• Communications for Statistical Applications and Methods
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• v.22 no.5
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• pp.415-434
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• 2015

In this paper we overview the literature on common features analysis of economic time series. Starting from the seminal contributions by Engle and Kozicki (1993) and Vahid and Engle (1993), we present and discuss the various notions that have been proposed to detect and model common cyclical features in macroeconometrics. In particular, we analyze in details the link between common cyclical features and the reduced-rank regression model. We also illustrate similarities and differences between the common features methodology and other popular types of multivariate time series modelling. Finally, we discuss some recent developments in this area, such as the implications of common features for univariate time series models and the analysis of common autocorrelation in medium-large dimensional systems.

• East Asian Economic Review
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• v.27 no.4
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• pp.327-346
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• 2023

In the recent 20 years, the capital flows between Korea and European Union have increased and diversified. In particular, the business cycles of two economies have shown similar patterns since the Global Financial Crisis. This study examines both trends and investigates the roles of finance and trade on business cycle co-movements between two economies. The empirical results show that the business cycles can diverge due to either the common shocks or the country-specific shocks. Furthermore, financial integration increases the business cycle co-movements driven by both the country-specific shocks and the common shocks between two economies.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.1
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• pp.38-43
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• 2016

Objective: The number of assisted reproductive technology (ART) clinics, ART cycles, clinical pregnancy rate (CPR), and number of newborns conceived using ART have steadily increased in South Korea. This aim of this study was to describe the status of ART in South Korea between January 1 and December 31, 2011. Methods: A localized online survey was created and sent to all available ART centers via email in 2015. Fresh embryo transfer (FET) cases were categorized depending on whether standard in vitro fertilization, intracytoplasmic sperm injection (ICSI), or half-ICSI procedures were used. Thawed embryo transfer (TET) and other related procedures were surveyed. Results: Data from 36,990 ART procedures were provided by 74 clinics. Of the 30,410 cycles in which oocytes were retrieved, a complete transfer was performed in 91.0% (n=27,683). In addition, 9,197 cycles were confirmed to be clinical pregnancies in the FET cycles, representing a pregnancy rate of 30.2% per oocyte pick-up and 33.2% per ET. The most common number of embryos transferred in the FET procedures was three (38.1%), followed by two (34.7%) and one (14.3%). Of the 8,826 TET cycles, 3,137 clinical pregnancies (31.1%) were confirmed by ultrasonography. Conclusion: While the overall clinical pregnancy rate for the TET cycles performed was lower than the rate reported in 2010 (31.1% vs. 35.4%), the overall CPR for the FET cycles was higher than in 2010 (33.2% in 2011 and 32.9% in 2010). The most common number of embryos transferred in FET cycles was three, as was the case in 2010.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.1
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• pp.8-13
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• 2015

Objective: Great advances have been made in the field of assisted reproductive technology (ART) since the first in vitro fertilization (IVF) baby was born in Korea. This study was designed to report on the current status of ART therapy in South Korea between January 1 and December 31 of 2010. Methods: A revised survey, originally developed by the International Committee Monitoring Assisted Reproductive Technologies, was sent to all available ART centers via email in 2013. Fresh embryo transfer (FET) cases were categorized into standard IVF or intracytoplasmic sperm injections. These cases, the thawing embryo transfer (TET) cases, and other related procedures were surveyed. Results: Data from 30,785 ART procedures were provided by 78 clinics. Of the 28,200 cycles in which oocytes were retrieved, 92.2% of these cycles were completely transferred. In addition, 8,075 cycles were confirmed to be clinical pregnancies in the FET cycles, which represent a pregnancy rate of 28.6% per oocyte pick-up and 31.1% per embryo transfer. The most common number of embryos transferred in the FET was three embryos (37.3%) followed by two embryos (36.3%) and one embryo (14.0%). Of the 6,648 TET cycles transferred, 2,356 clinical pregnancies were confirmed by ultrasonography. The most common number of embryos in the TET group was two embryos (43.4%) followed by three embryos (25.4%) and one embryo (18.9%). Conclusion: The clinical pregnancy rate per transfer in the FET cycles was similar in 2009 and 2010. Among the FET cycles where one or two embryos were transferred, the clinical pregnancy rate per transfer slightly increased from 2009 (28.7%) to 2010 (32.9%).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.119-128
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• 2004

In this paper, a low-power 8-point DCT structure is proposed using add and shift operations. Proposed structure adopts 4 cycles for complete 8-point DCT in order to minimize size of hardware and to enable high-speed processing. In the structure, hardware for the first cycle can be shared in the next 3 cycles since all columns in the DCT coefficient matrix are common except sign. Conventional DCT structures implemented with only add and shift operation use CSD(Canonic Signed Digit) form coefficients to reduce the number of adders. To reduce the number of adders further, we propose a new structure using common sub-expression sharing techniques. With this techniques, the proposed 8-point DCT structure achieves 19.5% adder reduction comparison to the conventional structure using only CSD coefficient form.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.2
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• pp.96-104
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• 2017

Objective: This study aimed to compare the clinical outcomes between in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in sibling oocytes. Additionally, we evaluated whether the implementation of split insemination contributed to an increase in the number of ICSI procedures. Methods: A total of 571 cycles in 555 couples undergoing split insemination cycles were included in this study. Among them, 512 cycles (89.7%) were a couple's first IVF cycle. The patients were under 40 years of age and at least 10 oocytes were retrieved in all cycles. Sibling oocytes were randomly allocated to IVF or ICSI. Results: Total fertilization failure was significantly more common in IVF cycles than in ICSI cycles (4.0% vs. 1.4%, p<0.05), but the low fertilization rate among retrieved oocytes (as defined by fertilization rates greater than 0% but < 30%) was significantly higher in ICSI cycles than in IVF cycles (17.2% vs. 11.4%, p<0.05). The fertilization rate of ICSI among injected oocytes was significantly higher than for IVF ($72.3%{\pm}24.3%$ vs. $59.2%{\pm}25.9%$, p<0.001), but the fertilization rate among retrieved oocytes was significantly higher in IVF than in ICSI ($59.2%{\pm}25.9%$ vs. $52.1%{\pm}22.5%$, p<0.001). Embryo quality before embryo transfer was not different between IVF and ICSI. Although the sperm parameters were not different between the first cycle and the second cycle, split insemination or ICSI was performed in 18 of the 95 cycles in which a second IVF cycle was performed. Conclusion: The clinical outcomes did not differ between IVF and ICSI in split insemination cycles. Split insemination can decrease the risk of total fertilization failure. However, unnecessary ICSI is carried out in most split insemination cycles and the use of split insemination might make ICSI more common.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.1
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• pp.47-51
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• 2017

Objective: This study was designed to report the status of assisted reproductive technology (ART) therapy in South Korea between January 1, 2012 and December 31, 2012. Methods: A localized online survey, originally developed by the International Committee Monitoring Assisted Reproductive Technologies, was first launched and provided to all available ART centers via email in 2015. Fresh embryo transfer (FET) cases were categorized as standard in vitro fertilization, intracytoplasmic sperm injection (ICSI), or half-ICSI. Thawed embryo transfer (TET) and other related procedures, including surgical sperm retrieval, were surveyed. Results: Data from 33,956 ovum pick-up procedures were provided by 75 clinics in 2012. Of the 33,088 cycles in which ovums were retrieved, a complete transfer was performed in 90.5% (29,932 cycles). In addition, 10,079 FET cycles were confirmed to have resulted in clinical pregnancy, representing a pregnancy rate of 30.5% per ovum pick-up and 33.7% per ET. The most common number of embryos transferred in FET was 2 (41.6%), followed by 3 (34.0%), and non-elective single ETs (10.0%). Of the 10,404 TET cycles in which transfer was completed, 3,760 clinical pregnancies (36.1%) were confirmed by ultrasonography. Conclusion: The overall clinical pregnancy rate for FET and TET cycles in 2012 was higher than in 2011 (33.7% vs. 33.2% and 36.1% vs. 31.1%, respectively). The most common number of embryos transferred in FET cycles was 2, unlike in 2011.

• Current Optics and Photonics
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• v.3 no.1
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• pp.8-15
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• 2019

We describe a common optical system that merges a LADAR system, which generates a point cloud, and a more traditional imaging system operating in the LWIR, which generates image data. The optimum diameter of the entrance pupil was determined by analysis of detection ranges of the LADAR sensor, and the result was applied to design a common optical system using LADAR sensors and LWIR sensors; the performance of these sensors was then evaluated. The minimum detectable signal of the $128{\times}128-pixel$ LADAR detector was calculated as 20.5 nW. The detection range of the LADAR optical system was calculated to be 1,000 m, and according to the results, the optimum diameter of the entrance pupil was determined to be 15.7 cm. The modulation transfer function (MTF) in relation to the diffraction limit of the designed common optical system was analyzed and, according to the results, the MTF of the LADAR optical system was 98.8% at the spatial frequency of 5 cycles per millimeter, while that of the LWIR optical system was 92.4% at the spatial frequency of 29 cycles per millimeter. The detection, recognition, and identification distances of the LWIR optical system were determined to be 5.12, 2.82, and 1.96 km, respectively.

• Asia pacific journal of information systems
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• v.4 no.2
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• pp.83-130
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• 1994

Software development of large scale program such as Operating System or University Total Information System is lengthy and costly process. In order to reduce cost, time and risk, there is currentry general acceptance of the need for Software Reuse System during the whole development cycles. In this paper, (from a practical point of view), the problem of existing reuse system methodology is analyzed and an implement method of software reuse system is presented. Also using this method Application Program Reuse System(APRS) which supports all phase of software life cycles is designed and implemented. This application program reuse system which is based on common language is considerably shown to reduce communication Error of requirement specification between systems analyst and end-user.

• Korean Journal of Clinical Pharmacy
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• v.14 no.2
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• pp.61-70
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• 2004

Heptaplatin is a new platinum derivative with antitumor activity against gastric cancer. Preclinical studies showed that it is less toxic than other platinum analogues. The purpose of this study is to evaluate the efficacy and toxicity of the combination therapy of heptaplatin and 5-fluorouracil in Korean advanced gastric cancer patients. This study was investigated retrospectively. The patients group consisted of 65 advanced gastric cancer patients with no prior radiotherapy. All patients received heptaplatin $400\;mg/m^2$ by 2-3 hour infusion on Day 1 and 5-FU $1000\;mg/m^2by 12-24 hour continuous infusion for 5 days. After the first cycle, subsequent doses were adjusted according to the toxicity. Courses were repeated every 28 days. As results, objective response occurred in 16 patients $(24.6\%)$. Two were complete and 14 were partial response. Median progression free survival was 32 weeks with $29\%$ of patients progression free at 1 year. The most common hematologic toxicity was anemia. Grade 3 or 4 anemia was seen at $2.7\%$ of treatment cycles. Grade 3 or higher leucopenia was seen at $1.2\%$ of cycles. Grade 3 or 4 neutropenia and thrombocytopenia occurred at $6.1\%\;and\;1.5\%$ of cycles, respectively. The most common nonhematologic toxicity was proteinuria. Though no patients experienced grade 3 or 4 proteinuria, proteinuria was a considerable factor for this chemotherapy. Grade 3 or higher gastrointestinal toxicities were nausea and vomiting ($4.6\%$ of patients) and diarrhea ($1.5\%$ of patients). Grade 2 renal toxicity with elevation of serum creatinine was seen in $0.3\%$ of cycles, which is less than that of other platinum analogues. This study showed that combination therapy of heptaplatin and 5-FU have modest antitumor activity against advanced gastric cancer without severe renal toxicity.