• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제17권1호
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• pp.89-99
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• 2018

The number of traffic accidents in Korea has been increasing since 2014. In most school zones, safety signs are installed to prevent children's traffic accidents. However, it has been known that the effects of those signs are not significant. A variable message sign(VMS), one of the components of Intelligent Transport System(ITS), has emerged as an alternative method. Therefore, this study examines relative effects of two different VMS messages(Timely vs. Continuous) on vehicle speed. Experiments were conducted in two school zones. 6,676 vehicles were measured for speed limit compliance. A counterbalanced multiple baseline design was adopted. The results showed that both types of message are effective in reducing the speed of vehicle. Specifically, A timely message was more effective in slowing down vehicle speed and improving speed limit compliance than a continuous message. The present study suggested that a VMS with human factors can be effective.

• Journal of the Korean Institute of Intelligent Systems
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• 제15권2호
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• pp.149-162
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• 2005

This paper suggest a way to detect a specific wanted figure in public places such as subway stations and banks by comparing color face images extracted from the real time CCTV with the face images of designated specific figures. Assuming that the characteristic of the surveillance camera allows the face information in screens to change arbitrarily and to contain information on numerous faces, the accurate detection of the face area was focused. To solve this problem, the normalization work using subsampling with $20{\times}20$ pixels on arbitrary face images, which is based on the Perceptron Neural Network model suggested by R. Rosenblatt, created the effect of recogning the whole face. The optimal linear filter and the histogram shaper technique were employed to minimize the outside interference such as lightings and light. The addition operation of the egg-shaped masks was added to the pre-treatment process to minimize unnecessary work. The images finished with the pre-treatment process were divided into three reception fields and the information on the specific location of eyes, nose, and mouths was determined through the neural network. Furthermore, the precision of results was improved by constructing the three single-set network system with different initial values in a row.

• Journal of the Korean Institute of Landscape Architecture
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• 제37권1호
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• pp.120-130
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• 2009

This study focuses on the methodology of an ecological interpretation of Korean traditional landscapes through both life-oriented philosophy and traditional Korean philosophy which are similar to ecology. Also, useful tools for discovering an ecological technique of formation based on the ecological thoughts in ancestors' life are shown. Ecological key words as interpretative tools on the traditional landscape replaced ecological concepts in Korean culture and landscape. There are 'Bonsung(本性; the original nature)', 'Chungjeol(中絶; moderation)', 'Hyoyul(效率; efficiency)', 'Sangsaeng(相生; symbiosis)', 'Jasaeng(自生; self-generation)', 'Chunghwa(中和; neutralization)', 'Bangtong(旁通; communication)', and 'Byuntong(變通; variableness)'. For the case study, the concepts of 'spatial structure', 'constructive elements in the traditional gardens', and 'structural elements in the dwelling houses' were extracted from $\ulcorner$Imwonkyeongjeji$\lrcorner$ as an interpretative subject. As a result, Jeongon house, Jongtaek of Choi's family(the first incoming resident) showed us an ecological technique of formation by interpretation on the composing elements. Namely, they are natural dwelling houses in harmony with natural conditions and delicate relational styles. Five kinds of ecological characteristics were exposed. They are: 1. land use method following natural features('本性' '相生' '中和'), 2. physical and spatial elements in a body with nature('中絶' '相生' '中和'), 3. sustainable circulation system by recycling limited resources('效率' '自生' '旁通'), 4. use of natural materials based on the regional climate ('中絶' '效率' '自生') and 5. plane and structural decision by microclimate('效率' '自生' '變通'). Consequently, the dwelling houses and their traditional gardens aimed at the consuming space of the efficient resources by utilizing and circulating natural energy more than different types of the traditional spaces.

• Korean Journal of Environmental Biology
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• 제34권4호
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• pp.240-245
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• 2016

This study was conducted to predict the changes of potential distribution for invasive alien plant, Amaranthus viridis in Korea. The habitats of A. viridis were roadside, bare ground, farm area, and pasture, where the interference by human was severe. We used maximum entropy modeling (MaxEnt) for analyzing the environmental influences on A. viridis distribution and projecting on two different representative concentration pathways (RCP) scenarios, RCP 4.5 and RCP 8.5. The results of our study indicated annual mean temperature, elevation and precipitation of coldest month had higher contribution for A. viridis potential distribution. Projected potential distribution of A. viridis will be increased by 110% on RCP 4.5, 470% on RCP 8.5.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제18권12호
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• pp.88-92
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• 2017

Owing to the depletion of fossil energy, wind power is attracting attention as a promising environmentally friendly alternative energy source, because it is abundant, renewable, and non-polluting. Wind turbines are divided into horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs) according to the direction of the rotating shaft. VAWTs have a low power generation efficiency, but are not affected by the wind direction and, thus, no yaw system is required and their structure is simple. Small VAWTs are attracting much attention because they can generate power even at low wind speeds. In this study, the output voltages and output currents of small VAWTs with gyromill type, hinge type and double door type blades capable of generating power even at low wind speeds were analyzed at variable wind speeds in the range of 1~11 m/s. At the maximum wind speed of 11m/s, the application of the double door type blades achieved 67% and 9% higher wind turbine output voltages than that of the gyromill type and hinge type blades, respectively. As regards the wind turbine output currents, the application of the double door type blades gave rise to 93% and 5% higher results than that of the gyromill type and hinge type blades, respectively. Through this study, the excellent output characteristics and commercialization potential of the double door type blades, which can generate power both at low and high wind speeds, were confirmed.

• Journal of Broadcast Engineering
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• 제18권6호
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• pp.835-849
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• 2013

Joint Collaborative Team on Video Coding (JCT-VC), which have founded ISO/IEC MPEG and ITU-T VCEG, has standardized High Efficiency Video Coding (HEVC). Standardization of HEVC has started with purpose of twice or more coding performance compared to H.264/AVC. However, flexible and hierarchical coding block and recursive coding structure are problems to overcome of HEVC standard. Many fast encoding algorithms for reducing computational complexity of HEVC encoder have been proposed. However, it is hard to implement a real-time HEVC encoder only with those fast encoding algorithms. In this paper, for implementation of software-based real-time HEVC encoder, data-level parallelism using SIMD instructions and CPU/GPU multi-threading methods are proposed. And we also proposed appropriate operations and functional modules to apply the proposed methods on HM 10.0 software. Evaluation of the proposed methods implemented on HM 10.0 software showed 20-30fps for $832{\times}480$ sequences and 5-10fps for $1920{\times}1080$ sequences, respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제19권5호
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• pp.97-105
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• 2020

Recently, for a smart city, there is a demand for a technology for acquiring traffic information using an intelligent road infrastructure and managing it. In the meantime, various technologies such as loop detectors, ultrasonic detectors, and image detectors have been used to analyze road traffic information but these have difficulty in collecting various informations, such as traffic density and length of a queue required for building a traffic information DB for moving vehicles. Therefore, in this paper, assuming a smart city built on the basis of a camera infrastructure such as intelligent CCTV on the road, a solution for calculating the traffic DB of moving vehicles using Vision Tracking of road CCTV cameras is presented. Simulation and verification of basic performance were conducted and solution can be usefully utilized in related fields as a new intelligent traffic DB calculation solution that reflects the environment of road-mounted CCTV cameras and moving vehicles in a variable smart city road environment. It is expected to be there.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제15권3호
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• pp.99-105
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• 2015

This paper deals with the mMMA (modified MMA) which possible to improving the convergence speed that employing the serial connecting form of two stage digital filter instead of signal filter of MMA adaptive equalizer without applying the variable step size for compensates the intersymbol interference by channel distortion in the nonconstant modulus signal. The adaptive equalizer can be implemented by signal digital filter using the finite order tap delay line. In this paper, the equalizer is implemented by the two stage serial form and the filter coefficient are updated by the error signal using the same algorithm of MMA in each stage. The fast convergence speed is determined in the first stage, and the residual isi left at the output of first stage output is minimized in the second stage filter. The same digital filter length was considered in single stage and two stage system and the performance of these systems were compared. The performance index includes the output signal constellation, the residual isi and maximum distortion, MSE that is measure of the convergence characteristics, the SER. As a result of computer simulation, mMMA that has a FIR structure of two stage, has more good performance in every performance index except the constellation diagram due to equalization noise and improves the convergence speed about 1.5~1.8 time than the present MMA that has a FIR structure of single stage.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제24권4호
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• pp.739-751
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• 2014

We are using our smartphone for our business as well as ours lives. Thus, user's privacy data and a company secret are stored at smartphone. By the way, the saved data on smartphone database can be exposed to a malicous attacker when a malicous app is installed in the smartphone or a user lose his/her smartphone because all data are stored as form of plaintext in the database. To prevent this disclosure of personal information, we need a database encryption method. However, if a database is encrypted, it causes of declining the performance. For example, when we search specific data in condition with encrypted database, we should decrypt all data stored in the database or search sequentially the data we want with accompanying overhead[1]. In this paper, we propose an efficient and searchable encryption method using variable length bloom filter under limited resource circumstances(e.g., a smartphone). We compare with existing searchable symmetric encryption. Also, we implemented the proposed method in android smartphone and evaluated the performance the proposed method. As a result through the implementation, We can confirm that our method has over a 50% improvement in the search speed compared to the simple search method about encrypted database and has over a 70% space saving compared to the method of fixed length bloom filter with the same false positive rate.

• The KIPS Transactions:PartB
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• 제16B권2호
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• pp.123-130
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• 2009

Motion estimation (ME) plays an important role in digital video compression. But it limits the performance of image quality and encoding speed and is computational demanding part of the encoder. To reduce computational time and maintain the image quality, integer pel and fractional pel ME methods are proposed in this paper. The proposed method for integer pel ME uses a hierarchical search strategy. This strategy method consists of symmetrical cross-X pattern, multi square grid pattern, diamond patterns. These search patterns places search points symmetrically and evenly that can cover the overall search area not to fall into the local minimum and to reduce the computational time. The proposed method for fractional pel uses full search pattern, center biased fractional pel search pattern and the proposed search pattern. According to block sizes, the proposed method for fractional pel decides the search pattern adaptively. Experiment results show that the speedup improvement of the proposed method over Unsymmetrical cross Multi Hexagon grid Search (UMHexagonS) and Full Search (FS) can be up to around $1.2{\sim}5.2$ times faster. Compared to image quality of FS, the proposed method shows an average PSNR drop of 0.01 dB while showing an average PSNR gain of 0.02 dB in comparison to that of UMHexagonS.