Device-line-measurement 방법을 이용한 Hair-pin 발진기 설계에 관한 연구

남장현,양승인 崇實大學校 2000 論文集 Vol.30 No.1

In this paper, a hair-pin resonator is designed by using an EM simulator(Microwave Office 2000). The design method of an oscillator is the device-line-measurement which determines the optimum impedance for maximum power of a negative-resistance device. This method can be adapted for use with HB simulators to determine output power and to specify the oscillation frequency. The maximum power and phase noise(10KHz Offset) is 10.17dBm and -63.20dBc/Hz respectively at the oscillation frequency of 11.52 GHz.

음악유형에 따른 태권도 품새시 운동강도와 정서변화

이선장,박남환,강승호 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

The purpose of this study was to invesigate the effects of music types on the relative intensity(heart rate) and variation of mood state in taekwondo poomse training. ten apparently healthy volunteers from keimyung university taekwondo student signed a standard informed consent to participate in this study. Each subject performed the taekwondo poomse(teaguc poomse 1-8) two times following positve and nagative music and white noise in a random order for 8-9min at a pace that would be used during normal training. the music samples were differently associated with emotion. fast-tempo, loud song were rate as positive and slow-tempo, soft songs were identified as nagative. To evaluate HRmax, it was use graded maximal test, continuous heart rate measures were recorded throughout the teakwondo poomse drill with recovery period. the variation of mood state were investigated by question-naire. The experimental data was analyzed by one-way ANOVA with repeated measures. Based on the finding of the study, the following conclusion has been derived. 1. The change of the heart rate during taekwondo poomse drill: HR as exercise intensity of movement of taekwondo drill, fast-tempo, loud song group have shown significantly higher(p<.01) than white noise and soft song group at various periods. 2. The change of the RPE during taekwondo poomse drill: White noise and soft song groups were significantly lower(p<.01) than fast-tempo, loud song group during taekwondo poomse drill 3. The change of the mood state after taekwondo poomse drill: Tension of mood state was siginificant difference between white noise and soft song group but other variable were no significant differences in groups. In conclusion, this study provides some support the hypothesis that fast, loud music increase physiological (heart rate) or psychological arouse.(Mood state)

초등학교 과학 수행평가에 대한 교사의 인식

서승조,조태호,백남권,박강은,김성규,박장서 晋州敎育大學校 科學敎育硏究所 2001 科學敎育硏究 Vol.27 No.-

The purposes of this study are to examine how Science Performance Assesment is being well conducted in elementary schools and to check the teachers' awareness through surveying the actual condition. To achieve this purpose, the author, in this study, distributed questionnaire developed by researcher under supervision of academic advisor to the elementary school teachers in Gyeongnam province. Based on the data. the research results were mainly analyzed by the statistical method using Chi-square test. The survey was consisted of questions which was designed to perceive teachers' awareness about elementary school science performance assessment. The main findings of this study are summarized as follows', 1. Elementary teacher's are doing affirmative estimation about induction of performance assessment. 2. Most teacher are recognizing performance assessment right and teachers' understanding appeared high. 3. Material development of performance assessment is recognizing that people who have opinion which is special must develop. 4. The biggest problem of performance assessment fixing is recognizing that number of persons per class are many and amount of training courses is much also with the tribe during time. 5. It was recognizing positively whether it is in class improvement of performance assessment effect. 6. Teachers had awareness that confirm studies accomplishment degree through performance assessment, or will utilize to improvement material of teaching-learning method.

40세 이하 관상동맥 질환자에서 장기적 임상 관찰

이승욱,정명호,박종철,박형욱,조상희,김원,김계훈,이상현,강경태,조장현,김남호,김건형,안영근,조정관,박종춘,강정채 全南大醫大 2001 전남의대학술지 Vol.37 No.2

분말야금법으로 제조된 2124AI 합금의 빠른변형률속도 초소성 거동

金祐塡,張勝彦,南勝義,金亨駿 弘益大學校 科學基術硏究所 1999 科學技術硏究論文集 Vol.10 No.2

Ceramic whisker or particulate reinforced aluminum based metal matrix composites show high room temperature strength, but their low formability makes it difficult to form into desired shapes. By superplastic deformation, their formability can be improved and it is possible to produce complex parts for automotive aerospace simultaneously instead of many near-net-shape forming operations. This study has been carried out to investigate the high temperature mechanical and superplastic properties in 2124Al alloy. SRC(Strain Rate Change) tests show that the value of n(stress exponent) is around 3 at high strain rate and above 5 at low strain rate. It was turned out that 212Al matrix alloy exhibited reasonably high tensile elongation above 250% with the broad range of temperature and strain rate. Especially, at 550℃, both materials showed very high elongation failure up to 700% for 2124Al alloy. The strength comparison is lower strength then 2124Al composites were obtained that the composite is lower strength than 2124Al alloy at superplastic region.

실내 기후동에서 개인형 국소냉방 장치의 기류 및 온도 분포해석

엄태인,장은숙,경남호,신기식,문승현,전영남,류창국 한밭대학교 생산기반기술연구소 2002 생산기반기술연구소 논문집 Vol.2 No.1

Numerical simulation is performed by the commercial code FLUENT for individual air condition system to calculate the velocity and temperature profiles around worker in climate room. The main calculation region is the space of ㄱ shape between wall and worker in the individual air condition system. The fresh air is emitted from 3 inlet attached on the right, left and center wall. Because the comfort of worker is closely related with the velocity and temperature of wind, these data are key role for design of the individual air condition system. This work is previous study for evaluation of thermal comfort of workers in room without much experiments according to metabolism and heat emission of human body. Numerical simulation results are as followings, 1. There is an possibility of the thermal comfort of worker is gotten worse due to the presence of dramatic change of wind velocity around worker. 2. Temperature gap exists in worker's body between top and bottom according to fresh air inlet velocity and position which is right, left and center of wall. 3. Calculation results of the skin temperature of worker are key data for evaluation of thermal comfort with experimental data in climate room. 4. Optimum condition of temperature, direction and velocity of fresh air will be obtain by numerical simulation for energy effective individual air condition system.

고주파수대역에 적용되는 Fe-( BN, Si₃N₄)박막의 미세구조와 자기적특성에 관한 연구

申東勳,張勝彦,李宰源,南勝義 弘益大學校 科學技術硏究所 1997 科學技術硏究論文集 Vol.8 No.-

We have investigated the magnetic properties of FeBN thin films deposited by using RF magnetron sputtering and Fe-BN composite target. It was investigated that the area fraction of BN chips on the Fe target and partial pressure of nitrogen was the main factors influencing the soft magnetic properties and resistivity of FeBN thin film. The low addition of N₂increases significantly the soft magnetic properties and electrical resistivity. The good soft magnetic properties are obtained at N₂partial pressure of 5%, but futher increase in N₂ partial pressure degrade the soft magnetic properties due to formation of nitrides such as Fe₄N, Fe₂∼₃N. In a sputtering process, as the area fraction of BN increases, FeBN thin films fabricated at the area fraction of 0.25 exhibt soft magnetic properties (Bs∼17kG, Hc∼10e, μ∼1000).

하지의 동맥부전증 환자에서 동반된 복부 대동맥류

문인성,박장상,고용복,김용귀,홍성곤,김승남 대한혈관외과학회 1999 Vascular Specialist International Vol.15 No.1

The early diagnosis of abdominal aortic aneurysms are difficult, especially when they are not clinically evident. Because of the generalized nature of atherosclerosis, there is reason to believe that there is a high incidence of aneurysms of the abdominal aorta in patients with peripheral vascular disease. But the screening test for hidden abdominal aortic aneurysms in patients with peripheral arterial disease has not been used for routine manner. So we retrospectively reviewed the 9 patients who had asymptomatic abdominal aortic aneurysms with symptomatic peripheral arterial disease during the last four and half-year period: among them three aneurysms were screened preoperatively by physical examination with their diameter more than 5 cm and 6 aneurysms were found intraoperatively with their mean diameter of 3.8cm. The ages ranged from 66 through 84 years with the mean age 73 years. There were 7 men and 2 women. The sites of the peripheral occlusive disease is as follows: femoral artery only in 1, iliac artery only in 2, both iliac and femoral arteries in 5, and from iliac artery through tibial artery with thrombus formation in 1. We suggest that ultrasonographic screening for the presence of hidden abdominal aortic aneurysm preoperatively in patients with lower extremity occlusive arterial disease is needed, especially when the ages of patients is older than 65 years and the site of arterial disease include iliac segment.

Wolff-Parkinson-White증후군의 임상상 및 전기생리학적 소견

안신기,이문형,장양수,오동진,최인석,하종원,임세중,김병옥,정남식,심원흠,조승연,김성순 대한순환기학회 1997 Korean Circulation Journal Vol.27 No.9

굴껍질을 이용한 고농도 중금속 폐수처리에 미치는 pH의 영향

성낙창,신남철,최장승 동아대학교 환경문제연구소 1996 硏究報告 Vol.19 No.2

The purpose of this research is to examine the utilization of oyster shells for the removal of high concentrated heavy metals in an acidic·alkali system wastewater. because oyster shells have been known to be very porous, to have high specific surface area and to have alkaline minerals such as calcium and mangnesium. It could be showed that most of heavy metals intended to increase removal rate with pH increase, but maintained equilibrium and heavy metals were removed high. In 7g and 9g, desorptions were caused by the weak physical coherence of heavy metals. Solubilites of heavy metals increased with Fe>Cu>Cr and Fe removal rate was higher than other heavy metals, because removal rate was influenced by- competitive reaction in same pH rather than solubility. In point of Ocean waste recyling, if oyster shells will use wastewater treatment of acidic and high concentrated heavy metals, they could look forward to an expected economical effect.