• 한국산업융합학회 논문집
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• 제23권6_2호
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• pp.1025-1032
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• 2020

In this paper, we propose a method to classify road weather conditions into rain, fog, and sun using a SVM (Support Vector Machine) classifier after extracting weather features from images acquired in real time using an optical sensor installed on a roadside post. A multi-dimensional weather feature vector consisting of factors such as image sharpeness, image entropy, Michelson contrast, MSCN (Mean Subtraction and Contrast Normalization), dark channel prior, image colorfulness, and local binary pattern as global features of weather-related images was extracted from road images, and then a road weather classifier was created by performing machine learning on 700 sun images, 2,000 rain images, and 1,000 fog images. Finally, the classification performance was tested for 140 sun images, 510 rain images, and 240 fog images. Overall classification performance is assessed to be applicable in real road services and can be enhanced further with optimization along with year-round data collection and training.

• Journal of Cardiovascular Imaging
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• 제30권4호
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• pp.231-262
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• 2022

There is a wide spectrum of congenital anomalies or variations of the aortic arch, ranging from non-symptomatic variations that are mostly detected incidentally to clinically symptomatic variations that cause severe respiratory distress or esophageal compression. Some of these may be accompanied by other congenital heart diseases or chromosomal anomalies. The widespread use of multidetector computed tomography (CT) in clinical practice has resulted in incidental detection of several variations of the aortic arch in adults. Thus, radiologists and clinicians should be aware of the classification of aortic arch anomalies and carefully look for imaging features associated with a high risk of clinical symptoms. Understanding the embryological development of the aortic arch aids in the classification of various subtypes of aortic arch anomalies and variants. For accurate diagnosis and precise evaluation of aortic arch anomalies, cross-sectional imaging modalities, such as multidetector CT or magnetic resonance imaging, play an important role by providing three-dimensional reconstructed images. In this review, we describe the embryological development of the thoracic aorta and discuss variations and anomalies of the aortic arch along with their clinical implications.

• 대한전자공학회논문지SP
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• 제43권2호
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• pp.1-11
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• 2006

본 논문에서는 샷(shot) 기반 비디오 색인 구조에서 비-파라미터(non-parametric) 기반의 움직임 분류를 통한 비디오 영상 검색 기법을 제안한다. 본 논문에서 제안하는 비디오 검색 시스템은 장면 전환 기법을 통해 얻은 샷 단위의 짧은 비디오로부터 대표 프레임과 움직임 정보를 취득한 후, 이를 통해 시각적 특징과 움직임 특징을 추출하여 유사도를 비교함으로써 시-공간적 특징을 이용한 실시간 검색이 가능하도록 구현되었다. 비-파라미터 기반의 움직임 특징의 추출은 MPEG 압축 스트림으로부터 정규화된 움직임 벡터계(界)를 추출한 후, 각각의 정규화된 움직임 벡터를 여러 개의 각도 빈(bin)으로 양자화하고 이의 평균과 분산, 방향 등을 고려함으로써 효과적으로 이루어진다. 대표 프레임에서의 시각 특징 검출을 위해서는 에지 기반의 공간 기술자를 이용하였다. 실험 결과는 영상 색인 및 검색에 있어서 제안된 시스템이 매우 효과적임을 잘 나타내고 있다. 데이터베이스 내 영상의 색인을 위해서는 R*-tree 구조를 이용한다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.215-218
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• 2007

이 논문은 고해상도 Quickbird 영상을 이용하여 세부레벨계획을 위한 토지피복분류를 수행하였으며 고해상도 영상을 이용한 토지피복분류를 위하여 객체기반분류와 ISODATA 기법을 적용하였다. 객체기반분류는 eCognition 소프트웨어를 사용하였으며 ISODATA 기법의 토지피복분류 결과와 비교분석을 수행하였다. 연구 대상지역은 인도의 Sukkalampatti이라 하는 작은 유역을 대상으로 연구를 진행하였다. 고해상도 영상의 사용으로 토지피복분류에 있어서 공간 해상도에 따른 토지피복의 세부레벨분류 정확도를 향상 시킬 수 있는 이점을 확인 할 수 있으며 또한, 객체기반분류와 ISODATA 기법의 분류 결과는 eCognition을 사용한 객체기반 토지피복분류결과가 ISODATA의 픽셀기반의 분류방법보다 높은 정확도를 보였다.

• Agribusiness and Information Management
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• 제6권2호
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• pp.1-12
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• 2014

HMR is a home-style food product designed for convenience and cooked outside the home leaving out cumbersome cooking process and consumed at home. The present paper aims to find out factors that influence the consumption of HMR by analyzing data on food consumption during the 3 years between December 2010 and November 2013. Following the classification of Costa et al. (2001), this study categorized HMR products as 3 types as follows: C1 (ready to eat), C2 (ready to heat) and C3 (ready to cook), and examined factors affecting purchase rate and per capita purchase price for each type of HMR product. The results of our analysis show that only the purchase rate of C3 products was influenced by whether the purchaser was housewife with job or not. For those who do not live together with parents, per capita purchase price for HMR was high; and the more they ate out, the higher the purchase rate of HMR was.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2089-2098
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• 2017

Microgrid is a convenient, reliable, and eco-friendly approach for the integration of Distributed Generation (DG) sources into the utility power systems. To date, AC microgrids have been the most common architecture, but DC microgrids are gaining an increasing interest owing to the provision of numerous benefits in comparison with AC ones. These benefits encompass higher reliability, power quality and transmission capacity, non-complex control as well as direct connection to some DG sources, loads and Energy Storage Systems (ESSs). In this paper, main challenges and available approaches for the protection of AC and DC microgrids are discussed. After description, analysis and classification of the existing schemes, some research directions including coordination between AC and DC protective devices as well as development of combined control and protection schemes for the realization of future hybrid AC/DC microgrids are pointed out.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.752-759
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• 2006

Conglomerates and core-stones are the typical composite geomaterials that are composed of a weak matrix and a strong pebble part. In general, we couldn't analyze the composite geomaterials by using emperical rock classification methods. In the study, a series of analyses of elastic behavior of composite geomaterials are carried out by using homogenization theory. 45-case models are made with considering 3 kind of factors such as gravel content, size and strength of matrix. Those are applicable to various composite geomaterials of conglomerates and core-stones. The size of analysis model is large enough to exceed REV.

• ETRI Journal
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• 제38권2호
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• pp.366-375
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• 2016

This paper describes an algorithm to suppress composite noise in a two-microphone speech enhancement system for robust hands-free speech communication. The proposed algorithm has four stages. The first stage estimates the power spectral density of the residual stationary noise, which is based on the detection of nonstationary signal-dominant time-frequency bins (TFBs) at the generalized sidelobe canceller output. Second, speech-dominant TFBs are identified among the previously detected nonstationary signal-dominant TFBs, and power spectral densities of speech and residual nonstationary noise are estimated. In the final stage, the bin-wise output signal-to-noise ratio is obtained with these power estimates and a Wiener post-filter is constructed to attenuate the residual noise. Compared to the conventional beamforming and post-filter algorithms, the proposed speech enhancement algorithm shows significant performance improvement in terms of perceptual evaluation of speech quality.

• Journal of Multimedia Information System
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• 제4권2호
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• pp.79-82
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• 2017

Smoke and fire have different shapes and colours. This article suggests a fully connected system which is used two features using Adaboost algorithm for constructing a strong classifier as linear combination. We calculate the local histogram feature by gradient and bin, local binary pattern value, and projection vectors for each cell. According to the histogram magnitude, this paper applied adapted weighting value to improve the recognition rate. To preserve the local region and shape feature which has edge intensity, this paper processed the normalization sequence. For the extracted features, this paper Adaboost algorithm which makes strong classification to classify the objects. Our smoke detection system based on the proposed approach leads to higher detection accuracy than other system.

• 농촌계획
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• 제8권1호
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• pp.77-84
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• 2002

This study intends to classify and analyze the problem of rural villages on the basis of existing ecological and cultural resources. Based on the results of this study, rural villages in Korea can be divided into 4 types - (1) the village abundant in both ecological and cultural resources, (2) the village abundant in only ecological resources, (3) the village abundant in only cultural resources and (4) the village insufficient in two resources. And further, this study found that most ecological resources in rural villages are deteriorated or deteriorating. Even worse, the cultural resources are diminished or diminishing. It is suggested that the ecological and cultural resources need to be taken into account in the process of rural village planning.