• International Journal of Computer Science & Network Security
• /
• 제23권1호
• /
• pp.33-40
• /
• 2023

Machine-learning techniques are discovering effective performance on data analytics. Classification and regression are supported for prediction on different kinds of data. There are various breeds of classification techniques are using based on nature of data. Threshold determination is essential to making better model for unlabelled data. In this paper, threshold value applied as range, based on min-max normalization technique for creating labels and multiclass classification performed on rainfall data. Binary classification is applied on autism data and classification techniques applied on child abuse data. Performance of each technique analysed with the evaluation metrics.

• 산업경영시스템학회지
• /
• 제21권45호
• /
• pp.57-65
• /
• 1998

This paper addresses the data classification using the induction of decision trees. A weakness of other techniques of induction of decision trees is that decision trees are too large because they construct decision trees until leaf nodes have a single class. Our study include both overcoming this weakness and constructing decision trees which is small and accurate. First, we construct the decision trees using classification threshold and exception threshold in construction stage. Next, we present two stage pruning method using classification threshold and reduced error pruning in pruning stage. Empirical results show that our method obtain the decision trees which is accurate and small.

• 대한산업공학회지
• /
• 제23권4호
• /
• pp.755-767
• /
• 1997

Analyzing autocorrelated data set is still an open problem. Developing on easy and efficient method for severe positive correlated data set, which is common in simulation output, is vital for the simulation society. Bootstrap is on easy and powerful tool for constructing non-parametric inferential procedures in modern statistical data analysis. Conventional bootstrap algorithm requires iid assumption in the original data set. Proper choice of resampling units for generating replicates has much to do with the structure of the original data set, iid data or autocorrelated. In this paper, a new bootstrap resampling scheme is proposed to analyze the autocorrelated data set : the Threshold Bootstrap. A thorough literature search of bootstrap method focusing on the case of autocorrelated data set is also provided. Theoretical foundations of Threshold Bootstrap is studied and compared with other leading bootstrap sampling techniques for autocorrelated data sets. The performance of TB is reported using M/M/1 queueing model, else the comparison of other resampling techniques of ARMA data set is also reported.

• 한국컴퓨터정보학회논문지
• /
• 제20권11호
• /
• pp.1-8
• /
• 2015

Flash memory has advantages in that it is fast access speed, low-power, and low-price. Therefore, they are widely used in electronics industry sectors. However, the flash memory has weak points, which are the limited number of erase operations and non-in-place update problem. To overcome the limited number of erase operations, many wear leveling techniques are studied. They use many tables storing information such as erase count of blocks, hot and cold block indicators, reference count of pages, and so on. These tables occupy some space of main memory for the wear leveling techniques. Accordingly, they are not appropriate for low-power devices limited main memory. In order to resolve it, a wear leveling technique using bit array and Bit Set Threshold (BST) for flash memory. The proposing technique reduces the used space of main memory using a bit array table, which saves the history of block erase operations. To enhance accuracy of cold block information, we use BST, which is calculated by using the number of invalid pages of the blocks in a one-to-many mode, where one bit is related to many blocks. The performance results illustrate that the proposed wear leveling technique improve life time of flash memory to about 6%, compared with previous wear leveling techniques using a bit array table in our experiment.

• 한국음향학회지
• /
• 제39권6호
• /
• pp.585-591
• /
• 2020

적응형 전송 기법은 수중 음향 채널의 상태에 따라 전송 파라미터를 변경하여 전송 및 성능을 향상 시키는 효율적인 방법이다. 본 논문에서는 적응형 전송 기법에서 전송 모드를 결정하기 위한 네 가지 모드와 이의 모드를 검출하기 위한 세 가지 임계값 검출 알고리즘을 제안한다. 송신기에서 정보비트의 크기를 자유롭게 설정하기 위하여 컴볼루션 부호를 사용하였으며, 수신기에서는 성능을 향상시키기 위하여 BCJR 복호 기반 터보등화기법을 적용하였다. 또한 수중 실험을 통해 각 모드에서 성능을 만족하는 임계값 간의 관계를 분석하였다.

• Journal of information and communication convergence engineering
• /
• 제10권4호
• /
• pp.378-383
• /
• 2012

This paper presents the implementation of an automatic road sign recognizer for an intelligent transport system. In this system, lists of road signs are processed with actions such as line segmentation, single sign segmentation, and storing an artificial sign in the database. The process of taking the video stream and extracting the road sign and storing in the database is called the road sign recognition. This paper presents a study on recognizing traffic sign patterns using a segmentation technique for the efficiency and the speed of the system. The image is converted from one scale to another scale such as RGB to grayscale or grayscale to binary. The images are pre-processed with several image processing techniques, such as threshold techniques, Gaussian filters, Canny edge detection, and the contour technique.

• 대한원격탐사학회지
• /
• 제25권3호
• /
• pp.271-285
• /
• 2009

Multi-temporal satellite imagery can be changed into a transform image that emphasizes the changed area only through the application of various change detection techniques. From the transform image, an automated change detection model calculates the optimal threshold value for classifying the changed and unchanged areas. However, the model can cause undesirable results when the histogram of the transform image is unbalanced. This is because the model uses a single threshold value in which the sign is either positive or negative and its value is constant (e.g. -1, 1), regardless of the imbalance between changed pixels. This paper proposes an advanced method that can improve accuracy by applying separate threshold values according to the increased or decreased range of the changed pixels. It applies multiple threshold values based on the cumulative producer's and user's accuracies in the automated binary change detection model, and the analyst can automatically extract more accurate optimal threshold values. Multi-temporal IKONOS satellite imagery for the Daejeon area was used to test the proposed method. A total of 16 transformation results were applied to the two study sites, and optimal threshold values were determined using accuracy assessment curves. The experiment showed that the accuracy of most transform images is improved by applying multiple threshold values. The proposed method is expected to be used in various study fields, such as detection of illegal urban building, detection of the damaged area in a disaster, etc.

• 한국습지학회지
• /
• 제14권4호
• /
• pp.571-580
• /
• 2012

본 연구에서는 산지하천 유역인 설마천 유역에 대하여 GIS기법을 이용한 지형기후학적 순간단위도(GcIUH)를 유도하고, 돌발홍수 예측을 위한 기준우량을 산정하는 것을 목적으로 하고 있다. GIS기법을 적용하여 GcIUH를 유도하였으며, 유효우량을 산정하기 위한 NRCS-CN값을 산정하였다. 산정된 GcIUH를 이용하여 2011년 주요 호우사상에 대하여 분석하였다. 그 결과 전적비교의 경우 한계유출량을 초과하지 않는 것으로 분석되었으며, 사방교의 경우 모의된 첨두유출량이 약 $149.4m^3/s$로 한계유출량을 초과하는 것으로 분석되었다. 기준우량을 산정하기 위하여 50년 빈도의 설계홍수량에 해당하는 수심을 한계수심으로 설정하고, 지속기간을 고려하여 돌발홍수 기준우량을 산정하였다. 향후에는 다양한 홍수사상에 대하여 분석하고 이를 통해 한계유출량 및 기준우량의 적합성을 평가하고자 하며, 이를 바탕으로 산지하천 유역의 특성을 고려한 돌발홍수예측시스템 프로토타입을 개발하고자 한다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.2368-2372
• /
• 2005

We proposed a novel method for object recognition using the Smart tag system in the previous research. We identified the object easily, but could not assure the object pose, because the threshold problem was not solved. So we propose a new method to solve this threshold problem. This method uses a smart tag to decide the threshold by recording color information of the image when the object feature is extracted. This method records the original of the object color information at the smart tag first. And then it records the object image information, the circumstance image information and the sensors information continuously when the object feature is extracted through the experiments. Finally, it estimates the current threshold by recorded information. This method can be applied the threshold to each objects. And it can solve the difficult threshold decision problem easily. To approve the possibility of our method, we implemented our approach by using easy and simple techniques as possible.

• 한국통신학회논문지
• /
• 제18권2호
• /
• pp.279-287
• /
• 1993

본 논문은 다중등급의 통화유량에 대해 효율적인 처리를 위하여 동적 우선순위 스케쥴링이 가능한 2중이완성 한계치를 갖는 최소이완성한계 (Minimum Laxity Threshold:MLT)알고리즘과 2중 대기행열 한계치를 갖는 대기 행열간격한계(Queue Length Threshold QLT) 알고리즘을 제안하였다. 그리고 제안한 알고리즘의 성능을 컴퓨터 시뮬레이션을 통하여 분석하였다. 시뮬레이션 결과, 실시간서비스 중 지연민감도가 다른 2개 등급 이상의 통화유량 처리시2중 이완성 한계치를 갖는 MLT알고리즘을 적용함으로써 MLT알고리즘 자체보다 처리 효율성이 개선됨을 확인하고, 또2개 등급 이상의 비실시간 통화유량에 대해서는 2중 대기행열 한계치를 갖는 QLT알고리즘이 QLT보다 우수함을 알 수 있었다.