• 한국추진공학회지
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• 제20권3호
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• pp.32-36
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• 2016

고체로켓추진기관 연소관 내열고무의 열반응 특성을 평가하기 위한 모사시험장치를 개발하였다. 시험장치는 연소실 압력 2,500 psi, 연소시간 100 s까지 시험할 수 있으며, 여러 시편을 동시에 상대 비교 할 수 있다. 시편 부는 사각 패널로 되어 있으며, 마주보는 두 면에서는 연소시간 동안 시편 내부의 온도 변화를 측정할 수 있다. 시험장치의 안전성을 확인하기 위하여 연소실 유효평균압력 1,000 psi, 유효연소시간 10 s 시험을 수행하였으며, 내열고무의 열특성 분석에 필요한 기본 데이터들, 즉 연소실의 압력-시간 선도, 재료 내부에서의 온도-시간 선도, 재료의 열파괴 두께를 획득하였다.

• 한국식품과학회지
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• 제33권4호
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• pp.486-491
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• 2001

국내외에서 분양 받고 국내식육에서 분리된 총 100균주의 Y. enterocolitica에 대한 병원성여부를 HEp-2세포 침투성 시험법을 기준으로 하고 여러 가지 병원성 확인 방법을 비교하였다. 혈청형만으로 병원성을 판단하기에는 충분하지 않았고 이외의 방법 즉, esculin과 salicin시험, pyrazinamidase 시험, biotype 등의 생화학적 특성에 바탕을 둔 실험 단독으로 병원성을 판단하기에는 완전하지 않았다. D-xylose 발효실험, CRMOX agar 시험과 자동응고반응(Autoagglutination)들은 병원성확인에 보조적인 역할만을 할 수 있었다. HEp-2 세포 침투성 시험법은 시간과 노력이 많이 소요되므로 이 방법을 대치할 수 있는 간단하고 신속, 정확하게 Y. enterocolitica 병원성을 확인할 수 있는 방법은 esculin시험에서 음성반응을 보이는 것만 PCR시험을 행하여 판별하는 것이라고 사려된다.

• 대한수학교육학회지:수학교육학연구
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• 제12권3호
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• pp.371-388
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• 2002

The purpose of this study is to analyze the effects of interaction based on contingent regulation between teacher and underachiever in elementary mathematics. For this purpose, research questions are established as follows; (1) Is there any difference between contingent regulation and natural regulation in mathematics achievement\ulcorner (2) Is there any difference between contingent regulation and natural regulation in affectionate perspective\ulcorner (3) Is there any difference between contingent regulation and natural regulation in adult regulation\ulcorner Two classes of fifth grade Children(10 children) were sampled from an elementary school in city of Daegu. One of them was assigned to the contingent regulation group and the other to natural regulation group. An experiment was conducted for 7 weeks. Two kinds of test instruments were used : pre-test and post-test. The pre-test scores guaranteed that both groups were homogeneous. Post-test was used to identify two effects(research questions (1) & (2)) and the post-test scores were analyzed by t-test. The results were as follows. (1) There was significant difference between contingent regulation and natural regulation in mathematics achievement. This means that experiment group was higher than control group and the interaction effect of contingent regulation was higher in post-test. The self-control indicated in experiment group. (2) There was slightly significant difference between contingent regulation and natural regulation in affectionate perspective. This means that experiment group turned to slightly positioner in post-test. (3) There was significant difference between contingent regulation and natural regulation in adult regulation. In other words, level of contingent regulation changed depending on underachievers' ability but level of natural regulation didn't change. Therefore, I suggest that contingent regulation based on Vygotsky theory would provide effective mathematics education for underachievers in elementary mathematics.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.1160-1164
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• 2017

본 연구에서는 루츠 펌프와 스크류 펌프를 이용한 진공 펌프 시스템을 이용해, 1 kg/s의 공기가 공급되는 시험장치에서 챔버 내의 압력을 2500 Pa로 유지할 수 있는 고도모의 시험장치를 설계하였다. 설계를 위해, 저유량의 공기 공급 조건에서, 소정의 펌프 조합을 이용해 실험을 수행하였다. 이를 통해, 1 kg/s급의 유량이 공급되는 시험장치를 위해서는 11대의 루츠 펌프와 33대의 스크류 펌프가 필요하다는 것을 확인할 수 있었다. 실험 결과를 이론 예측 결과와 비교하였다. 하지만, 이론적으로 예측한 흡입 유량은 실험 결과보다 20 %에 가깝게 많게 나왔다. 이는 조합 실험시, 루츠 펌프 전후단에 걸리는 차압이 높아서 발생한 것으로 여겨진다. 따라서 앞에서 제시한 것보다 더 많은 스크류 펌프를 설치할 경우, 보다 높은 진공도를가지는 시스템의 구축이 가능해질 것으로 판단된다.

• 한국항공우주학회지
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• 제37권8호
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• pp.780-788
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• 2009

복합재 날개 구조물에 대한 구조 건전성 및 손상을 평가하기 위하여 정적 구조강도시험에 음향방출(AE)법이 응용되었다. 시험중 스트레인과 변위측정기법을 통하여 정적구조강도를 확인하였고, 음향방출요소 분석과 위치표정기법을 통하여 구조물의 내부 손상을 평가하고 손상위치를 찾을 수 있었다. 시험은 설계제한하중시험, 2차에 걸친 설계극한 하중시험, 파단시험이 수행되었다. 주요한 AE신호는 front lug근처의 표면에 부착된 센서에 의하여 감지되었다. 특히 1차 설계극한하중시험에서 스트레인 및 변위결과는 내부 손상을 보이지 않았으나 AE신호는 내부 손상이 이미 형성된 현상을 나타내었다. 파단시험에서는 AE활성도가 매우 활발하였고, 스트레인 및 변위의 결과는 심한 손상에 의하여 하중경로가 바뀌는 경향을 나타내었다. 음향방출법을 적용하여 정적 구조시험이 진행되는 동안 내부손상이 발생되는 하중과 위치를 정확하게 평가할 수 있었다. 본 연구로부터 음향방출법은 정적 구조강도시험에 있어 내부 손상을 평가하는데 유용한 기법임이 확인되었다.

• 한국항공우주학회지
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• 제50권10호
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• pp.739-745
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• 2022

전투기의 여러 가지 환경 요구도 중 폭발성 대기는 항공기 체계와 승무원의 안전을 위해 군수품의 점화 여부를 확인하는 시험이다. 시험은 한국생산기술연구원(KITECH)에서 보유하고 있는 폭발성 대기 시험장비를 활용하였고, 보수적으로 시험을 수행하기 위해 일반 연료보다 점화 특성이 민감한 n-hexane을 사용하였다. 미 군용 환경시험 규격서인 MIL-STD-810G w/Change 1, Method 511.6, Procedure I을 바탕으로 적용 범위와 테일러링(Tailoring) 가이드, 세부 시험절차를 확인하고 전투기의 각 계통에 대한 본 시험의 필요성을 고찰한다. 본 연구를 통해 전투기에 장착되는 구성품에 대한 폭발성 대기 시험 결과를 분석하고, 도출한 주안점을 공유하여 올바른 테일러링 방안을 제시한다.

• Archives of Pharmacal Research
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• 제29권12호
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• pp.1080-1085
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• 2006

A series of 8-alkoxy-4,5-dihydro-[1,2,4]triazole[4,3-a]quinoline-1-one derivatives were synthesized using 7-hydroxy-3,4-dihydro-2(1H)-quinolone as the starting material. Their anticonvulsant activities were evaluated by the maximal electroshock test (MES) and the subcutaneous pentylenetetrazole test (sc-PTZ), and their neurotoxicities were measured by the rotarod neurotoxicity test (Tox). The tests demonstrated that 8-hexyloxy-4,5-dihydro-[1.2.4]triazole[4.3-a]quinoline-1-one (4e) and 8-heptyloxy-4,5-dihydro-[1,2,4]triazole[4, 3-a]quinoline-1-one (4f) were the most potent anticonvulsants, with 4e having $ED_{50}$ values of 17.17 mg/kg and 24.55 mg/kg and protective index ($PI=TD_{50}/ED_{50}$) values of 41.9 and 29.3 in the MES and sc-PTZ tests, respectively, and 4f having $ED_{50}$ values of 19.7 mg/kg and 21.2 mg/kg and PI values of 36.5 and 33.9 in the MES and sc-PTZ tests, respectively. The PI values of 4e and 4f were many fold better than that of the marketed drugs phenytoin, carbamazepine, phenobarbital and valproate, which have PI values in the range of 1.6-8.1 in the MES test and <0.22-5.2 in the sc-PTZ test. Structure-activity relationships were also discussed.

• 대한관절경학회지
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• 제17권1호
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• pp.18-23
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• 2013

목적: Outside-in 술기를 이용한 해부학적 단일 다발 전방십자인대 재건술 후 임상적 결과를 분석하여 그 유용성을 평가하고자 한다. 대상 및 방법: 2009년 7월부터 2010년 7월까지 outside-in 술기를 이용하여 단일 다발 전방십자인대 재건술을 시행 후 1년 이상 추시가 가능한 41예를 대상으로 하였다. 평가는 International Knee Documentation Committee (IKDC) 주관적 슬관절 점수, Lysholm 점수, 축 이동 검사, one leg hop 검사, KT-1000 관절계검사, Telos 부하 검사를 이용하여 환자의 주관적, 객관적 증상을 평가하였다. 결과: IKDC 주관적 슬관절 점수, Lysholm점수는 각각 술후 평균 $86.1{\pm}2.1$, $91.2{\pm}3.8$으로 호전되었고(각각 p<0.0001, p<0.0001), KT-1000 관절계검사와 Telos 부하 검사에서도 술후 평균 $2.2{\pm}0.9\;mm$, $2.3{\pm}1.2\;mm$로 호전되었다(각각 p<0.0001, p<0.0001). 축 이동 검사와 one leg hop 검사에서도 술후 양호한 소견을 보였다. 결론: Outside-in 술기를 이용한 해부학적 단일 다발 전방십자인대 재건술은 임상적으로 좋은 결과를 보여 전방십자인대 수술에 있어 유용한 방법으로 생각된다.

• Nuclear Engineering and Technology
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• 제42권6호
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• pp.662-669
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• 2010

To develop the manufacturing methods for the blanket first wall (FW) of the International Thermonuclear Experimental Reactor (ITER) and to verify the integrity of the joint, Be/Cu mockups were fabricated and tested at the KoHLT-1 (Korea Heat Load Test facility), a graphite heater facility located at the Korea Atomic Energy Research Institute (KAERI). Since Be and Cu joining is the focus of the present study, the fabricated mockups had a CuCrZr heat sink joined with three Be tiles as an armor material, unlike the original ITER blanket FW, which has a stainless steel structure and coolant tubes. Hot isostatic pressing (HIP) was carried out at $580^{\circ}C$ and 100 MPa for 2 hours as the method for Be/Cu joining. Three interlayers, namely, $1{\mu}mCr/10{\mu}mCu$, $1{\mu}mTi/0.5{\mu}mCr/10{\mu}mCu$, and $5{\mu}mTi/10{\mu}mCu$ were applied as a coating to the Be tiles by a physical vapor deposition (PVD) method. A shear test was performed with the specimens, which were fabricated by the same methods as those used to fabricate the mockups. The average values were 125 MPa to 180 MPa, and the samples with the $1{\mu}mCr/10{\mu}mCu$ interlayer showed the lowest value. No defect or delamination was found in the joints of the mockups by the developed ultrasonic test using a flat-type probe with a 10 MHz frequency and a 0.25 inch diameter. High heat flux (HHF) tests were performed at $1.0\;MW/m^2$ heat flux for each mockup using the given conditions, and the results were analyzed by ANSYS-CFX code. For the test criteria, an expected fatigue lifetime about 1,000 cycles was obtained by analysis with ANSYS-mechanical code. Mockups using the interlayers of $1{\mu}mTi/0.5{\mu}mCr/10{\mu}mCu$ and $5{\mu}mTi/10{\mu}mCu$ survived up to 1,100 cycles over the required number of cycles. However, one of the Be tiles in the other two mockups using the $1{\mu}mCr/10{\mu}mCu$ interlayer was detached during the screening test, and others were detached by discharge after 862 cycles. The integrity of the joints using the proposed interlayers was proven by the HHF test, but the other interlayer requires more study before it can be used for the joining of Be to Cu. Moreover, it was confirmed that the measured temperatures agreed well with the analysis temperatures, which were used to estimate the lifetime and that the developed facility showed its capability of the long time operation.

• 한국환경복원기술학회지
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• 제10권6호
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• pp.139-151
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• 2007

To protect the surface of ground-cutting slopes and ground-raised slopes and to recover environment-friendly slopes at the national road expansion construction between Gamchon and Yaechon, test-construction work was done using several modes of hydro-seeding measures to select a suitable construction method through the field survey; the results were as follows : As a result of survey on physio-chemical characteristics of soil, the average soil inclination on ground-raised slopes was from 4.73 mm to 5.37 mm; the average soil acidity was from pH 6.47 to 6.73; the average soil humidity was within the scope of 0.57~1.70 %,; the average soil inclination on ground-cutting slopes was 9.17~10.43mm; the average soil acidity was pH 6.67~6.77 and the average soil humidity was within the scope of 0.53~1.27 %; considered overall, they showed generally satisfactory base materials for plant breeding. As a result of the number of sprouting individuals, the average sprouting number of individuals on test spots executed by Coir net with Seed spray construction methods and the average number of sprouting individuals on other test spots executed by furrow-digging with Seed spray and Straw mat-mulching measures were 1,172 number of per square meter and 970 number of per square meter respectively; thus they showed higher numerical value comparing with other test spots. Likewise, the average number of sprouting individuals on test spots of the ground-cutting slopes executed by Coir net with Seed spray method and the average number of sprouting individuals on other test spot executed by furrow-digger with Seed spray and Straw mat-mulching measures were found to be 1,107 number of per square meter and 1,105 number of per square meter respectively, whose numerical value showed rather higher other test spots. As a result of a survey on living plants' breeding index [dried weight], the weight in dried state on test spots executed by Coir net with Seed spray method and other test spots executed by furrow-digger with Seed spray and Straw mat-mulching measures on both ground-raised and ground-cutting slopes was found to be higher and showed similar characteristics statistically. As a result of survey on the surface-covering degree of ground-raised slopes, nine weeks after test construction, test spots executed by Coir net with Seed spray method and other test spots executed by furrow-digger with Seed spray and Straw mat-mulching measures showed commonly more than 70% of surface-covering degree, but other test spots showed only below 35% of surface covering degree; especially in case of test spots by Verdvol seed spray measures, they showed 10% of the lowest surface-covering. Surface-covering degree on the test spot of ground-cutting slopes nine weeks after test construction showed more than 75% both executed by Coir net with Seed spray construction method and executed by furrow-digger with Seed spray and Straw mat-mulching measures. As a result of survey on appearing plants on the test spots, there dominates Eragrostis curvula both on ground-raised slopes and on ground-cutting slopes with other seeding plant life's lower breeding and there appear intruders, such as Setaria viridis Beauv, Digitaria sanguinalis Scop, and Chenopodium album var.centrorubrum Makino. As for water-borne excavation and soil's washing-away on the slopes, there happened less washing-away and water-borne excavation with good breeding of plant life on test spots executed both by Coir net with Seed spray construction method and by furrow-digger with Seed spray and Straw mat-mulching measures, but there happened much more soil's washing-away along with water-home excavation at the test spot executed by Seed spray with measures. After the research results of test construction sites are examined overall, it's presumed that furrow-digger with Seed spray and Straw mat-mulching measures [interval between lines is 40cm, 5cm in depth] will be preferred to prevent erosion and water-home excavation of slopes located within the construction sites.