• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.399-401
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• 2013

In this paper, we present the method to impove the performance by using iterative decoding in LDPC codes with 8-PSK modulation. Iterative decoding is the technique that improve the performance after the input signals of receiver are re-calculated by using the soft decision output of decoder. DVB-S2 system with 8-PSK modulation based on iterative decoding had a better performance than DVB-S2 with 8-PSK modulation over Gaussian channels.

• Journal of Life Science
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• v.32 no.9
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• pp.690-697
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• 2022

This study was conducted to analyze genome of red sea cucumber and to use it as basic data for the development of genetic markers for red sea cucumber. Microsatellite marker analysis of Ulleungdo_normal and Ulleungdo_native red sea cucumbers revealed that dinucleotide simple sequence repeats (SSRs) had the highest ratio, at 81.3~81.4%, and the number of the detected SSRs tended to decrease as the number of repeating sequence units in SSRs increased. In general, microsatellites with between 5 and 10 iterations were most common. As the size of the SSR repeating sequence units increased, the SSR iterations gradually decreased. The di-, tri-, and tetra-nucleotides in SSRs were detected in the highest numbers as (AT)₅, (AAT)₅, and (AAAT)₅, respectively. (CG) and (CCG) had very low frequencies compared to the numbers of other repeating SSR units. The numbers of di-and tri-nucleotide repeats were up to 35 and 32, respectively, and then increased discontinuously up to 44 and 43 repeats, respectively. Tetra-, penta-, and hexa-nucleotides in SSRs occurred in numbers up to 25, 21 and 14, respectively. This analysis of red sea cucumber indicated that it maintains its own repetition sequence and repetition number; therefore, we suggest that using it as basic data for molecular marker will be possible in future research.

• Proceedings of the Korean Statistical Society Conference
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• 2000.11a
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• pp.261-266
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• 2000

이변량 반복측정자료에서 Chinchilli 등(1996)이 제안한 가중일치상관계수는 두 변수의 일치성을 나타내는 측도이다. 기존에 제안된 가중일치상관계수 추정법은 변동효과 및 측정오차의 분산성분을 각각 최소제곱법으로 비편향 추정하여 구하는 것이다. 본 연구에서는 반복측정자료의 주변 우도함수를 설정한 후, 우도함수에 기초한 분산성분을 구하여 가중일치상관계수를 추정하는 방법을 제안한다. 이때, 각 분산성분은 유사/의사 우도함수 및 사후 분포에서 반복시행을 통하여 구해진다.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.44-45
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• 2000

GHz 급의 아주 높은 반복율을 가지면서, 피코초 단위의 펄스 열을 발진시키는 레이저를 만들기 위해 능동형 모드록킹 방법을 이용하였다. 이 방법은 공진기안에 광 변조기를 삽입하고, RF 신호를 가하여 시간적으로 공진기내에서의 손실을 변화시키는 방법이다.$^{(1)}$ 공진기 길이를 충분히 길게 하면서도 고 반복율을 가지는 레이저를 만들기 위해 조화 모드록킹 방법을 사용했는데, 이는 레이저 펄스의 반복율을 공진기 길이에 의한 기본 반복율의 정수배가 되도록 하는 방법이다.$^{(2),(3)}$ 3차 조화 모드록킹 방법을 이용한 Nd:YLF 레이저 시스템을 그림 1에서 나타내었다. (중략)

• Proceedings of the Korean Statistical Society Conference
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• 2005.11a
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• pp.91-96
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• 2005

다차원층화에서 선형계획법을 이용한 표본배정 방법은 Winkler(1990, 2001), Sitter와 Skinner(1994, 2002)가 제안하였다. 이 방법들은 표본크기가 층 개수보다 크지 않는 경우에 공통적으로 선형계획법을 이용하여 표본배정을 실시하였다. 반복 비율 적합방법(IPF), 일반화 반복 비율 적합(GIFP), SS 방법을 통해 셀 값을 결정하고 선형계획법을 이용하여 표본의 배정확률을 통해 표본배정을 실시한다. 이 3가지 방법들로 표본을 배정하고 평균 및 분산추정량을 비교한다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.6 s.336
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• pp.9-16
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• 2005

It is well blown about the fact that turbo code has better the BER performance as the number of decoding iterations increases in the AWGN channel environment. However, as the number of decoding iterations is increased under the several channel environments, any further iteration results in very little improvement, and it requires much delay and computation in proportion to the number of decoding iterations. In this paper, it proposes the efficient iterative decoding stop criterion algorithm which can largely reduce the computation and the average number of decoding iterations of turbo code. Through simulations, it is verifying that the proposed algorithm can efficiently stop the iterative decoding by using the variance value of LLR and can largely reduce the computation and the average number of decoding iterations without BER performance degradation. As a result of simulation, the computation for the proposed algerian is reduced by about $40\%$ compared to conventional CE algorithm. The average number of decoding iterations for the proposed algorithm is reduced by about $9.94\%$ and $8.32\%$ compared to conventional HDA and SCR algorithm respectively, and by about $2.16\%{\~}7.84\%$ compared to conventional CE algorithm.

• Korean Journal of Cognitive Science
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• v.11 no.3_4
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• pp.83-93
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• 2000

The effect of immediate and delayed recognition memory on event-related potential (ERP) was studied using a continuous recognition memory task and event-related potential (ERP). Among 240 stimulus words 40 words were not repeated. 100 were immediately repeated and 100 were repeated after 5 intervening words. All words presented only once during the experiment were referred to as new words. Subjects responded faster and more accurately to words repeated immediately than to new words a and to those repeated after intervening words. In terms of ERP results the immediately repeated words were associated with large P300 amplitude, early P300 latency and a absence of N400. while words repeated after a delay were associated with small P300 a amplitude. late P300 latency and the presence of N400. N400 was elicited only to new w words and to those repeated after a delay. The general morphology of the waveform was s similar for three stimulus-presentation conditions until around 3l0ms after the onset of stimulus. These results indicate that immediate and delayed recognition memory could be dissociated into two distinct processes possibly being mediated by different cerebral mechanism, and the dissociation between two types of recognition memory emerges around 3l0ms poststim'ulus. The immediate and delayed recognition memory for words are considered in terms of template matching and memory searching.

• The Journal of Engineering Geology
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• v.16 no.3 s.49
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• pp.235-244
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• 2006

Granite cores were sampled within Korea Atomic Energy Research Institute and cyclic loadings up to 1550 cycles were applied. Microcrack development in samples due to cyclic loading was estimated using Acoustic Emission(AE) method. AE showed two different types depending on numbers of cycle. Type 1 appeared at low cycles and had low energy and diverse frequencies, while type 2 appeared at high cycles and had high energy and uniform frequency. AE property of type 1 indicates voids and pre-existing microcracks in samples may close or propagate up to certain length. Microcracks may be sheared or closed during loading and are recovered from shear or opened during unloading when AE of type 2 were measured. P wave velocities and Felicity ratios were measured at 50, 150, 350, 750, 1550 cycles. P wave velocities were almost the same regardless of number of cycles applied. However, Felicity ratios were much lower than 0.9, indicating that microcracks were developed within samples. This result indicates that Felicity ratio is a better tool than P wave velocity to estimate the damage of rock.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10C
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• pp.1387-1394
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• 2004

Turbo code, a kind of error correction coding technique, has been used in the field of digital mobile communication systems. And it is well known about the fact that turbo code has better the BER performance as the number of decoding iterations increases in the AWGN channel environment. However, as the number of decoding iterations is increased under the several channel environments, any further iteration results in very little improvement, and it requires much delay, computation and power consumption in proportion to the number of decoding iterations. In this paper, it proposes the efficient iterative decoding stop criterion algorithm which can largely reduce the average number of decoding iterations of turbo code. Through simulations, it is verifying that the proposed algorithm can efficiently stop the iterative decoding by using the variance value of error probability for the soft output value, and can largely reduce the average number of decoding iterations without BER performance degradation. As a result of simulation, the average number of decoding iterations for the proposed algorithm is reduced by about 2.25% ~14.31％ and 3.79％ ~14.38% respectively compared to conventional schemes, and power consumption is saved in proportion to the number of decoding iterations.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.2
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• pp.166-173
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• 2002

Purpose: Recurrent abdominal pain (RAP) is common, affecting between 7% and 25% of school-aged children and young adult. This study was designed to assess the relationship between RAP and depressive trends in school-aged children. Methods: In 1999, We surveyed 1,181 elementary school children (566 boys and 615 girls) whose ages ranged from 9 to 12 years. The degree of depression was compared between the group with RAP and normal control group without RAP according to Korean Children's Depression Inventory (CDI) of Kovacs and Beck. Results: The number of the group with RAP was significantly higher in female (25.7%) than in male (18.9%). The most common site of abdominal pain was periumbilical. The mean depression score in the group with RAP was higher than that of the control group. The depression score was significantly higher in the group with RAP who has frequently pain and additional symptoms. The depression score was significantly higher in the group with RAP who prefered to play alone, did not enjoy going to school and had few friends than in the group with RAP who had a lot of friends, had active and meticulous characters. The depression scores were not significantly different according to the duration of abdominal pain, the onset time of pain, and the day of pain in the group with RAP. Conclusion: The depression score of the group with RAP was higher than that of normal group. So, there is relatively a specific association between childhood RAP and depression in school aged children. It is good for physicians to consider psychological support in the treatment of childhood RAP.