨어 기능을 세부적으로 분류하여 중점적으로 설명하고 있다. 또한, PCM 자료처리시스템은 시스템 안정화 및 시험운영을 통하여 점차 보완해 나갈 것이다.