• Proceedings of the KIEE Conference
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1730-1733
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• 2004

Device miniaturization and high integrated circuit design is of major interest for the development of electronic devices. Various studies have been conducted to develop new material and processing technique[1]. Negative Differential Resistance(NDR) is the defining behavior in several electronic components, including the Esaki diode and most notably, resonant tunneling diodes(RTD)[2]. We made a comparison of electrical properties between 4,4-Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene and 4-[2,5-dimethoxy-4-(p henylethynyl)phenyl]ethynylphenylethanethioate, which have been well known as a conducting molecule having possible application to molecular level NDR devices. As a result, we measured current-voltage curves using Scanning Tunneling microscopy(STM), I-V curves also showed several current peaks between negative and positive bias region.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2004년도 학술대회지
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• pp.653-657
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• 2004

The average bit error rate (HER) performance of a Gray coded arbitrary rectangular quadrature amplitude modulation (AR-QAM) signal with maximal ratio combining (MRC) diversity in an arbitrarily correlated Nakagami-m fading channel is derived and analyzed. The derived two types of general solutions are a simple closed-form and an integral form, depending on the types of the values (integer and non-integer) of the fading parameter. Using the derived equations in this paper, we analyzed the HER performances numerically based on the practical base station antenna configuration. The results show that MRC reception is a very effective scheme so far even though the combined signals are not independent each other because of the correlation values. The antenna height and separation of the MRC system relate to the correlation coefficient value between antennas, and go a long way with the diversity advantage. In particular, it is needed to be determined the antenna height that is carefully do for the diversity advantage because the correlation coefficient and the antenna height gain are contrary to each other from the aspect of the system performance. The expressions presented here can offer a convenient way to evaluate the exact HER performance of an arbitrary rectangular QAM signal with MRC diversity reception for various cases of practical interest on a correlated Nakagami fading channel.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2004년도 학술대회지
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• pp.658-662
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• 2004

This paper proposes an orthogonal reception structure for OS/SS communication with time-shifted m-sequences, and compares the performances of the proposed and conventional receiver. This structure provides two important characteristics to reference user signal with not only increment of auto-correlation value but also cancel of the cross-correlation value out to zero between the reference user and other user signals. In addition, the structure can be easily implemented with the conventional receiver adding an additional integrator path in parallel and an adder that sums the conventional path output and the new path output signal. Hence, the proposed structure can be applied for channel impulse response measurement, and efficiently used for multi-user interference signal cancellation and channel capacity increment by flexible structural inter-working operation, connection or disconnection, of the new path to conventional receiver structure.

• Journal of Fisheries and Marine Sciences Education
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• 제13권1호
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• pp.19-36
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• 2001

The Government revised the sixth education curriculum plan because of rapid growth of information and communication technology, variance of computer applicable fields and curriculum plan related intelligence information. In according to this principle, the seventh curriculum plan remodeled not only knowledge cultivation as cultured person but also new curriculum correspond to special character of industrial high schools. The revised main contents are organized practicable subjects considering actual educational environments, deleted duplicated subjects and also added practicable another contents of multimedia and telecommunication fields. In this paper, we study curriculum for integrated computer education of industrial high schools according to the seventh education plan. For this research, it is searched opening classes and completion models of special subjects related computer fields of industrial high schools in Busan, we propose completion model for each school year and new curriculum of industrial high schools. We also recommend another approach methods for training and election of teachers. Therefore, this research can apply to the basis research data for the future curriculum model related computer science of industrial high schools.

• Journal of Korea Multimedia Society
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• 제18권11호
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• pp.1332-1341
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• 2015

This paper proposes a novel reversible secret sharing scheme using AES algorithm in encrypted images. In the proposed scheme, a role of the dealer is divided into an image provider and a data hider. The image provider encrypts the cover image with a shared secret key and sends it to the dealer. The dealer embeds the secret data into the encrypted image and transmits encrypted shadow images to the corresponding participants. We utilize Galois polynomial arithmetic operation over 2⁸ and the coefficient of the higher-order term is fixed to one in order to prevent the overflow. In experimental results, we demonstrate that the PSNR is sustained close to 44dB and the embedding capacity is 524,288 bits.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2002년도 추계학술발표논문집 (하)
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• pp.1983-1986
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• 2002

분산 인터넷 환경에서 웹 애플리케이션의 상호운영성, 유연성, 확장성, 유지보수성 재사용성을 높이기 위해서 프레임웍 및 패턴을 시스템 개발에 적용하는 연구가 진행되고 있다. 프레임웍 및 패턴을 사용하여 시스템을 개발하기 위해서는 여러 가지 설비(facility)를 요구하며 개발자는 시스템에 대해 보다 많은 부분을 고려해야 한다. 본 논문에서는 특정 도메인에서 MVC Model 2 프레임웍을 기반으로 하는 시스템에 대해 공통으로 사용 가능한 코드를 재사용할 수 있도록 시스템의 골격 코드 및 프로토타입 형태의 시스템을 자동 생성하는 빌더를 설계하고 구현한다. 생성되는 프로토타입 시스템에서는 커스텀 태그 및 재사용 가능한 빈을 정의하고 XML, DOM, 국제화, 지역화 등을 지원하도록 작성되어 커스텀 태그 및 빈의 추가 및 변경에 의해 웹 애플리케이션의 기능을 변경시키고 성능을 향상시키는 것이 용이하게 된다. 본 연구에서 설계하고 구현한 Model 2 기반 프로토타입 자동생성 도구는 웹 애플리케이션 개발시에 활용되어 생산성 향상에 기여할 수 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.97-102
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• 2013

Objective: The aim of this study was to develop an automated computer-aided diagnostic system for diagnosis of thyroid cancer pattern in fine needle aspiration cytology (FNAC) microscopic images with high degree of sensitivity and specificity using statistical texture features and a Support Vector Machine classifier (SVM). Materials and Methods: A training set of 40 benign and 40 malignant FNAC images and a testing set of 10 benign and 20 malignant FNAC images were used to perform the diagnosis of thyroid cancer. Initially, segmentation of region of interest (ROI) was performed by region-based morphology segmentation. The developed diagnostic system utilized statistical texture features derived from the segmented images using a Gabor filter bank at various wavelengths and angles. Finally, the SVM was used as a machine learning algorithm to identify benign and malignant states of thyroid nodules. Results: The SVMachieved a diagnostic accuracy of 96.7% with sensitivity and specificity of 95% and 100%, respectively, at a wavelength of 4 and an angle of 45. Conclusion: The results show that the diagnosis of thyroid cancer in FNAC images can be effectively performed using statistical texture information derived with Gabor filters in association with an SVM.

• Journal of the Institute of Electronics Engineers of Korea TE
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• 제42권3호
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• pp.39-44
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• 2005

In this paper, we use the 5-ary frequency shift keying method for robust powerline communication. To transmit the data by the 3-ary carrires among 5-ary carrirers and three carriers are 115kHz, 120kHz and 125kHz. Each time of three carrires is 0.33ms and total transmitting time duration from zero crossing point has 1ms. We use the dummy carriers which are 50kHz and 350kHz for monitoring the powerline channel state, dummy signal duration is received during 1ms. Experimentation result is shown that the implemented PLC transceiver has better than chirp transceiver at the capacitive load testing in spite of low transmission power.

• Journal of Korean Academy of Nursing
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• 제37권2호
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• pp.227-241
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• 2007

Background. Although research has established the existence of an association between smoking and depression among adolescents, researchers have not reached consensus on the nature of the association. Objectives. The purpose of this paper is to review the literature, to examine the nature of the relationship between smoking and depression in adolescence, and to suggest future research directions. Methods. A literature search was conducted from the following six databases: (a) Ovid MEDLINE, (b) CINAHL, (c) PubMed Unrestricted, (d) PsycINFO, (e) ERIC, and (f) Sociological Abstracts. The combinations of the words, "depression," "smoking," "tobacco," "adolescent," and "teen" were used for keyword searches to find relevant articles. Results. In 47 of 57 studies, significant associations between smoking and depression were found. However, these significant relationships may either be spurious or unrelated to depression because a substantial number of studies did not adjust for confounders or did not use validated instruments to measure depression. Additionally, if the relationship is causal, its direction remains controversial. Five relationships have been suggested: (a) Depression causes smoking, (b) smoking causes depression, (c) there is a bidirectional relationship between smoking and depression, (d) smoking and depression occur due to confounders, and (e) subgroups with different relationships between the two conditions exist. Conclusions. It is necessary to further explore the relationship between smoking and depression. Future research should consider the need for: (a) longitudinal research designs, (b) more accurate measurement of depression, and (c) the control of confounders between smoking and depression.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.523-523
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• 2000

We have developed a method to build time series prediction models by Genetic Programming (GP). Our proposed CP includes two new techniques. One is the parameter optimization algorithm, and the other is the new mutation operator. In this paper, the sunspot prediction experiment by our proposed CP was performed. The sunspot prediction is good benchmark, because many researchers have predicted them with various kinds of models. We make three experiments. The first is to compare our proposed method with the conventional methods. The second is to investigate about the relation between a model-building period and prediction precision. In the first and the second experiments, the long-term data of annual sunspots are used. The third is to try the prediction using monthly sunspots. The annual sunspots are a mean of the monthly sunspots. The behaviors of the monthly sunspot cycles in tile annual sunspot data become invisible. In the long-term data of the monthly sunspots, the behavior appears and is complicated. We estimate that the monthly sunspot prediction is more difficult than the annual sunspot prediction. The usefulness of our method in time series prediction is verified by these experiments.