• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.767-776
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• 2006

Corresponding author:Deukhwan Lee, Department of Animal Life Resources, Hankyong National Univ. Seokjeong-dong Anseong-si Gyeonggi-do, Rep. of Korea 456-749Tel: 031-670-5091, Fax: 031-676-5091, E-mail : dhlee@hknu.ac.krGeneral performance with including environmental and management effects on linear type traits in Holstein cows were investigated. 115,646 valid records measured from cows over 1 yrs of age by Korean Animal Improvement Association from 2000 to 2004 were used for this study. Farm, appraisal year-month, appraisal person should affect linear type and scoring traits. Most of type traits and scoring traits would be significantly affected by parity and lactation stage after absorbing farm-appraisal year-month-person effects. Otherwise, some traits such as traits related to udder would be affected by registration criteria. However, interval of appraisal time and milking time would not affect these traits. The scores related to udder, teat placement and foot angle would be positively related to parity. Final score would be optimized at cows of 2nd and 3rd parities. Dairy form, front teat placement, rear udder height, rear udder width and final score would show similar to pattern of lactation curve at lactation stage. Dairy capacity composite index would also show similar to lactation curve. This result would be indicated that more concise standardizing system for linear type scoring rules would be needed. Furthermore, correcting system for parity and lactation stage would be needed because this factor should affect physiological status, specially, udder status.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.409-416
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• 2017

In this paper, we consider a framework of compressed sensing over finite fields. One measurement sample is obtained by an inner product of a row of a sensing matrix and a sparse signal vector. A recovery algorithm proposed in this study for sparse signals based probabilistic decoding is used to find a solution of compressed sensing. Until now compressed sensing theory has dealt with real-valued or complex-valued systems, but for the processing of the original real or complex signals, the loss of the information occurs from the discretization. The motivation of this work can be found in efforts to solve inverse problems for discrete signals. The framework proposed in this paper uses a parity-check matrix of low-density parity-check (LDPC) codes developed in coding theory as a sensing matrix. We develop a stochastic algorithm to reconstruct sparse signals over finite field. Unlike LDPC decoding, which is published in existing coding theory, we design an iterative algorithm using probability distribution of sparse signals. Through the proposed recovery algorithm, we achieve better reconstruction performance as the size of finite fields increases. Since the sensing matrix of compressed sensing shows good performance even in the low density matrix such as the parity-check matrix, it is expected to be actively used in applications considering discrete signals.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.8
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• pp.1-11
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• 2012

The multi-code spread spectrum communication system, which spreads data bit stream by multiplexing orthogonal codes, can transmit data in high rate. However it needs the high-cost good linear amplifier because of the multi-level output signal. In order to overcome this drawback several systems making the amplitude of output signal constant with Walsh codes have been proposed. Recently constant amplitude pre-coded multi-code spread spectrum systems using extended m-sequence have been proposed. In this paper we consider an extended m-sequence based constant amplitude multi-code spread spectrum system with code set partitioning. By grouping the orthogonal codes into 4 subsets, not only is the computational complexity of the transceiver reduced but BER performance also improves. It has been shown that parity checking on four detected codes at the receiver can correct code detection error and result in BER performance enhancement. In this paper we propose a improved parity check receiver. We carried out computer simulation to verify feasibility of the proposed algorithm.

• Journal of Preventive Medicine and Public Health
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• v.49 no.6
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• pp.349-366
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• 2016

Objectives: We conducted a systematic review and meta-analysis to summarize current evidence regarding the association of parity and duration of breastfeeding with the risk of epithelial ovarian cancer (EOC). Methods: A systematic search of relevant studies published by December 31, 2015 was performed in PubMed and EMBASE. A random-effect model was used to obtain the summary relative risks (RRs) and 95% confidence intervals (CIs). Results: Thirty-two studies had parity categories of 1, 2, and ${\geq}3$. The summary RRs for EOC were 0.72 (95% CI, 0.65 to 0.79), 0.57 (95% CI, 0.49 to 0.65), and 0.46 (95% CI, 0.41 to 0.52), respectively. Small to moderate heterogeneity was observed for one birth (p<0.01; Q = 59.46; $I^2=47.9%$). Fifteen studies had breastfeeding categories of <6 months, 6-12 months, and >13 months. The summary RRs were 0.79 (95% CI, 0.72 to 0.87), 0.72 (95% CI, 0.64 to 0.81), and 0.67 (95% CI, 0.56 to 0.79), respectively. Only small heterogeneity was observed for <6 months of breastfeeding (p = 0.17; Q = 18.79, $I^2=25.5%$). Compared to nulliparous women with no history of breastfeeding, the joint effects of two births and <6 months of breastfeeding resulted in a 0.5-fold reduced risk for EOC. Conclusions: The first birth and breastfeeding for <6 months were associated with significant reductions in EOC risk.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.9
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• pp.1166-1176
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• 1999

연속 매체, 특히 비디오 데이타에 대한 일반 사용자 연산에는 재생뿐만 아니라 임의 속도 탐색 연산, 정지 연산, 그리고 그 외 다양한 연산이 있다. 이 연산 중에서 원하는 화면을 빨리 찾는 데에 유용한 고속 전진(FF: fast-forward)과 고속 후진(FB: fast-backward)은 재생 연산과는 달리 비순차적인 디스크 접근을 요구한다. 이러한 경우에 디스크 부하가 균등하지 않으면 일부 디스크에 접근이 편중되어 서비스 품질이 떨어진다. 본 논문에서는 디스크 배열을 이용한 저장 시스템에서 디스크 접근을 고르게 분산시키기 위하여 '소수 라운드 로빈(PRR: Prime Round Robin)' 방식으로 연속 매체를 디스크에 배치하는 기법에서 문제가 됐던 낭비된 디스크 저장 공간을 신뢰도 향상을 위해서 사용하는 '그룹화된 패리티를 갖는 소수 라운드 로빈(PRRgp: PRR with Grouped Parities)' 방식을 제안한다. 이 기법은 PRR 기법처럼 임의 속도 검색 연산에 있어서 디스크 배열을 구성하는 모든 디스크의 부하를 균등하게 할뿐만 아니라 낭비됐던 디스크 저장 공간에 신뢰도를 높이기 위한 패리티 정보를 저장함으로서 신뢰도를 향상시킬 수 있다. 신뢰도 모델링 방법으로 조합 모델과 마르코프 모델을 이용해서 결함발생율과 결함복구율을 고려한 신뢰도를 산출하고 비교.분석한다. PRR 기법으로 연속 매체를 저장하고 낭비되는 공간에 패리티 정보를 저장할 경우에 동시에 두 개 이상의 결함 발생 시에 그 결함으로부터 복구가 불가능하지만 PRRgp 기법에서는 약 30% 이상의경우에 대해서 동시에 두 개의 결함 발생 시에 저장한 패리티 정보를 이용한 복구가 가능할 뿐만 아니라 패리티 그룹의 수가 두 개 이상인 경우에는 두 개 이상의 결함에 대해서도 복구가 가능하다.Abstract End-user operations on continuous media (say video data) consist of arbitrary-rate search, pause, and others as well as normal-rate play. FF(fast-forward) / FB(fast-backward) among those operations are desirable to find out the scene of interest but they require non-sequential access of disks. When accesses are clustered to several disks without considering load balance, high quality services in playback may not be available. In this paper, we propose a new disk placement scheme, called PRRgp(Prime Round Robin with Grouped Parities), with enhanced reliability by using the wasted disk storage space in an old one(PRR: Prime Round Robin), in which continuous media are placed on a disk array based storage systems to distribute disk accesses uniformly. The PRRgp can not only achieve load balance of disks consisting of a disk array under arbitrary-rate search like PRR, but also improve reliability by storing parity information on the wasted disk space appropriately. We use combinatorial and Markov models to evaluate the reliability for a disk array and to analyze the results. When continuous media like PRR are placed and parity information on the wasted disk space is stored, we cannot tolerate more than two simultaneous faults. But they can be recovered by using stored parity information for about 30 percent as a whole in case of PRRgp presented in this paper. In addition, more than two faults can be tolerated in case there are more than two parity groups.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.222-237
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• 2002

Effects of high and low levels of feeding with or without protected protein on the performance of lactating goats were studied. Twenty four German Fawn goats either from 1st ($43.37{\pm}3.937$ kg and 2 year old) or 3rd $62.64{\pm}6.783$ kg and 4-5 year old) parity were used for the trial. Feeding levels were 7.2 (I) and 5.2 (II) MJ ME/litre of milk of 3.5% fat in addition to that of the maintenance allowance. At each feeding level, diet had either unprotected (U) or formaldehyde protected (P) soya-meal. Thus, four diets were IU, IP, IIU and IIP, having six animals in each. The diets were composed of hay and pellet (10:4:1 of beet pulp : barley : soya-meal). Effect of feeding level, protein protection, parity, health status and kid number on intake, milk yield, milk composition, growth rate of goats were recorded across the 21 weeks of study. High feeding level resulted increase (p<0.001) in estimated metabolizable energy (ME) and metabolizable protein (MP) availability. Dietary inclusion of protected soya-meal increased (p<0.001) the estimated MP but not the ME availability. Animals in 1st parity ate more (p<0.001) DM (111 vs. 102 g/kg $W^{0.75}$/d) than those in 3rd parity. Animals with twin kids (110 g/kg $W^{0.75}$/d) had higher (p<0.001) DM intake than those with single kid (102 g/kg $W^{0.75}$/d). Fat (4%) corrected milk (FCM) yield was not effected by high (1,924 g/d) or low (1,927 g/d) feeding level but increased (p<0.001) with protected (2,166 g/d) compared with unprotected (1,703 g/d) soya-meal. FCM yield for four dietary combinations were 1,806, 2,078, 1,600 and 2,254 g/d for diets IU, IP, IIU and IIP, respectively. For unit increase (g) in estimated MP availability relative to ME (MJ) intake, FCM yield increased ($1,418{\pm}275.6$) g daily ($r^2$=0.58; p<0.001). Milk fat (3.14 vs. 3.54%; p<0.001) and protein (2.94 vs. 3.04% p<0.05) contents were lower at high than the low feeding level. Protected protein increased (p<0.001) the fat, lactose and net energy (NE) content of milk. Milk urea concentration of 175, 183, 192 and 204 mg/l for diets IU, IP, IIU and IIP, respectively indicated lower RDP content of these diets. The RDP contents were 6.97, 6.70, 7.30 and 6.83 g/MJ of ME for diets IU, IP, IIU and IIP, respectively. Live weight change over the experimental period were 41, 6, 17 and 19 g/d. Absence of any positive response of high feeding was probably due to inefficient rumen fermentation resulting from inadequate RDP supply. Protected protein improved production performance apparently by increasing MP:ME ratio in the absorbed nutrient.

• Korea journal of population studies
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• v.34 no.1
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• pp.1-25
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• 2011

There are two main purposes in this study. First, we compare the effects of wives' characteristics with the effects of the husbands' characteristics on the induced abortion. Second, we analyze whether the determinants of the induced abortion have changed according to parity and conception period. The main findings are follows. First, both wives' and husbands' socioeconomic characters have insignificant effects on the induced abortion at parity 0, in the 1997 and 2000 Korean Fertility Survey data. Second, during the periods of the lowest-low fertility, after 2000 in Korea, wives' employments have positive effects at parity 0 and 1, while husbands' educational levels have negative effects at parity 1 on the induced abortion. The implications are as follows. First, having children had been the universal social phenomenon before 2000 in Korea. however, after 2000, reproductions have become the women's choice, lather than the duty of married women. Women must weight the balance between the benefits and the costs of children so that women's fertility behaviors become a rational choice. Women's employment is the most important factor in these rational calculations. Second, both Western individualism and the traditional Korean familism have significant effects on the fertility behavior and the induced abortions in Korea. This rejects the diffusion theory, which tells that the traditional familism must be replaced by the Western individualism in order to decline the fertility rates in developing countries.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.135-149
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• 2020

Artificial intelligences are changing world. Financial market is also not an exception. Robo-Advisor is actively being developed, making up the weakness of traditional asset allocation methods and replacing the parts that are difficult for the traditional methods. It makes automated investment decisions with artificial intelligence algorithms and is used with various asset allocation models such as mean-variance model, Black-Litterman model and risk parity model. Risk parity model is a typical risk-based asset allocation model which is focused on the volatility of assets. It avoids investment risk structurally. So it has stability in the management of large size fund and it has been widely used in financial field. XGBoost model is a parallel tree-boosting method. It is an optimized gradient boosting model designed to be highly efficient and flexible. It not only makes billions of examples in limited memory environments but is also very fast to learn compared to traditional boosting methods. It is frequently used in various fields of data analysis and has a lot of advantages. So in this study, we propose a new asset allocation model that combines risk parity model and XGBoost machine learning model. This model uses XGBoost to predict the risk of assets and applies the predictive risk to the process of covariance estimation. There are estimated errors between the estimation period and the actual investment period because the optimized asset allocation model estimates the proportion of investments based on historical data. these estimated errors adversely affect the optimized portfolio performance. This study aims to improve the stability and portfolio performance of the model by predicting the volatility of the next investment period and reducing estimated errors of optimized asset allocation model. As a result, it narrows the gap between theory and practice and proposes a more advanced asset allocation model. In this study, we used the Korean stock market price data for a total of 17 years from 2003 to 2019 for the empirical test of the suggested model. The data sets are specifically composed of energy, finance, IT, industrial, material, telecommunication, utility, consumer, health care and staple sectors. We accumulated the value of prediction using moving-window method by 1,000 in-sample and 20 out-of-sample, so we produced a total of 154 rebalancing back-testing results. We analyzed portfolio performance in terms of cumulative rate of return and got a lot of sample data because of long period results. Comparing with traditional risk parity model, this experiment recorded improvements in both cumulative yield and reduction of estimated errors. The total cumulative return is 45.748%, about 5% higher than that of risk parity model and also the estimated errors are reduced in 9 out of 10 industry sectors. The reduction of estimated errors increases stability of the model and makes it easy to apply in practical investment. The results of the experiment showed improvement of portfolio performance by reducing the estimated errors of the optimized asset allocation model. Many financial models and asset allocation models are limited in practical investment because of the most fundamental question of whether the past characteristics of assets will continue into the future in the changing financial market. However, this study not only takes advantage of traditional asset allocation models, but also supplements the limitations of traditional methods and increases stability by predicting the risks of assets with the latest algorithm. There are various studies on parametric estimation methods to reduce the estimated errors in the portfolio optimization. We also suggested a new method to reduce estimated errors in optimized asset allocation model using machine learning. So this study is meaningful in that it proposes an advanced artificial intelligence asset allocation model for the fast-developing financial markets.

• Proceedings of the KSCN Conference
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• 1998.05a
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• pp.63-63
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• 1998

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.134-134
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• 2004