• 대한인간공학회지
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• 제36권2호
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• pp.145-156
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• 2017

Objective: This study aims to compare the usability of the adaptive touch design method with that of the height adjustable design method that are applied to the Korean QWERTY keyboard and Naratgul keyboard on smartphones, examine the results, and present practical implications. Background: Smartphone manufacturers have failed to satisfy every user with their uniform touch keyboard designs that do not consider the high use rates of keypad use. In reality, touch keyboard designing customized for every individual is impossible, but there need to be researches on was to improve usability by having touch areas changed automatically depending on user behaviors or having users adjust the keyboard height depending on their hand size. Method: As for the design methods, an object group was given smartphones with the adaptive touch design method and the other group those with the height adjustable design method. As they entered the same characters in the smartphones, typing error rates and text input speed were measured and the average values were compared. 35 individuals who would frequently use smartphones in daily life participated in the experiment. The group variable was the type of touch keyboards, and the test variables were typing error rates and text input speed, for which a T-test was implemented. Results: As for the QWERTY keyboard, the significant improvement effect was verified as the typing error rate of the adaptive touch design method was 4.21% but that of the height adjustable design method was 3.28% although there was no significant difference in terms of text input speed. As for the Naratgul keyboard, in contrast, the typing error rate of the adaptive touch design method was 2.5% while that of the height adjustable design method was 1.48%, which indicates a measure of improvement, but the effect was not significant. On the other hand, the text input speed per minute was improved as much as 22.2%, which is significant. Conclusion: First, the Korean touch keyboard usability of the adaptive touch design method and that of the height adjustable design method, when applied to Model A of Company L, showed significant difference from each other. Second, the height adjustable design method was applied to the QWERTY keyboard, the typing error rate was improved significantly. This indicates that as the keyboard height was raised, the number of buttons within the range of fingering decreased, decreasing the touch bias was reduced. Third, the height adjustable design method was applied to the Naratgul keyboard, the text input speed was improved. Application: When the QWERTY keyboard was applied to a smartphone as small as 5.5inch or less, it is highly probably that the height adjustable design method decreases the typing error rate. It may be considered to develop additional UX functions to make the keyboard font larger or give users the option to adjust button intervals in utilization of the SW advantages of the height adjustable design method.

• 한국정보처리학회논문지
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• 제4권6호
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• pp.1481-1494
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• 1997

실시간 시스템에서 시간적 제약의 불이행의 커다란 손실을 가져오며, 이를 위한 동적 스케쥴링은 유연성을 제공하는 대신 스케쥴링 오버헤드와 분석작업의 복잡성으로 인하여 스케쥴성을 예측하기 어려움이 있다. 반면, 정적 스케쥴링은 수행 중 오버헤드가 없으므로 정확한 시간을 예측할 수 있는 장점이 있다. 따라서 명령어 수준의 정적 스케쥴링과 시간 분석을 통하여 시스템의 시간적 정확도를 보장할 수 있다. 본 논문에서는 확정된 시간 분석을 위하여 befor와 after의 시간 제약을 고급 언어에 표현하고 이를 근거로 시간적 분석에 기반을 둔 컴파일러의 명령어 수준의 스케쥴링 알고리즘을 제안하였다. 이 스케쥴링의 특징은 명령어 수준의 스케쥴링을 위한 도메인이 지나치게 과대하므로 향상된 적합 유전자 알고리즘을 적용한 것이다.

• 한국멀티미디어학회논문지
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• 제9권11호
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• pp.1455-1464
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• 2006

본 논문에서는 컬러 이미지에 적합한 화질 향상 알고리듬을 제안 하였다. 제안된 알고리듬은 입력 이미지의 명도 향상을 위한 MIE기법과 채도 향상을 위한 MSE기법으로 구분된다. MIE기법은 휘도 신호 처리 시 발생하는 색 재현 문제 및 과도한 밝기 변화를 제어하기 위한 알고리듬이고, MSE기법은 색차 신호 처리 시 발생하는 De-Saturation 혹은 Over-Saturation의 발생을 제어하기 위한 알고리듬이다. 제안된 알고리듬은 인간의 시각선호색을 중심으로 연산하며, 전체 이미지에 균등하게 적용하는 것 보다 고품질의 이미지를 얻을 수 있다. 제안한 알고리듬은 고화질을 위한 모니터나 TV등의 디스플레이 장치에 적용 가능하다.

• 한국전산구조공학회논문집
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• 제30권4호
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• pp.283-288
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• 2017

스폿 용접 접합의 삼차원 모델링을 위하여 강한 불연속이 내장된 유한요소를 사용하였다. 스폿 용접의 기하학적 형상을 유한요소망 대신 요소에 내장된 불연속 면에서의 특수한 응집 법칙을 이용하여 표현하였다. 이를 통하여 기존의 적응적 유한요소망을 이용하는 접근법과 달리 스폿 용접의 국부적인 형상에 독립적인 유한요소망을 구성할 수 있다. 또한, 스폿 용접의 형상을 명시적으로 고려하여 모델링함으로써 기존의 점 구속조건을 이용하는 접근법과 달리 망 독립적인 해를 얻을 수 있다.

• 한국산업정보학회논문지
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• 제12권3호
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• pp.132-140
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• 2007

카메라 영상은 명도의 변화와 부정확한 초점으로 인해 스캐너 영상에 비하여 화질이 저하된다. 본 연구에서는 카메라 영상에서 자주 발생하는 화질 저하에 대한 적응력을 강화하여 카메라기반 문서 인식에 적합한 이진화 방법을 제안한다. 기존의 평가에서 우수하다고 보고된 이진화 방법을 기반으로 하되, 낮은 조도와 부정확한 초점으로 인해 명도 대비가 낮은 영상에 대한 적응력을 강화하였다. 또한 이진화 시 국소 윈도우를 이용하여 기존의 방법에서 뭉개지기 쉬운 문자의 세부 구조를 섬세하게 추출하도록 개선하였다. 실험에서는 기존에 우수하다고 평가된 이진화 방법들과 제안하는 방법을 문서 인식에 적용하여 다양한 카메라 문서 영상에 대한 성능을 비교하였는데, 그 결과 제안하는 방법이 카메라로 입력받은 문서 영상의 인식에 효과적임을 확인하였다.

• 한국산학기술학회논문지
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• 제7권6호
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• pp.1231-1236
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• 2006

영상의 화질을 개선하기 위한 많은 방법 중 비교적 간단하게 사용되는 방법 중 하나는 영상의 대비를 조절하는 것이다. 이러한 대비를 조절하는 방법 중 하나인 히스토그램 균등화는 영상 계조도 값의 분포를 균등 분포로 변환함으로써 화질을 개선한다. 그러나, 기존의 방법은 영상의 히스토그램 분포가 몇개의 계조도 값에 군집화되어 있다면 영상의 계조도가 과도하게 변하는 단점을 갖는다. 본 논문은 그레이스케일 영상에 대해 히스토그램의 형태를 고려해서 가우시안 함수에 기반한 히스토그램 매칭 방법을 제안한다. 제안된 방법은 영상이 과도하게 밝아지는 것을 제한하고 히스토그램의 분포가 몇 개의 계조도에 군집화되어 있는 영상에서의 에지 및 어두운 부분의 자세한 정보를 표현하는데 우수한 성능을 나타내었다.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4591-4596
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• 2023

Single-photon emission computed tomography SPECT image reconstruction methods have a significant influence on image quality, with filtered back projection (FBP) and ordered subset expectation maximization (OSEM) being the most commonly used methods. In this study, we proposed newly-designed adaptive non-blind deconvolution with a structural similarity (SSIM) index that can take advantage of the FBP and OSEM image reconstruction methods. After acquiring brain SPECT images, the proposed image was obtained using an algorithm that applied the SSIM metric, defined by predicting the distribution and amount of blurring. As a result of the contrast to noise ratio (CNR) and coefficient of variation evaluation (COV), the resulting image of the proposed algorithm showed a similar trend in spatial resolution to that of FBP, while obtaining values similar to those of OSEM. In addition, we confirmed that the CNR and COV values of the proposed algorithm improved by approximately 1.69 and 1.59 times, respectively, compared with those of the algorithm involving an inappropriate deblurring process. To summarize, we proposed a new type of algorithm that combines the advantages of SPECT image reconstruction techniques and is expected to be applicable in various fields.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.799-802
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• 2004

In this paper, the active backlight control technology with data processing algorithm was developed in order to improve image quality for IPS-mode LCD-TV applications. The image blinking problem caused by repeatedly abrupt change of the backlight luminance was solved by algorithms-Fba(Flexible Boundary algorithm) and Cfa(Cumulative Feedback algorithm)-and the optimized number and space of backlight dimming steps based on perception. In the IPS-mode 42" TFT-LCD panel, the dynamic contrast ratio can be more than twice the typical level by means of lower block luminance and higher white luminance. Additionally, Power consumption and LCD temperature was decreased.

• IEIE Transactions on Smart Processing and Computing
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• 제1권1호
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• pp.8-16
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• 2012

An image obtained from a low light environment results in a low-exposure problem caused by non-ideal camera settings, i.e. aperture size and shutter speed. Of particular note, the multiple color-filter aperture (MCA) system inherently suffers from low-exposure problems and performance degradation in its image classification and registration processes due to its finite size of the apertures. In this context, this paper presents a novel method for the color enhancement of low-exposure images and its application to color shift model-based MCA system for image refocusing. Although various histogram equalization (HE) approaches have been proposed, they tend to distort the color information of the processed image due to the range limits of the histogram. The proposed color enhancement algorithm enhances the global brightness by analyzing the basic cause of the low-exposure phenomenon, and then compensates for the contrast degradation artifacts by using an adaptive histogram specification. We also apply the proposed algorithm to the preprocessing step of the refocusing technique in the MCA system to enhance the color image. The experimental results confirm that the proposed method can enhance the contrast of any low-exposure color image acquired by a conventional camera, and is suitable for commercial low-cost, high-quality imaging devices, such as consumer-grade camcorders, real-time 3D reconstruction systems, digital, and computational cameras.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8351-8358
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• 2016

Electronic cleansing is an image post processing technique in which the tagged colonic content is subtracted from colon using CTC images. There are post processing artefacts, like: 1) soft tissue degradation; 2) incomplete cleansing; 3) misclassification of polyp due to pseudo enhanced voxels; and 4) pseudo soft tissue structures. The objective of the study was to subtract the tagged colonic content without losing the soft tissue structures. This paper proposes a novel adaptive method to solve the first three problems using a multi-step algorithm. It uses a new edge model-based method which involves colon segmentation, priori information of Hounsfield units (HU) of different colonic contents at specific tube voltages, subtracting the tagging materials, restoring the soft tissue structures based on selective HU, removing boundary between air-contrast, and applying a filter to clean minute particles due to improperly tagged endoluminal fluids which appear as noise. The main finding of the study was submerged soft tissue structures were absolutely preserved and the pseudo enhanced intensities were corrected without any artifact. The method was implemented with multithreading for parallel processing in a high performance computer. The technique was applied on a fecal tagged dataset (30 patients) where the tagging agent was not completely removed from colon. The results were then qualitatively validated by radiologists for any image processing artifacts.