• 반도체디스플레이기술학회지
• /
• 제23권2호
• /
• pp.23-27
• /
• 2024

Underwater images are typically degraded due to color distortion, light absorption, scattering, and noise from artificial light sources. Restoration of these images is an essential task in many underwater applications. In this paper, we propose a two-phase deep learning-based method, Underwater Deep Curve Estimation (UWDCE), designed to effectively enhance the quality of underwater images. The first phase involves a white balancing and color correction technique to compensate for color imbalances. The second phase introduces a novel deep learning model, UWDCE, to learn the mapping between the color-corrected image and its best-fitting curve parameter maps. The model operates iteratively, applying light-enhancement curves to achieve better contrast and maintain pixel values within a normalized range. The results demonstrate the effectiveness of our method, producing higher-quality images compared to state-of-the-art methods.

• 국제물리치료학회지
• /
• 제3권1호
• /
• pp.370-377
• /
• 2012

This study examines the effects of different environments on the application of hemiplegia patients circuit balance training. Group 1 performed circuit balance training without any auditory intervention Group 2 performed training in noiseless environments and Group 3 performed training in white noise environments. First, among lower extremity muscular strength evaluation items, maximum activity time(MAT) was not significantly different(p>.05). Maximum muscle strength(MMS) increased significantly in Group 3(p<.01), there was no significant difference in MMS among the groups. Average muscle strength(AMS) indexes also significantly increased in Group 3(p<.01), there was no significant difference in AMS among the groups. Second, among balancing ability evaluation items, Berg's balance scale(BBS) scores significantly increased in all groups(p<.05), BBS scores were significantly difference among the groups. Based on the results, Group 1, 2 and Group 1, 3 showed significant increases (p<.05). Functional reach test(FRT) values significantly increased in Group 2, 3(p<.05), and there was no significant difference in FRT values among the groups. Timed up and go(TUG) test values significantly decreased in Group 2, 3(p<.05), and there was no significant difference in TUG test values among the groups. Third, among walking speed evaluation items, the time required to walk 10m significantly decreased in all groups(p<.05), and there was no significant difference in the values among the groups. Average walking speeds showed significant increases in Group 1, 3(p<.05), and there was no significant difference in the values among the groups. Based on the results of this study, noise environments should be improved by either considering auditory interventions and noiseless environments, or by ensuring that white noise environments facilitate the enhancement of balancing ability.

• 한국운동역학회지
• /
• 제30권4호
• /
• pp.301-309
• /
• 2020

Objective: This study aimed to investigate the effect of white noise on dynamic balance in patients with stroke during walking. Method: Nineteen patients with chronic stroke (age: 61.2±9.8 years, height: 164.4±7.4 cm, weight: 61.1±9.4 kg, paretic side (R/L): 11/8, duration: 11.6±4.9 years) were included as study participants. Auditory stimulus used white noise, and all participants listened for 40 minutes mixing six types of natural sounds with random sounds. The dynamic balancing ability was evaluated while all participants walked before and after listening to white noise. The variables were the center of pressure (CoP), the center of mass (CoM), CoP-CoM inclined angle. Results: There is a significant increase in the antero-posterior (A-P) CoP range, A-P inclination angle, and gait speed on the paretic and non-paretic sides following white noise intervention (p<.05). Conclusion: Our findings confirmed the positive effect of using white noise as auditory stimulus through a more objective and quantitative assessment using CoP-CoM inclination angle as an evaluation indicator for assessing dynamic balance in patients with chronic stroke. The A-P and M-L inclination angle can be employed as a useful indicator for evaluating other exercise programs and intervention methods for functional enhancement of patients with chronic stroke in terms of their effects on dynamic balance and effectiveness.

• Journal of the Optical Society of Korea
• /
• 제17권6호
• /
• pp.506-512
• /
• 2013

Recently, the color separation issue of wide-spreading white LEDs has attracted attention due to their wide applicability as light sources in direct-lit LCD backlights. These wide-spreading LED packages usually consist of LED chips, a color-conversion phosphor layer, and a light-shaping lens. The technical aspect of this color issue was related to a method for balancing the yellow spectral component emitting from phosphors with respect to the blue one from the LED chip as a function of viewing angle. In this study, we suggested an approach for carrying out quantitative analysis for the color separation problem occurring in wide-spreading LED packages by optical simulation. In addition, the effect of an internal scattering layer on the color uniformity was investigated, which may be considered as a potential solution for this problem.

• 천문학회보
• /
• 제44권2호
• /
• pp.72.1-72.1
• /
• 2019

Symbiotic stars are wide binary systems of a white dwarf and a mass losing giant, exhibiting various activities mainly attributed to accretion of a fraction of slow stellar wind emanating from the giant. We perform 3 dimensional hydrodynamical simulations using the FLASH code to investigate the formation and physical structures of an accretion disk in symbiotic stars with binary separation in the range of 2-4 au. Radiative cooling is introduced in the flow in order to avoid acute pressure increase in the vicinity of the accretor that may prevent stable disk formation. By setting the same density condition in front of the bow shock generated in two different velocity fields, the role of ram pressure balancing between the disk and the wind is examined. We find that three main streams (direct stream from the giant, stream following the accretion wake, and stream passing through the bow shock front) all feed the disk, and their individual contributions on the mass accretion onto the white dwarf are explored.

• 한국정보통신학회논문지
• /
• 제12권8호
• /
• pp.1349-1355
• /
• 2008

최근에 ZigBee, Bluetooth, RFID(Radio Frequency Identification)와 같은 근거 리 무선통신 시스템에 대한 연구가 활발히 진행되고 있으며, 이와 같은 시스템들은 대부분 소출력무선기기들이다. 미래에는 개인을 중심으로 하는 WPAN(Wireless Personal Area Network)을 위해서 더 많은 소출력 무선기기들이 출현할 것이며, 간섭저감기술은 소출력무선기기들이 한정된 주파수 자원을 효율적으로 이용하기 위한 필수 기술이 될 것으로 예상된다. 본 논문에서는 두 가지의 주파수를 공유 방법을 고려하였다. 첫 번째는 이미 특정 시스템에 할당된 주파수를 공유하는 경우이고, 두 번째는 새로운 주파수대역을 할당하는 경우이며, 이 두 가지 경우에 대한 효율적인 주파수 공유 방법을 연구하였다. 첫 번째 방법으로 주파수출 공유하는 경우의 한 가지 예로서 ZigBee, RPID, DCP(Digital Cordless Phone) 및 Bluetooth가 특정 주파수대역을 공유하는 경우 주파수 공유 조건을 검토하였다. 그리고 두 번째 공유 방법에서는 서로 다른 간섭저감기술을 사용하는 통신시스템에 대해서 공평한 신호 방사조건을 유지하기 위한 balancing factor의 개념을 제안하였으며, FH(Frequency Hopping) 시스템을 기준으로 하는 경우 LBT(Listen Before Talk)는 0.9, DS (Direct Spreading)은 0.8의 balancing factor를 이 용하면, 이들 간섭저감기술들 사이의 방사조건을 비슷하게 유지 할 수 있기 때문에 전체적으로 더 많은 시스템이 주파수를 공유할 수 있음을 보였다.

• 한국정보통신학회논문지
• /
• 제14권2호
• /
• pp.375-382
• /
• 2010

본 논문은 피사체의 고유의 색을 나타내기 위한 자동 백색 보정 기능에서 단색 영상에 대한 색상 왜곡현상을 보정하는 단색 영상 검출기의 구조개선 및 성능 향상을 수행한 구조를 제안한다. 제안한 구조는 뛰어난 효율성으로 인해 모바일 폰 카메라에 널리 사용되는 Grayworld 알고리듬을 통한 백색 보정 기능에 적용되는 단색 영상 검출기로써, 입력 영상의 색 분포 특성을 파악하여 단색 영상의 입력 시 해당 색상을 제외한 나머지 영역으로 자동 백색 보정기능을 수행하도록 하는 역할을 수행한다. 제안한 구조는 기존 구조에 비해 다양한 영상의 입력에 대응 가능하며, 영상의 크기 및 촬영 환경에 따라 임계값의 변경이 가능하도록 설계하였다. 또한 하드웨어 구조의 간소화를 통해 기존 대비 약 80%의 하드웨어 크기가 감소되었다.

• 한국농림기상학회지
• /
• 제1권2호
• /
• pp.110-118
• /
• 1999

This experiment was conducted to characterize the vertical transport trend of dissolved elements through throughfall, stemflow, effluent from Ao layer, and leachate out of soil profile on Pinus koraiensis stand in Experimental Forest of Kyunghee University, located in Kwangju, Kyunggi province for 12 months from July, 1998 to Jun, 1999. In addition, we investigated the content of dissolved elements and the factors influencing the water chemistry concentrations separately collected from the field. Water movement in the process of throughfall and stemflow from precipitation, and rainfall leached from Ao layer into soil water was governed by concentration of through fall, precipitation, rainfall intensity, seasonal variation, and other factors. Also, smaller changes of pH in soil water than that of dissolved elements in soil water could contribute buffer capacity, as well as balancing the concentration between cations and anions.

• 정보처리학회논문지D
• /
• 제8D권6호
• /
• pp.681-690
• /
• 2001

본 논문에서는 컴포넌트에 기반한 소프트웨어 개발(CBSD) 환경의 전반적인 활성화 개념을 제시한다. 컴포넌트 기술에 대한 연구가 컴포넌트를 시스템 구축에 효율적으로 적용하려는 쪽으로 집중되어, 컴포넌트 시장의 활성화 방안이나 컴포넌트 자체의 개발 방식 등에 대해서는 지속적인 연구가 필요한 상태이다. 우선 CBSD 활성화로의 장애요소를 진단하고 이를 해결하기 위한 방안으로 중개개념 고려의 필요성을 강조한다. 그러나 단순한 사전적 의미로의 중개개념으로는 CBSD 활성화를 도모할 수 없으므로 중개개념에 부가적인 서비스를 추가한 “부가가치 중개 개념”이 요구된다. 부가가치 중개 개념에는 크게 1) 도메인 아키텍쳐 지향의 컴포넌트 생산 촉진, 2) 지능형 컴포넌트 검색 서비스, 3) 화이트 박스 서비스의 세 가지 기능을 수행한다. 도메인 아키텍쳐 지향의 컴포넌트 생산 촉진은, 균형 잡힌 컴포넌트 생산과 아키텍쳐 중심의 대단위 재사용을 꾀할 수 있다. 지능형 컴포넌트 검색 서비스는, 컴포넌트 생산자와 소비자 간의 1：1 거래의 한계를 해결해주고 마지막으로 화이트 박스 서비스는 컴포넌트 도입의 가장 큰 걸림돌인 유지보수 문제를 보장해준다. 특히 이 개념은 국내 컴포넌트 개발의 특수 상황에 적용하여 큰 효과를 얻을 수 있을 것으로 기대된다.

• ETRI Journal
• /
• 제32권5호
• /
• pp.750-760
• /
• 2010

We propose a homology between thermodynamic systems and images for the treatment of time-varying imagery. A physical system colder than its surroundings absorbs heat from the surroundings. Furthermore, the absorbed heat increases the entropy of the system, which is closely related to its disorder as given by the definition of Clausius and Boltzmann. Because pixels of an image are viewed as a state of lattice-like molecules in a thermodynamic system, the task of reckoning the entropy variations of pixels is similar to estimating their degrees of disorder. We apply this homology to the uncalibrated stereo matching problem. The absence of calibrations alleviates user efforts to install stereo cameras and enables users to freely modify the composition of the cameras. The proposed method is also robust to differences in brightness, white balancing, and even focusing between stereo image pairs. These peculiarities enable users to estimate the depths of interesting objects in practical applications without much effort in order to set and maintain a stereo vision setup. Users can consequently utilize two webcams as a stereo camera.