• Nuclear Engineering and Technology
• /
• 제14권1호
• /
• pp.10-16
• /
• 1982

액체특성구조이론을 액체 갈륨의 구조와 성질연구에 적용하였다. 이 연구에서 액체 Ga 속에는 $\beta$-Ga와 비슷한 구조와 $\alpha$-Ga와 비슷한 구조의 두가지가 있다는 가정을 하여 액체분배함수를 구하였다. 이를 사용하여 넓은 온도 범위에서 액체 Ga의 열역학적 및 수송학적 성질을 구하였다. 계산결과는 실험치와 잘 일치함을 보여주고 있다.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제49권2호
• /
• pp.267-279
• /
• 2010

Mathematics is the subject which is distinctive in logical hierarchy, so the dificiency of prior learning or lack of understanding can result in learning disabilities of follow-up study. To minimize the learning disabilities, we should percieve student's problems and correct them through "Error Analysis" so that they can make up meaningful learning. Especially, in the case of division, its meaning is various, and the interpretation of the quotient and the remainder is the difference according to the caculation results, so students are likely to make errors often. Therefore, in this study, I presented the measures of how to instruct them under the circumstances in which division is applied by analyzing examples of incorrect answers.

• 한국언어정보학회지:언어와정보
• /
• 제9권1호
• /
• pp.69-92
• /
• 2005

Pattern recognition in cognitive agents is based on (i) the uninterpreted input data (e.g. parameter values) provided by the agent's hardware devices and (ii) and interpreted patterns (e.g. templates) provided by the agent's memory. Computationally, the task consists in finding the memory data corresponding best to the input data, for any given input. Once the best fitting memory data have been found, the input is recognized by applying to it the interpretation which happens to be stored with the memorized pattern. This paper presents a fast converging procedure which starts from a few initially recognized items and then analyzes the remainder of the input by systematically checking for items shown by memory to have been related to the initial items in previous encounters. In this way, known patterns are tried first, and only when they have been exhausted, an elementary exploration of the input is commenced. Efficiency is improved further by choosing the candidate to be tested next according to frequency.

• 한국통신학회논문지
• /
• 제16권9호
• /
• pp.828-837
• /
• 1991

본 논문에서는 CCITT에서 채택된 X.2.5 network과 IBM이 채택한 System network architecture(SNA)의 synchronous data link control(SDLC)간의 protocol converter의 성능 분석을 한다. 여기서 protocol converter의 link level map-ping method를 사용하여 구현 되었다고 가정한다. 성능 분석을 통하여 각종 parameter에 대한 throughput과 mean waiting time을 구하며, 다양한 paramerter에 대하여 최적의 값을 조사한다. 특히 converter가 추정한 SDLC frame이 X.25. network packetizing과 규정한 최대 data packet size 보다 더 클 경우에 frame을 분할하게 되는데. 분할방식에 있어서 full and remainder packetzing과 equal packetizing 도입하여 서로간의 성능을 비교한다. message를 분할 할 때 조격으로 나누는 것이 frame의 오류를 줄일 수 있기 때문에 전자보다 후자가 성능면에서 우수함을 알 수 있다.

• Bulletin of the Korean Chemical Society
• /
• 제22권5호
• /
• pp.507-513
• /
• 2001

Histones, nuclear proteins that interact with DNA to form nucleosomes, are essential for both the regulation of transcription and the packaging of DNA within chromosomes. The N-terminal domain of histone H4 which contains four acetylation sites at lysines, may play a separate role in chromatin structure from the remainder of the H4 chain. NMR data suggest that H4NTP peptide does have relating disordered structure at physiological pH, however, it has a defined structure at lower pH conditions. The solution structure calculated from NMR data shows a well structured region comprising residues of Val21-Asp24. In addition, our results suggest that the H4NTP prefers an extended backbone conformation at acetylation sites, however, it (especially Lys 12 ) became more defined structures after acetylation for its optimum function.

• 대한수학회논문집
• /
• 제37권3호
• /
• pp.939-955
• /
• 2022

In this paper, we study a first-order non-linear singularly perturbed Volterra integro-differential equation (SPVIDE). We discretize the problem by a uniform difference scheme on a Bakhvalov-Shishkin mesh. The scheme is constructed by the method of integral identities with exponential basis functions and integral terms are handled with interpolating quadrature rules with remainder terms. An effective quasi-linearization technique is employed for the algorithm. We establish the error estimates and demonstrate that the scheme on Bakhvalov-Shishkin mesh is O(N^-1) uniformly convergent, where N is the mesh parameter. The numerical results on a couple of examples are also provided to confirm the theoretical analysis.

• 대한약리학회지
• /
• 제19권2호
• /
• pp.45-55
• /
• 1983

뇌내 여러 신경전달물질계가 시상하부-뇌하수체-부신계(HPA)를 복잡하게 조절하고 있다는 증거가 많이 나오고 있다. 그 중에서도 5-HT(Serotonin)계의 stress시의 역할에 대해서는 많은 연구가 있어왔으나 아직 논란이 많이 제기되고 있다. 따라서 저자는 5-HT가 stress시 HPA axis를 조절하는데 필수적인 역할을 하는가를 말아보기 위해서 1) Stress전후에 5-HT의 steady state농도와 5-HT의 교체율(turnover rate) 및 합성율(synthesis rate)을 측정해 보았으며 2) 비교적 5-HT계에 특이하게 작용하는 여러 약물들을 주사한 후에 stress 반응을 측정해 보았다. 1) 1분간 ether stress 가한 직후에 시상하부와 다른 뇌부위에서의 5-HT와 5-HIAA농도는 즉각적으로 의미있게 상승하였으나 혈장 corticosterone농도는 즉각상승을 보이지 않다가 2분후에 상승을 보였다. 2) Stress(30분 immobilization & 1분 ether stress)가한 백서에서는 시상하부와 다른 뇌부위에서 5-HT합성을 혹은 교체율이 2배-4배까지 상승하였다. 3) 5-HT합성 전구물질(L-tryptophan)과 수용체 자극제 (5-MeODMT)를 투여하였을 때는 투여용량에 비례해서 혈장 corticosterone함량이 상승하였다. 4) L-tryptophan과 MAO억제제 (pargyline) 혹은 L-tryptophan과 5-MeODMT의 병합 투여로 stress시 혈장 corticosterone의 상승이 더 높게 나타났다. 5) 5-HT 합성억제제(PCPA), 5-HT 신경독약(5,7-DHT)을 투여하고 stress를 가하였을 때는 시상하부와 다른 뇌 부위에서 5-HT의 하강이 별로 나타나지 않았으며, 동시에 혈장 corticosterone의 하강도 의미있게 나타나지 않았다. 그러나 midline raphe핵을 파괴하였을 때는 5-HT와 corticosterone의 하강이 나타났다. 6) 비교적 특이하게 serotonin제에 작용하는 여러 약물들을 투여한 후에 나타나는 5-T와 혈장 corticosterone함량 사이에는 상당히 높은 양의 상관관계계가 있었다(r>0.81). 이상의 결과를 종합해 볼때 serotonin(5-HT)은 시상하부-뇌하수체-부신계의 스트레스반응조절에 중요한 자극적 역할을 하리라고 생각된다.

• 한국환경농학회지
• /
• 제30권2호
• /
• pp.132-137
• /
• 2011

노지 캠벨얼리(Vitislabrusca L.) 포도원에서 관비재배시 토양검정시비량을 이용한 칼륨관비가 수체의 생육과 수량에 미치는 영향을 알기 위하여 2008년부터 2009년까지 2년간 사양토 노지 포도원에서 시험을 수행하였다. 시험 처리를 위해 먼저 토양검정을 통한 칼륨시비량(125 kg/ha)을 산출 후 칼륨시비량의 30%(37.5 kg/ha)는 기비로 모든 처리구에 시용 후 나머지 추비 시용량에 대해 표층 시비구는 농가 관행 표층 시비하였으며 관비구는 기존과원의 점적시설을 이용하여 처리 수준별로 생육기간 중에 나눠서 추비하였으며, K0(K 0 mg/L, 0 kg/ha), K1/4(K 25 mg/L, 21.9 kg/ha), K 1/2(K 50 mg/L, 43.8 kg/ha, K 1(K 100 mg/L, 87.5 kg/ha)등 관행구를 포함한 5처리를 난괴법 3반복으로 배치하여 시험처리구별로 관비하였다. 칼륨 이외의 인산과 질소에 대해서는 관행적인 방법으로 시비하였다. 토양검정 칼륨시비량을 기준으로 칼륨관비 처리결과 기비 30% 시비 후 추비 시용량에 대해 1/2 수준에서 관비한 50 mg/L 칼륨 관비 처리구가 관행구 대비 신초경경, 신초장과 같은 신초 생육이 좋았으며 칼륨관비처리에 따른 엽내 무기성분에 있어서는 K0 처리구가 칼리 함량이 유의하게 낮았다. 수량에 있어서는 2008년에는 처리간 차이가 없었으나 2009년에는 표층시비에 비해 칼륨 50 mg/L 관비구인 K1/2 처리구가 유의하게 수량이 좋았다. 이상의 결과를 통하여 봤을때 포도 캠벨얼리 관비재배를 위해 칼륨 관비시 토양검정시비량을 기준으로 칼륨의 기비 30% 시비 후 추비시용량의 1/2수준에서 50 mg/L의 관비 농도로 관비를 한다면 적절한 수체관리와 수량 및 칼륨비료 절감효과를 얻을 수 있을 것으로 판단된다.

• Journal of Chest Surgery
• /
• 제6권2호
• /
• pp.131-142
• /
• 1973

Studies of cardiopulmonary function and acid-base balance were performed on 29 dogs during control period, during oligemic hypotension and following return of blood to the animals. Intravenous morphine and local anesthesia were used. Fifteen of the 29 animals survived the complete experiment. The 14 animals that failed to survive the experimental period died between 15 to 90 minutes after the onset of bleeding. The results were as follows. 1. The heart rate increased after the onset of bleeding and failed to return to control level following reinfusion. Stroke volume decreased markedly after bleeding and failed to recover after return of blood from the reservoir. Cardiac output also decreased during oligemic hypotension and was maintained at this level after re-infusion. Total peripheral resistance decreased significantly immediately after bleeding, however it increased soon over the pre-bleeding level. Central venous pressure decreased after the onset of bleeding and remained at lower level for the rest of the experimental period. Arterial blood pressure, clown to 40-45 mmHg by acute hemorrhage, was elevated near to control level. Left ventricular work decreased tremendously during oligemic hypotension and failed to return to control level with the re-infusion of blood. Hematocrit value showed no significant decrease after bleeding and increased after re-infusion. Hemoglobin decreased after the onset of bleeding and recovered to control value after re-infusion. 2. The respiratory rate fell rapidly after bleeding from 124 to 29 and remained at this lower level for the remainder of the experiment. The tidal volume increased after bleeding and was maintained at this level for the remainder of the experiment. The respiratory minute volume showed no significant changes throughout the experimental period. Oxygen consumption fell lightly in all animals during oligemic hypotension and returned to normal levels following re-infusion. Arterial oxygen content and arterial oxygen saturation decreased following bleeding and the values returned to normal levels after the return of blood from the reservoir The arterio-venous oxygen difference increased after the onset of bleeding. It failed to return to normal values following re-infusion. Arterial $Pco_2$ decreased in all animals after the beginning of the bleeding. Partial pressure of $Co_2$ continued to fall until re-infusion, after which the values returned toward normal. Animals became acidotic. The pH fell to lower level following bleeding. Lactic acid and lactate: pyruvate ratio also increased during same period. Arterial pH and lactic acid failed to return to control value and lactate: pyruvate ratio increased more after re-infusion. Sodium bicarbonate decreased after bleeding and returned to control value following re-infusion.

• 대한핵의학회지
• /
• 제16권2호
• /
• pp.63-70
• /
• 1982

To evaluate the diagnostic usefulness and significance of quantitative sacroiliac joint scintigraphy in the assessment of sacroiliitis, we measured Sacroiliac Joint/Sacrum Uptake Ratio(SIS Ratio) by region of interest(ROI) method using $^{99m}Tc-methylene$ diphosphonate. The observed results were as follows: 1. Using ROI method, the SIS ratios for the control group of 65 persons were $1.05{\pm}0.08$(left) and $1.06{\pm}0.07$(right) which were narrower in range than those of slice method $(mean{\pm}S.D.)$. 2. The effects of age, gender and laterality on SIS ratio were not significant. 3. In left side, one of 6 patients with rheumatoid arthritis had SIS ratio in excess of 2 standard deviation of normal control group, and remainder had SIS ratios within normal limit. In right side, 3 patients had SIS ratios in excess of 2 standard deviation of normal control group, and remainder, within normal limit. 4. In both sacroiliac joint, 2 of 3 patients having sacroiliitis clinically with Reiter's syndrome whose pelvis A-P X-ray findings showed normal had high SIS ratios (left/right; 1.31/1.69, 1.90/1.80), but SIS ratio of one patient who had no evidence of sacroiliitis clinically was within normal limit. 5. In 6 patients with ankylosing spondylitis in both sacroiliac joints, 4 whose pelvis A-P Xray findings showed severe sclerotic change of sacroiliac joints had SIS ratio within normal limit or below that of normal control group, and SIS ratios of 2 patients whose pelvis A-P X-ray findings showed were increased. 6. 4 of 5 patients with low back pain of which cause could not be evaluated clinically and radiologically had SIS ratios in excess of that of normal control group. It would be concluded that quantitative sacroiliac joint scintigraphy is useful and sensitive screening method in the diagnosis as well as in the assessment clinical activity of sacroiliitis.