• 한국가축번식학회지
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• 제8권2호
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• pp.87-91
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• 1984

This study was conducted to determine the optimum time and the insemination site of frozen in Cheju native cows, and 660 cows first service inseminated with rectovaginal methods by 3 skillful technicians as 3 districts near Cheju City and Sogwipo City areas obtained the following results. Optimum time for insemination was 16-20 hours after the onset of estrus and 80.6% of 67 conceived to first insemination. In the rectovaginal technique used widely at present conception rate for the palpation of ovaries showed 6.6% (index) higher than that of non-palpation. Conception rate of the insemination site; the intra-uterine horn, intra-uterus, just inside the cervix and depositing in mid-cervix were 62.5, 78.4, 74.6, and 80.9% respectively, however, there was no difference in conception rate between cervical and uterine deposition of forzon semen except for the intra-uterine horn.

• Journal of Chest Surgery
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• 제27권9호
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• pp.723-731
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• 1994

We have modified the isolated perfused working rabbit lung model [IPWL] by perfusing the isolated lung with a hollow fiber membrane deoxygenator.For assessment the stored lung was ventilated with FIO2 0.4 and perfused with 37$^{\circ}$C deoxygenated circulating blood at a rate 5ml/kg/min for several hours until lung failure.We chose to compare our developing solution which contained low potassium and pentastarch with the modified Euro-Collins solution .Experiments were divided into four groups[n=6] based on the type of flushing preservation solution and preservation time.The flushed lungs were then preserved into same solution at 8~10$^{\circ}$C with 100% O2 inflated condition for 1 or 20 hours.These following results were obtained.The IPWL model requires only one animal per experiment and allows for the continuous assessment of aerodynamic performance. This should therefore be used as screening test in lung preservation.One hour preservation groups, there were no significant difference in recovery rates of PaO2, PAP and Paw. Survival time in the one hour preservation groups were very significant long in the Group II[LPPS, p<0.01]. Twenty hours preservation groups, there were no significant difference in the recovery rates of PAP and Paw between Group III[m-ECS] and Group IV[NS], but PaO2 was significantly worse at onset of reperfusion in Group III when compared with Group IV [p<0.05]. And also survival time in the 20 hours preservation groups were significant long in the Group IV [p<0.05].

• Journal of Animal Science and Technology
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• 제56권3호
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• pp.8.1-8.6
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• 2014

Background: Artificial insemination (AI) can serve as a powerful tool to the sheep owners for making rapid genetic progress of their flock. The AI in sheep is mostly performed using fresh semen with two reasons i) lambing rate following trans-cervical AI with frozen semen is limited by the inability of frozen-thawed sperm to transit the cervix and ii) the need of circumventing the cervical barrier through laparoscope aided intrauterine AI. Therefore, AI with frozen-thawed semen is not as widespread in sheep as it is in other domestic species. However, to get maximum benefits through the use of AI, frozen-thawed semen is a prerequisite because instead of high fertility, the short shelf life of fresh semen coupled with a limitation on the number of insemination doses achievable per unit time restricts the widespread use of individual sires. Therefore, in order to enhance lambing rate, a total of 240 trans-cervical artificial inseminations with frozen-thawed semen were performed in Bharat Merino ewes during autumn season either once in the evening (G-I, 10 h after onset of estrus, n = 100) or twice (G-II, 14 h and 22 h after onset of estrus, n = 140) i.e. once in the morning and again in the evening. Results: The pregnancy rate (proportion of pregnant ewes confirmed by ultrasonography at day 40) and lambing rate (proportion of ewes lambed) were higher in G-II as compared to G-I (26.4 vs 20% and 19.3 vs 10%, respectively). The difference in lambing rates was statistically (P < 0.05) significant. The depth of insemination within cervico-uterine tract had no significant effect on pregnancy and lambing rates. Conclusions: The results indicate that lambing rate in sheep following TCAI with frozen-thawed semen was significantly influenced by time of inseminations. Two inseminations after 14 and 22 h of onset of estrus enhanced the lambing rates of Bharat Merino sheep as compare to single insemination after 10 h of onset of estrus. The TCAI technique with frozen-thawed ram semen is promising and may serve as a valuable tool for genetic improvement of sheep breeds. Research efforts are going on worldwide to overcome the poor fertility following TCAI with frozen-thawed semen.

• 대한치과마취과학회지
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• 제4권2호
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• pp.84-89
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• 2004

Background: Many studies on efficacy of preemptive analgesia have been processed in different ways. But the value of preemptive analgesia is still controversial. The goal of this study was to compare analgesic effect of an NSAID according to three different administration times for oral surgical pain. Patients and Methods: Using a randomized, parallel-group, single-center, and active-controlled test design, this study was conducted to healthy 80 patients undergoing a surgical removal of an impacted mandibular third molar requiring bone removal. The oral NSAID was first administered 1 hour preoperatively, or 1 hour postoperatively, or no scheduled administration in pre or postsurgery. Whenever patients felt at least moderate pain (score ${\ge}$ 5 on a 10-point scale) after surgery, they were instructed to take the same drug. Pain intensities and times to the first and second onset of postoperative pain from end of surgery were assessed for 24 hours. Results: Of the enrolled eighty subjects in this study, 25 patients were assigned to preemptive, 26 to post-treatment and 29 to no treatment group. The demographic distribution and duration of surgery in the three groups were statistically similar. The mean time to first onset of postoperative pain was significantly prolonged in post-treatment group (277.2 minutes, p < 0.05) compared to preemptive (158.4 minutes) and no treatment group (196.5 minutes). The mean time to second onset of postoperative pain was not significantly different among the three groups. No significant statistical difference was found among the mean pain intensities at the first and second onset of postoperative pain in the three groups. Conclusions: In this small selected group of subjects and limited study design, the analgesic effects of NSAID administered preoperatively were no longer effective for postoperative pain. The results in this population imply that scheduled postoperative analgesics before pain development are adequate for postoperative analgesia without preoperative administration.

• 말소리와 음성과학
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• 제2권3호
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• pp.3-10
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• 2010

The proposal that a sound change is occurring in Korean stops was evidenced in this study through identification experiments on Korean stops. Perceptual weight of acoustic correlates to Korean stop manner contrast [VOT (Voice Onset Time), H1-H2 (amplitude difference between the first and second harmonics), and F0 (Fundamental frequency)] was examined with re-synthesized /$t^ha$/, /ta/, and /$t^*a$/ syllables for younger and older Seoul speakers of Korean. For the identification of the aspirated and lenis stops, F0 cue weight relative to VOT was greater for the younger listeners than the older listeners. For H1-H2 cue weight, the two listener groups were more or less the same. These findings were parallel to the production differences found in the earlier work of the author. Combined with production differences, these perception differences between younger and older generations of Seoul speakers suggested that there are generational differences in the phonetic targets of Korean aspirated and lenis stops and such differences are realized in the perception of the stops.

• 말소리와 음성과학
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• 제8권1호
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• pp.25-36
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• 2016

Previous studies showed that the voice onset time (VOT) of aspirated and lenis stops has been merged, and post-stop fundamental frequency (F0) has emerged as a primary cue to distinguish the two stops in the younger generation and female speech. The purpose of this study is to demonstrate that VOT merger in aspirated and lenis stops occurs after an F0 difference between the two stops becomes stabilized. In other words, unless post-stop F0, which is a redundant feature, is fully developed, it is hard for VOT merger to happen. Females have got a stable F0 difference in stops earlier than males. Therefore, VOT merger could happen, and as a result, females could take the lead in changing from VOT to F0 in initial stops. This study also shows that speakers who acquired F0 as a primary cue use F0 to the full to distinguish lenis stops from two other stops (aspirated and fortis).

• 대한치과교정학회지
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• 제28권3호
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• pp.409-417
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• 1998

경희의료원 치과병원 교정과에 내원한 부정교합자 중 전신 건강 상태가 양호한 123명의 좌측 수완부골 방사선 사진을 이용하여, 초경과 골격성숙도간의 상관관계를 연구한 결과 다음과 같은 결론을 얻었다. 1. 초경 발현 연령은 평균 12.31세, 최소 9.6세, 최고 15.6세로 개체간 변이가 심하였다. 2. 초경시 골성숙 상태는 SMI 7,8단계($73\%$), 즉 제5중절골의 골단이 골간을 둘러싸거나 제3말절골의 골간과 골단이 융합되는 단계이며, 초경시의 골격성숙도는 초경 발현 연령에 관계없이 일정하였다. 3. 골성숙단계에 따른 초경 후 경과기간간에는 유의한 차이가 있었다. 4. 요골의 융합은 초경 후 평균 1년 8개월이 지나면 시작되었다. 5.초경 발현 연령에 따른 성장 속도의 비교에서, 만기성숙아(초경을 늦게 경험하는 여아)는 초경 후 14개월이 지나면 요골의 융합이 시작되었고, 조기성숙아(초경을 일찍 경험하는 여아)는 초경후 22개월, 평균성숙아는 초경후 20개월이 지나면 요골의 융합이 시작되었다.

• 말소리와 음성과학
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• 제5권4호
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• pp.81-90
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• 2013

This study explored how Korean L2 learners of English utilize multiple acoustic cues (VOT and F0) in perceiving and producing the English alveolar stop with a voicing contrast. Thirty-four 18-year-old high-school students participated in the study. Their English proficiency level was classified as either 'high' (HEP) or 'low' (LEP) according to high-school English level standardization. Thirty different synthesized syllables were presented in audio stimuli by combining a 6-step VOTs and a 5-step F0s. The listeners judged how close the audio stimulus was to /t/ or /d/ in L2 using a visual analogue scale. The L2 /d/ and /t/ productions collected from the 22 learners (12 HEP, 10 LEP) were acoustically analyzed by measuring VOT and F0 at the vowel onset. Results showed that LEP listeners attended to the F0 in the stimuli more sensitively than HEP listeners, suggesting that HEP listeners could inhibit less important acoustic dimensions better than LEP listeners in their L2 perception. The L2 production patterns also exhibited a group-difference between HEP and LEP in that HEP speakers utilized their VOT dimension (primary cue in L2) more effectively than LEP speakers. Taken together, the study showed that the relative cue-weighting strategies in L2 perception and production are closely related to the learner's L2 proficiency level in that more proficient learners had a better control of inhibiting and enhancing the relevant acoustic parameters.

• Korean Chemical Engineering Research
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• 제59권1호
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• pp.138-151
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• 2021

The effect of a reactant ratio on the growth of a buoyancy-driven instability in an irreversible A+B→C reaction system is analyzed theoretically and numerically. Taking a non-stoichiometric reactant ratio into account, new linear stability equations are derived without the quasi-steady state assumption (QSSA) and solved analytically. It is found that the main parameters to explain the present system are the Damköhler number, the dimensionless density difference of chemical species and the ratio of reactants. The present initial grow rate analysis without QSSA shows that the system is initially unconditionally stable regardless of the parameter values; however, the previous initial growth rate analysis based on the QSSA predicted the system is unstable if the system is physically unstable. For time evolving cases, the present growth rates obtained from the spectral analysis and pseudo-spectral method support each other, but quite differently from that obtained under the conventional QSSA. Adopting the result of the linear stability analysis as an initial condition, fully nonlinear direct numerical simulations are conducted. Both the linear analysis and the nonlinear simulation show that the reactant ratio plays an important role in the onset and the growth of the instability motion.

• 한국산학기술학회논문지
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• 제13권6호
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• pp.2632-2640
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• 2012

본 연구의 목적은 지연성근통증에 대한 내측 비복근 초음파 영상의 측정도구로서의 가능성에 대해 알아보고자 함에 있다. 본 연구는 2011년 4월 21일부터 4월30일까지 실시되었다. 평소 규칙적인 운동을 하지 않으며, 최근 외상의 경험, 근골격계 질환, 심혈관계 질환이 없고 약물을 복용하지 않는 35명의 건강한 성인이 참여하였다. 대상자들은 5시간의 등반을 통해 지연성근통증을 유발하였으며, 지연성근통증 전과 지연성근통증 후 24, 48, 72시에 통증(visual analogue scale :VAS), 혈중 크레아틴 키나아제(creatine kinase: CK) 활성도, 족저 굴곡근의 최대근수축력(maximal voluntary isometric contraction: MVlC)을 측정하였고, 이 측정값과 초음파로 측정한 내측 비복근의 우상각을 비교하였다. 연구의 결과는 다음과 같다. 통증지표, 혈중 크레아틴 키나아제 활성도, 족저 굴곡근 최대등척성근수축력에 측정시기에 따른 유의한 차이가 발생하였으며(p<0.05), 내측 비복근 우상각에서도 측정시기에 따른 유의한 차이가 발생하였다(p<0.05). 또한 변수 간 측정시기에 따른 변화의 흐름이 일치하는 것을 확인하였다. 본 연구를 통해 초음파 검사를 통한 내측 비복근 우상각의 시간경과에 따른 변화 측정이 지연성근통증을 감지하는 새로운 측정방법으로 사용될 수 있을 것이라 생각한다.