• Journal of Korea Multimedia Society
• /
• v.17 no.4
• /
• pp.466-477
• /
• 2014

Many image hiding schemes based on least significant bit (LSB) transformation have been proposed. One of the LSB-based image hiding schemes that employs diamond encoding was proposed in 2008. In this scheme, the binary secret data is converted into base n representation, and the converted secret data is concealed in the cover image. Here, we show that this scheme has two vulnerabilities: noticeable spots in the stego-image, i.e., a non-smooth embedding result, and inefficiency caused by rough re-adjustment of falling-off-boundary value and impractical base translation. Moreover, we propose a new scheme that is efficient and produces a smooth and high quality embedding result by restricting n to power of 2 and using a sophisticated re-adjustment procedure. Our experimental results show that our scheme yields high quality stego-images and is secure against RS detection attack.

• Proceedings of the KIPE Conference
• /
• 1998.07a
• /
• pp.95-98
• /
• 1998

Applying the magnetically levitated transportation system, which is noncontact bearing system, to solve the problems such as transformation of original form or flaw of iron plate caused by transportation of thin iron plate which required high quality as body of motor vehicle, materials of electronic devices etc.. Magnetic saturation phenomena caused by thickness of iron plate and gap size between magnets. In case of iron plate, the vibration mode will be considered since vibration occurs during transportation. In order to solve the problems caused by vibration, choose the levitation system method using numbers of magnet, magnetic saturation for thickness and length of iron plate with parameters in location and gap of magnet. In this paper, we will suggest the whole design technique of magnetically levitated transportation system, namely method of magnetic attraction and transportation system

• Journal of the Korean Institute of Landscape Architecture
• /
• v.27 no.2
• /
• pp.140-151
• /
• 1999

The purpose of this study is to trace historical changes and to show broad spectrums in landscape architectural drawing. Drawing has been both a locus of interpreting a site and a vehicle of imagining the new landscape. The designed landscape might be influenced by the way to draw in landscape design. Despite of its importance, landscape architectural drawing has rarely been discussed. Here, the drawing will be understood as theoretical issues and texts for criticism. Recently, the drawing has primarily been recognized in functional and instrumental ways. The stereotypes office drawings such as plan, section, perspective, axonometric are typical examples. Its symbolic and metaphoric dimensions have been seriously diminished. As a result, the poetic power in the designed landscape might be devastated. Composite drawing, notation are the alternative drawings to overcome the above mentioned dilemma along with the adaption of collage and photomontage. Finally, I would argue that landscape architectural drawing can be a creative tool to elicit the idea and to reveal the trace of memory. It could be also a poetic locus to postulating the vision. Designers should utilize both traditional drawing and experimental drawing in order to reconcile the instrumental representation with the symbolic representation.

• Journal of the Korean Institute of Rural Architecture
• /
• v.12 no.2
• /
• pp.1-12
• /
• 2010

The results of Change of Space Organization of Nagan Eupsung are as follows. There was no castle when Nagan folk village was built and it was merely small village arranged centering around road, but as it was emphasized as a point of strategic importance, castle wall was built and the government office and military facilities were established. In the late period of the Joseon Dynasty, as central power was weakened and its importance as a strategic point was declined, private houses outside the folk village were extended to the inside of castle. The whole structure of the village was not greatly changed through the modern society, but disappearance of village components and change of its basic structure like destruction of the castle were continued not to be restored to the former condition spontaneously. It was considered that it was caused by social demographic characteristics of the folk village which was deteriorated and environmental factors that it was changed into sightseeing place.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.41 no.3
• /
• pp.281-291
• /
• 1992

This paper deals with the digital autopilot implementation for a launch vehicle. We propose a hardware and software system for digital autopilot implemented by microprocessor. The hardware system designed in this paper consists of CPU and memory board with 80286 MPU and 80287 NPU and I/O interface with A/D and D/A converters. The software system developed is composed of power-on self-test program, initializing program, interrupt service program, and control program. The performance of the overall system controlled by the digital autopilot implemented in this paper is evaluated via real-time simulations, which show that the control performances are satisfactory.

• Communications for Statistical Applications and Methods
• /
• v.16 no.1
• /
• pp.21-29
• /
• 2009

Engle and Russell (1998) proposed the ACD(Autoregressive Conditional Duration) model to explain the relationship between the prices and the duration times of the stocks. In this paper, we first introduce the various types of the ACD models such as the linear ACD, log ACD and Box-Cox ACD models and we evaluate the performance of the models for analysing the transaction data of the stocks in Korea.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.94-97
• /
• 2008

In this paper, A Digital Voltage Mode Controller is designed for the Photovoltaic power converter applications. The designed Digital Voltage Mode Controller is derived analytically from the continuous time small signal model of the boost converter. Due to the small signal model based derivations of the control law, the designed control method can be applicable to K-factor Approach method and bilinear transformation. In order to show the usefulness of a designed controller, and the simulation results are verified.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2001.11a
• /
• pp.255-259
• /
• 2001

본 연구에서는 긍/부정 판단 과제 시 연령간 뇌파 반응의 차이를 밝히고자 한다. 실험 대상의 연령은 10명(20대 5명, 60대 5명)이었으며, 모두 오른손잡이였다. 실험과제는 의미과제와 일화과제로 구분되며 각각 12문항으로 구성된다. 의미기억과제 덧셈문제를, 일화기억 과제는 도형을 이용하였으며, 마우스 버튼을 눌러 긍/부정 판단 반응을 하도록 하였다. 뇌파는 PE1, PF2, F3, F4, O1, O2에서 단극유도법으로 측정되었으며, EOG를 측정하여 뇌파분석 시에 눈 깜박임으로 인하 noise를 제거하도록 하였다. 뇌파 분석은 원자료를 FFT(Fast Fourier Transformation)를 수행하여 각 대역의 상대적인 power를 구하는 방법으로 이루어졌다. 분석 결과, 반응 시간은 긍/부정판단간의 차이는 없었으나, 두 과제 모두에서 연령별로 유의미한 차이가 있었다. 긍/부정판단간의 따른 뇌파 반응은 명확한 차이가 나타나지 않았다. 연령에 따른 뇌파반응은 theta파, slow beta, fast beta에서 유의한 차이가 나타났다.

• Journal of Korean Society for Atmospheric Environment
• /
• v.13 no.4
• /
• pp.297-305
• /
• 1997

The experimental study by use of SPCP was fulfilled to remove toluene emitted from various industrial processes. First of all, discharge characteristic was experimented as the change of applied voltage and frequency. Then toluene removal characteristic was tested with the analysis of by-products. As a result, optimum electrical discharge condition was from 20.0 kHz to 25.0 kHz of frequency and from 3.5 kV to 4.0 kV of voltage range. The variation of applied voltage had a more important effect on the removal characteristic of toluene than the frequency variation. The toluene removal efficiency was proportioned to ozone concentration and retention time on discharge plate. It was dropped as increase of toluene concentration, but total treated volume of tolene per power consumption was high. The decomposed toluene was transformed to $CO, CO_2$ and particulates, and the rate of transformation to particulates was higher than CO and $CO_2$ at high toluene concentration. Particulates were increased from 0.017 $\mum$ to 0.3 $\mum$ range of size distribution.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.8
• /
• pp.1240-1245
• /
• 2015

The purpose of this paper is to investigate the autonomic nervous system activity in various ambient temperatures. To evaluate autonomic function, we use the frequency domain analysis of heart rate variability such as FFT(fast fourier transformation), AR(Auto-Regressive) model and Lomb-Scargle peridogram. HRV(heart rate variability) is calculated by using ECG recorded from 3 different temperature room which temperature is controlled in 18℃(low), 25℃(mid) and 38℃(high), respectively. Totally 22 subjects were participated in the experiment. In the results, the most significant autonomic changes caused by temperature load were found in the HF(high frequency) component of FFT and AR model. And the HF power is decreased by increasing temperature. Significance level was increased by increasing the difference of temperatures.