• 한국통신학회논문지
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• 제29권1C호
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• pp.119-128
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• 2004

이 논문에서는 곱셈기를 사용하지 않고 덧셈기 만을 사용하여 DCT를 효과적으로 수행하는 저전력 구조를 제안하였다. 고속처리가 가능하면서도 구현 하드웨어의 크기를 최소화하기 위하여 8-point DCT를 4 cycle에 수행하는 구조를 사용하였다. 즉, 첫 번째 cycle에서 사용한 계수용 하드웨어를 두 번째부터 네 번째까지의 계산에서도 공통으로 사용할 수 있는 구조를 채택하였다. 덧셈기 만을 사용하는 기존의 구조들은 CSD(Canonic signed digit)형의 계수를 사용하여 덧셈의 수를 줄이고 있다. 본 논문에서는 Common subexpression sharing 방식을 채용함으로서 하드웨어를 더욱 감소시킬 수 있는 구조를 제안하였다. 그 결과 8-point DCT의 경우에 CSD 만을 사용한 구조와 비교하여 19.5%의 덧셈 수 감소 효과를 달성하였다.

• Clinical and Experimental Reproductive Medicine
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• 제22권2호
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• pp.211-220
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• 1995

Though the endometriosis is not always related with infertility, endometriosis causes infertility in some patients. There are many treatment modalities of infertile patients who have endometriosis. In recent years, Assisted Reproductive Technology(ART) have been widely accepted as being a useful tool for the treatment of infertile endometriotic patients. The objective of this study was to evaluate the outcome of ART in infertile endometriotic patients who have been carried out IVF-ET from Jan, 1992 to Dec, 1994 and to compare the results between COH/IUI and IVF-ET in the patients with endometriosis stage I. Tubal disease only patients were grouped(308 patient, 956 cycles) as a control. Endometriosis group was subdivided into 4 groups according to American Fertility Society classification; endometriosis stage I (45 patients, 61 cycles), stage II (26 patients, 39 cycles), stage III (26 pateitns, 37 cycles), stage IV (33 patients, 50 cycles). The outcomes of IVF-ET in endometriosis patients were as follows; The oocyte recovery rates were significantly lower in stage III, IV endometriosis. In case of stage III endometriosis, the fertilization rate was significantly lower than other stages of endometriosis. Clinical pregnancy rates per cycle were not different between the tubal group(22%) and the endometriosis group(25%). According to endometriosis stage, the implantation rate and clinical pregnancy rate were significantly lower in stage IV (5.6%, 16%) compared with other stages (I; 10.0%, 26%, II;9.8%, 31%, III;12.6%, 32%). It suggests that some factor like autoantibodies may inhibit implantation of embryos in stage IV endometriosis. To evaluate the possibility that simply increasing the number of gametes at the site of fertilization might account for pregnancies attributed to IVF-ET, the authors retrospectively analyzed the outcome of couples undergoing IUI during hMG cycles and CC cycles between 1992 and 1994 in the women with endometriosis stage 1. In case of stage I endometriosis, though the COH/IUI group showed lower FSH level and lesser age profile than IVF-ET group, IUI group has resulted in lower pregnancy rates(19.2%) compared with the IVF-ET group(26.2%). In conclusion, endometriotic infertile patients can get comparable pregnancy rates with the tubal factor infertility patients during IVF-ET program. Moreover even in stage I endometriosis, IVF-ET may be an more effective treatment modality than COH/IUI.

• Clinical and Experimental Reproductive Medicine
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• 제37권4호
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• pp.329-338
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• 2010

목적: 본 연구에서는 10개 이하의 2PN 접합자를 얻은 환자군에서 전핵 단계 배아의 동결보관이 누적 분만율을 증가시키는 지를 살펴보고자 하였다. 연구방법: 2003년 1월부터 2007년 12월까지 제일병원 아이소망센터를 내원하여 과배란 유도에 의해 체외수정 및 배아이식술을 시행한 주기를 후향적으로 비교 분석하였다. 본 연구에서는 일반적 체외수정법 또는 세포질내 정자주입술을 이용하여 수정을 시도한 후 20~22시간에 8개의 수정란을 확인하거나, 또는 전핵이 1개만 보이는 접합자와 발달지연 배아를 포함하여 수정란이 10개 미만인 138주기의 체외수정 및 배아이식 주기를 대상으로 분석하였다. 분석대상을 두 군으로 나누었으며 그룹 I (n=86)은 배아의 동결 없이 모든 수정란을 배양하여 3일째 이식한 군으로 하였으며, 그룹 II (n=52)는 전핵 시기에 일부 수정란을 동결하고 나머지를 배양하여 3일째 이식한 군으로 분류하였다. 두 군간 신선배아 이식주기와 그 다음 동결-해동 이식주기 후의 임상적 임신율과 누적 임신율을 각각 비교하였다. 결과: 비교 대상군 사이에 여성의 평균 나이, 획득 난자의 수 및 수정란의 수에서는 통계적 차이를 보이지 않았다. 배양된 배아의 수는 그룹 II ($5.2{\pm}0.5$)가 그룹 I $8.4{\pm}0.7$)에 비하여 유의하게 적었다 (p<0.01). 또한 이식한 배아의 수 역시 그룹 II ($3.3{\pm}0.6$)가 그룹 I ($3.6{\pm}0.6$)에 비하여 통계적으로 유의하게 적었다 (p<0.01). 신선주기 배아이식에서 ${\beta}$-hCG 양성을 보인 환자 수와 분만을 한 환자의 수는 그룹 I이 그룹 II에 비하여 약간 높은 양상을 보였다 (51.2 vs. 46.2% and 41.9 vs. 34.6%). 동결-해동 배아이식 후 누적 분만율을 비교하였을 때 그룹 I (48.8%)과 그룹 II (50.0%)에서 통계적으로 유의한 차이를 관찰할 수 없었다. 결론: 적은 수의 수정란을 얻은 환자군에서 일부 전핵 단계에서의 동결보관이 누적 분만율을 향상 시키는 효과를 확인할 수 없었다. 그러나 일부 수정란의 동결보관은 해당 신선주기에서 임신에 실패하였을 경우 환자에게 추가적인 배아이식 기회를 제공해 줄 수 있는 장점을 가지고 있는 것으로 생각된다.

• 한국작물학회지
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• 제20권
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• pp.134-141
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• 1975

필리핀 수도품종 BPI 76을 사용하여 생육경과에 따른 단일감응도의 변이, 출수에 필요한 최소단일처리구수 그리고 단일출수일수에 도달하는 단일처리회수 등을 검토하여 다음과 같은 결과를 얻었다. 1. 파종후 35일까지는 생육이 진전됨에 따라서 단일감응성이 예민하여 졌으며 35일 이상 생육한 벼의 단일감응성은 더 변함이 없었다. 2. 파종후 생육일수가 경과됨에 따라서 출수에 필요한 단일처리일수는 단축되었으며 단일처리기간이 연장됨에 따라서 출수까지의 일수가 어느정도까지는 단축되었다. 3. 공시품종 BPI 76이 완전출수하는데 필요한 최소단일처리회수는 파종부터 단일조건일때는 29회, 파종 30일후부터 단일조건일때는 12회이었고 파종 35일, 40일, 50일후부터 단일조건일 때는 모두 11회이었다. 4. 최단출수일수에 도달하는데 필요한 단일처리회수는 파종부터는 37회이사, 파종 30일후부터 25회이상 그리고 파종후 35일, 40일, 50일부터는 모두 21회이상이었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.261-262
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• 2018

In this study, the quality of recycled aggregate for concrete was investigated as the number of recycled aggregate crushing cycles, grinder and crusher, peeling and crushing. First, the quality of density, absorption ratio and solid content was improved as the separation distance decreased and the number of crushing increased, depending on the number of crushing of recycled aggregate and the distance between mantle and cone cave. The quality of density, absorption ratio and solid content was improved as the wire mesh used in striking plate and the number of hammers increased, depending on the type of striking plate and the number of hammers.

• Clinical and Experimental Reproductive Medicine
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• 제44권2호
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• pp.111-117
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• 2017

Objective: The aim of this study was to evaluate pregnancy outcomes and the live birth rate at 1-year age increments in women aged ${\geq}40years$ undergoing fresh non-donor in vitro fertilization (IVF) and embryo transfer (ET), and to identify predictors of success in these patients. Methods: This retrospective study was performed among women ${\geq}40years$ of age between 2004 and 2011. Of the 2,362 cycles that were conducted, ET was performed in 1,532 (73.1%). Results: The clinical pregnancy rate and live birth rate in women ${\geq}40years$ significantly decreased with each year of increased age (p<0.001). Maternal age (odds ratio [OR], 0.644; 95% confidence interval [CI], 0.540-0.769; p<0.001), basal follicle-stimulating hormone (FSH) levels (OR, 0.950; 95% CI, 0.903-0.999; p=0.047), the number of high-quality embryos (OR, 1.258; 95% CI, 1.005-1.575; p=0.045), and the number of transferred embryos (OR, 1.291; 95% CI, 1.064-1.566; p=0.009) were significant predictors of live birth. A statistically significant increase in live birth rates was seen when ${\geq}3$ embryos were transferred in patients 40 to 41 years of age, whereas poor pregnancy outcomes were seen in patients ${\geq}43years$ of age, regardless of the number of transferred embryos. Moreover, the cumulative live birth rate increased in patients 40 to 42 years of age with repeated IVF cycles, but the follicle-stimulating hormone in those ${\geq}43years$ of age rarely showed an increase. Conclusion: IVF-ET has acceptable outcomes in those < 43 years of age when a patient's own oocytes are used. Maternal age, basal FSH levels, and the number of high-quality embryos and transferred embryos are useful predictors of live birth.

• The Korean Journal of Physiology and Pharmacology
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• 제27권2호
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• pp.167-176
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• 2023

This study aims to explore the impact of Rehmannioside D (RD) on ovarian functions of rats with diminished ovarian reserve (DOR) and its underlying mechanisms of action. A single injection of cyclophosphamide was performed to establish a DOR rat model, and fourteen days after the injection, the rats were intragastrically administrated with RD for two weeks. Rat estrus cycles were tested using vaginal smears. Ovarian tissues were histologically evaluated, the number of primordial, mature, and atretic follicles was calculated, and the apoptotic rate of granulosa cells. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂) levels were determined by ELISA assays. Protein levels of Forkhead Box O1 (FOXO1), KLOTHO, Bcl-2, and Bax were investigated in ovarian tissues of DOR rats. The binding between FOXO1 and KLOTHO was verified by ChIP assay. High-dose administration of RD into DOR rats improved their estrus cycles, increased ovarian index, enhanced the number of primordial and mature follicles, reduced the number of atretic follicle number, and ovarian granulosa cell apoptosis in addition to inhibiting FSH and LH levels and upregulating E₂ expression. FOXO1 and KLOTHO were significantly suppressed in DOR rats. FOXO1 knockdown partially suppressed the protective effects of RD on DOR rats, and KLOTHO overexpression could restore RD-induced blockade of DOR development despite knocking down FOXO1. FOXO1 antibody enriched KLOTHO promoter, and the binding between them was reduced in DOR group compared to that in sham group. RD improved ovarian functions in DOR rats and diminished granulosa cell apoptosis via the FOXO1/KLOTHO axis.

• 오토저널
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• 제14권3호
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• pp.90-101
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• 1992

An experimental study was carried out to investigate the characteristics of cyclic variability of combustion in a single cylinder spark ignition engine. Cylinder pressure of 240 consecutive cycles were measured for various engine operating conditions. From these data, a thermody-n amic analysis was performed for the typical cases in order to identify the cause and effect re -lation of the cyclic variation. In determining the number of cycles required for estimating the coefficient of variation of IMEP and so on, the oprating conditions must be cosidered to fit the objective of the analysis. It is thought that the variation in early flame stage is amplified through the flame propagation and results in the phase change between pressure and volume, which can be the major reason of cyclic variation of IMEP in case of lean operation.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.957-960
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• 2006

In order to predict the accumulated damages by cyclic freeze-thaw, a regression analysis by the Response Surface Method (RSM) is used. RSM has merits when the other probabilistic simulation techniques can not guarantee the convergence of probability of occurrence or when the others can not differentiate the derivative terms of limit state functions, which are composed of random design variables in the model of complex system or the system having higher reliability. For composing limit state function, the important parameters for cyclic freeze-thaw-deterioration of concrete structures, such as water to cement ratio, entrained air pores, and the number of cycles of freezing and thawing, are used as input parameters of RSM. The predicted results of relative dynamic modulus and residual strains after 300 cycles of freeze-thaw for specimens show very good agreements with the experimental results. The RSM result can be used to predict the probability of occurrence for designer specified critical values. Therefore, it is possible to evaluate the life cycle management of concrete structures considering the accumulated damages by the cyclic freeze-thaw by the use of proposed prediction method.

• 한국세라믹학회지
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• 제55권5호
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• pp.452-460
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• 2018

This study investigate changes in mechanical behaviors such as indentation load-displacement and hardness of thermal barrier coatings (TBCs) using cycling of thermal shock test. Relatively dense and porous TBCs on nickel-based bondcoat/super alloy are prepared using different starting granules, 204C-NS and 204NS commercial powers, and the effect of double layers of 204C-NS on 204NS and 204NS on 204C-NS are investigated. The highest temperature applied during thermal shock test is $1100^{\circ}C$ and the maximum number of cycles is 1,200. The results indicate that bilayered TBC showed a relatively mechanically resistant property during thermal shock cycles and that the mechanical behavior is influenced by the microstructure of TBCs by exposure to high temperature during tests or different starting granules.