• 대한치과교정학회지
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• 제27권3호
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• pp.481-492
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• 1997

하악골의 성장은 골격적 요인이 동반된 III급 부정교합자의 치료의 결과, 예후에 중대한 영향을 미칠 수 있으며, 특히 성장기 환자의 경우 성장의 조절을 통하여 효과적인 치료를 기할 수 있으므로 개개인의 성장양상을 평가하기 위한 여러 방법들에 관하여 선학들의 많은 연구가 있어왔다. 본 연구에서는 하악골 성장예측의 지표로 경추골 성숙도를 이용한 골령평가법이 유용한 지를 알아보기 위해 1972년 Lamparski 에 의해 제안된 표준 경추골 성숙단계를 이용하여 정상교합자 남자 18명, 여자 14명의 8.5세에서 18.5세까지 매 2년 간격으로 촬영한 측모두부방사선 규격사진 192매에 나타난 경추골 성숙도와 하악골 및 신장의 성장간의 관련성을 분석하여 다음과 같은 결론을 얻었다. 1. 8.5세에서 14.5세까지는 동일한 연령군에서 여자가 남자보다 높은 경추골 성숙단계를 나타내었다. 2. 동일한 경추골 성숙단계에 도달하는 평균연령은 일반적으로 여자가 남자보다 이른 나이를 보였다. 3. 일반적으로 경추골 성숙단계 3-4단계간에 하악골 및 신장의 최대성장이 일어났다. 4. 경추골 성숙도와 하악골의 성장간에는 일정한 관련성이 있어 경추골 성숙도를 하악골 성장예측의 지표로 사용하는 것이 가능할 것으로 생각된다.

• 한국수정란이식학회지
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• 제28권3호
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• pp.169-175
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• 2013

Recently, the transgenic animal production technique is very important for the production of bio-parmaceutical as animal bio-reactor system. However, the absence of survival evaluation in vitro produced transgenic embryos has been a problem of the low productivity of transgenic animal because of absent of pre-estimate of pregnancy after transgenic embryos transferred into recipient. Therefore, this study is conducted to improve efficiency of transgenic cattle production by improving the non-surgical embryo transfer (ET) method. Transgenic bovine embryos were produced by injection of feline immunodeficiency virus enhanced green fluorescent protein (FIV-EGFP) lentiviral vector into perivitelline space of in vitro matured MII stage oocytes, and then in vitro fertilization (IVF) was occured. Normal IVF and EGFP expressing blastocysts were transferred into recipients. Results indicated that 2 expanded blastocysts (34.7%) transferred group showed significantly (P<0.05) higher pregnancy rate than 1 expanded blastocyst (26.8%) transferred group. In case of parity of recipient, ET to heifer (34.9%) showed significantly (P<0.05) higher pregnancy rate than ET to multiparous recipient (21.2%). However, there are no significant differences of pregnancy rate between natural induced estrus and artificial induced estrus groups. Significantly (P<0.05) higher pregnancy rate was obtained from recipient group which have normal corpus luteum with crown group (34.8%) than normal corpus luteum without crown (13.6%). Additionally, treatment of $100{\mu}g$ Gn-RH injection to recipient group (38.6%) 1 day before ET significantly (P<0.05) increase pregnancy rate than non- Gn-RH injection to recipient group (38.6%). We also transferred 2 EGFP expressing expanded blastocysts to each 19 recipients, 7 recipients were pregnant and finally 5 EGFP transgenic cattle were produced under described ET condition. Therefore, our result suggested that transfer of 2 good-quality expanded blastocysts to $100{\mu}g$ of Gn-RH injected recipient which have normal corpus luteum with crown is feasible to produce transgenic cattle.

• 한국운동역학회지
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• 제25권3호
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• pp.323-333
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• 2015

Objective : The purpose of this study was to investigate the changes of gait patterns and muscle activations with increased loads during stair walking. Also, it can be used as descriptive data about continuous stair walking in a real life setting. Method : Twelve sedentary young male adults(Age: $27.0{\pm}1.8yrs$, Weight: $65.8{\pm}9.9kg$) without any lower extremity injuries participated in this study. Participants performed stair walking up 7 floors and their ascending and descending motion on each floor was analyzed. A wireless electromyography(EMG) were attached on the Rectus Femoris(RF), Biceps Femoris(BF), Gastrocnemius(GN), Tibialis Anterior(TA) muscle to calculate integrated EMG(iEMG), median frequency(MDF) and co-contraction index(CI). Chest and left heel accelerometer signal were recorded by wireless accelerometer and those were used to calculate approximate entropy(ApEn) for analyzing gait pattern. All analyses were performed with SPSS 21.0 and for repeated measured ANOVA and Post-hoc was LSD. Results : During ascending stairs, there were a statistically significant difference in Walking time between 1-2nd and other floors(p=.000), GN iEMG between 2-3th and 6-7th(p=.043) floor, TA MDF between 1-2nd and 5-6th(p=.030), 6-7th(p=.015) floor and TA/GN CI between 2-3th and 6-7th(p=.038) floor and ApEn between 1-2nd and 6-7th(x: p=.003, y: p=.005, z: p=.006) floor. During descending stairs, there were a statistically significant difference in TA iEMG between the 6-5th and 3-2nd(p=.026) floor, and for the ApEn between the 1-2nd and 6-7th(x: p=.037, y: p=.000, z: p=.000) floor. Conclusion : Subjects showed more regular pattern and muscle activation response caused by regularity during ascending stairs. Regularity during the first part of stair-descending could be a sign of adaptation; however, complexity during the second part could be a strategy to decrease the impact.

• 한국자동차공학회논문집
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• 제5권6호
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• pp.13-27
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• 1997

In the modern design technology, a component should be designed to fit into the overall system performance. A design methodology is developed to expedite the mechan- ical design of complex mechanical systems, The relation between the system design and component design is defined by a top-down approach and the results from the system design are utilized in the component design process. As a design example, an automobile exhaust system is selected for the system design and a bellows is chosen for a component design. Design methodology based on the top-down approach consists of five steps; (1) Analysis of service load, (2) Development of a lumped parameter, (3) Completion of the system design, (4) Selection of the component topology, (5) Completion of the component design, A method using a equivalent matrix is developed in order to determine unknown external forces in linear structural analyses. The bellows is also analyzed by the finite element method using a conical frustum shell element. Various experiments are performed to verify the developed theories. The top-down desi- gn approach is demonstrated by a design case using structural and shape optimization technology. Since the method is relatively simple and easy compared to other methods, it can be applied to the general design where system and component designs are involves simultaneously.

• 한국전기전자재료학회논문지
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• 제25권6호
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• pp.409-413
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• 2012

In this study, a substrate-bias assisted 2-step pulse programming method is proposed for realizing 4-bit/1-cell operation of the SONOS memory. The programming voltage and time are considerably reduced by this programming method than a gate-bias assisted 2-step pulse programming method and CHEI method. It is confirmed that the difference of 4-states in the threshold voltage is maintained to more than 0.5 V at least for 10-year for the multi-level characteristics.

• 한국발생생물학회지:발생과생식
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• 제21권3호
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• pp.307-315
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• 2017

Surgical castration (also known as orchidectomy, ORX) has been frequently performed to avoid uncontrolled breeding. However, it has some serious disadvantages. Several laboratories have developed chemical castration methods, using bilateral intratesticular injection (BITI) of simple chemical solutions. The present study was undertaken to compare the effects of ORX and of hypertonic saline BITI on the androgen-sensitive tissues such as pituitary and hypothalamus. Serum testosterone (T) levels of ORX animals and hypertonic saline BITI animals (SAL) after 4 weeks of the manipulations exhibited significantly drops as compared with the levels of intact animals ( $Intact:ORX:SAL=7.74{\pm}1.31:1.34{\pm}0.19:1.28{\pm}0.18ng/ml$, p<0.001). Both ORX and BITI method induced similar stimulatory effects on the pituitary gonadotropin subunits and hypothalamic KiSS-1 gene expressions. In contrast, the effects of ORX and hypertonic saline BITI on hypothalamic GnRH gene expression were different from these gene expressions, shown an inverse relationship between the two groups ($Intact:ORX:SAL=1:0.45{\pm}0.06:1:2.07{\pm}0.41:1.51{\pm}0.37AU$; ORX, p<0.001; SAL, p<0.05). In conclusion, we provided evidence that hypertonic saline BITI method has equivalent efficacy of T depletion to surgical castration in rats. The present study suggests the hypertonic saline BITI could be a promising substitute to conventional surgical castration.

• 복합신소재구조학회 논문집
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• 제6권2호
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• pp.1-7
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• 2015

As energy consumption of building and the reduction of carbon dioxide emissions have been emphasized, phase change materials(PCM) have been introduced as building materials due to its high heat storage performance. Using shape-stabilizing technique, octadecane/xGnP shape-stabilized PCM(SSPCM) can prevent leakage and improve heat storage performance. The objectives of this study are to propose mix design method of concrete mixed with SSPCM and to evaluate mechanical behaviors of the concrete mixed with SSPCM manufactured according to the proposed mix design. Based on the previously reported material test result, the existing mix design of plain concrete(Concrete standard specification, 2009) is modified to consider reduction of strength in concrete due to the addition of SSPCM. To verify the proposed mix design, specimens are fabricated according to the proposed mix design and axial strength tests and three-point loading tests are performed. Test results show that compressive strengths of the tested specimens reach the designed strength even when two different mix ratios of SSPCM are used. From three-point loading tests, flexural stresses decrease as mix ratio of SSPCM increases.

• Structural Engineering and Mechanics
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• 제81권4호
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• pp.503-511
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• 2022

In this article, we have examined the effect of fractional order parameter in a two-dimensional orthotropic magneto-thermoelastic solid in generalized thermoelasticity without energy dissipation with fractional order heat transfer in the context of hall current, rotation and two-temperature due to normal force. Laplace and Fourier transform techniques are used to obtain the solution of the problem. The expressions for displacement components, stress components, current density components and conductive temperature are obtained in transformed domain and then in physical domain by using numerical inversion method. The effect of fractional parameter on all the components has been depicted through graphs. Some special cases are also discussed in the present investigation.

• Clinical and Experimental Reproductive Medicine
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• 제23권1호
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• pp.51-59
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• 1996

체외수정 시술을 위해 중앙대학교부속병원 산부인과학 교실 불임크리닉을 방문한 환자중 1993년 3월부터 1994년 8월까지 난관폐쇄로 인하여 불임이 된 환자 113명(119주기)을 대상으로 GnRH-a 병합요법 중 Short protocol 방법으로 과배란시 임신된 45명(47주기)과 임신이 되지 않은 68명(72주기)에서 hCG 투여 당일 혈청내 E2 및 P4 수치를 측정하여 임신의 결과를 비교하였다. 1. 환자의 평균 연령 및 불임기간은 임신군에서 $33.2{\pm}14.8$세 및 $4.2{\pm}3.4$년이었으며 비 임신군에서는 $34.5{\pm}21.7$세 및 $3.9{\pm}2.8$년으로 연령 및 불임기간의 차이는 없었다. 2. hGC 투여 당일 측정한 혈중 E2치는 임신군에서는 $1643{\pm}987.9$ pg/ml, 비임신군에서는 $1367{\pm}875.8$ pg/ml로 임신군에서 유의하게 높았다(P<0.01). 또한 혈중 LH치는 인신군 에서는 $16.7{\pm}10.4$ ng/ml, 비임신군에서는 $18.3{\pm}8.3$ ng/ml로 임신군에서 유의하게 낮았다 (P<0.01). 혈중 P4치는 임신군에서는 $1.0{\pm}0.7$ ng/ml이었고 비임신군에 서는 $2.1{\pm}1.4$ ng/ml로서 임신군에서 유의하게 낮았다(P<0.001). 3. hCG 투여당일 E2/P4 비는 임신군에서 $1865.6{\pm}318.1$, 비임신군에서는 $1324{\pm}377.7$ 로서 유의한 차이가 있었다(P<0.01)(Table 3). 4. 주기당 수정율은 임신군에서 $61.3{\pm}21.3%$, 비임신군에서는 $41.1{\pm}20.3%$로 임신군에서 의미있게 높았고(P<0.01) 이식된 배아의 수는 임신군 47주기에서 $4.2{\pm}2.2$개, 비임신군 72주기에서는 $2.3{\pm}1.2$개로 두 군간의 차이는 없었다(Table 4). 이상에서 임신이 된 군은 임신이 안된 군보다 혈중 progesterone 치가 의미있게 낮았고 혈중 estradiol 치는 의미있게 높았음을 알 수 있었다. 혈중 progesterone 및 estradiol치는 과배란 유도 후 체외수정시술에 있어서 수정율 및 임신율에 영향을 줄 수 있다고 생각되며 이는 체외수정시술시 과배란후 임신의 예후판정에 효용성이 있을것으로 사료된다.

• Clinical and Experimental Reproductive Medicine
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• 제37권1호
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• pp.41-48
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• 2010

목 적: 체외수정시술 시 황체기 보강은 근주, 경질, 경구 등의 다양한 방법으로 이루어지고 있는데, 경구 투여법은 환자의 순응도가 높고 비교적 안전한 방법이다. 본 연구에서는 황체기 보강을 근주로 시작하여 경구 투여로 전환하는 방법의 효용성과 전환 시기에 따른 결과를 비교 분석하고자 하였다. 연구방법: 2003년 9월부터 2009년 6월까지 분당서울대학교병원에서 체외수정시술을 시행받은 환자에서 배아 이식 후 태아 심박동까지 확인된 76주기를 대상으로 하였다. 과배란유도는 GnRH agonist long protocol (n=7) 또는 GnRH antagonist protocol (n=66)을 이용하였으며 3주기에서는 냉동배아 이식을 시행하였다. 황체기 보강을 위하여 난자 채취일부터 매일 progest in oil 50 mg을 근주하였고, 태아 심박동이 확인된 후 임신 6~7주 (n=17) 또는 8주 이후 (n=59)에 micronized progesterone (Utrogestan, Laboratoires Besins International, France) 300 mg을 매일 경구로 투여하였다. 결 과: 대상군 전체의 유산율은 3.9% (3/76)이었으며, 경구 투여 전환시의 임신 주수는 평균 8주 4일 (난자 채취일로부터 $46{\pm}5.8$일)이었다. 황체기 보강을 임신 6~7주 사이에 경구 투여로 전환한 17주기 중에서 1례의 자연유산이 확인되었으며 유산 시 주수는 9주 4일이었다. 8주 이후에 경구 투여로 전환한 59주기 중에서는 2례의 자연유산이 확인되었으며 (11주 3일, 11주 4일), 두 군의 자연유산율은 각각 5.6%와 3.4%로 두 군 간에 통계적으로 유의한 차이는 없었다 (p=0.678). 결 론: 체외수정시술 후 황체기 보강을 시행하는 경우 태아 심박동이 확인된 이후에 근주 투여를 경구 투여로 전환하는 방법은 비교적 낮은 유산율을 보임을 확인하였으며, 특히 8주 이전에 전환하는 것도 유용한 방법이라 사료된다.