LTCC 기술을 이용한 광대역 3㏈ 결합기 설계 및 제작

황희용,조정훈 강원대학교 정보통신연구소 2005 정보통신논문지 Vol.9 No.-

This paper presents a 3 dB wideband tandem quadrature coupler fabricated by LTCC technology. The 3 dB tandem coupler was designed with minimum numbers of layers and via holes to reduce the cost and to increase yield on manufacturing. Since tight coupling value is easily achievable with the tandem structure, any high impedance lines or tight coupling gaps can be avoided. The simulated and measured data shows wide bandwidth from 1.4 GHz to 2.4 GHz with 0.3 dB amplitude imbalance, phase difference within 1.5 degree, and the isolation characteristics about 20 dB. The size of fabricated 3dB coupler is 9.64×10.42×1.74㎣.

두가지 혈류 유발방법에 의한 새로운 심폐소생술(이중 혈류 유발 심폐소생술)장치의 개발

황성오,김현,조준휘,오범진,임종천,최경훈,윤정한,이승환,김영식,이강현,이윤선 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Background: There have been many efforts to augment blood flow during cardiopulmonary resuscitation. These efforts have focused on maximizing the effect of cardiac pump or thoracic pump alone. However, considering that the heart is the biggest blood reservoir and increase of intrathoracic pressure can generate blood flow, simultaneous exploitation of both mechanisms may have synergistic effect. We hypothesized that simultaneous chest constriction in addition to sternal compression by standard CPR may have additive hemodynamic effects by preventing deformation of the chest and increase of intrathoracic pressure. Methods and results: we built a new mechanical device to perform compression and thoracic constriction simultaneously. The device consists of two main elements. Piston in the center is to depress the sternum. Strap is to constrict the thorax circumferentially. Strap is attached to both sides of the piston. When the piston is pushed down, it depresses the sternum and pulls on the thoracic strap. To determine strap width to produce optimal hemodynamic effect, we measured hemodynamic parameters with variable widths of strap in two dogs after induction of ventricular fibrillation. Result of the experiment showed that 10cm wide strap was determined to be most effective. We also determined optimal depth of compression to produce maximal hemodynamic effect with animal experiments using two dogs. Animal experiments showed that the highest aortic pressure could be generated when the stemum was depressed to 5 cm. Cardiopulmonary resusciation using a new device could generate higher systolic aortic pressure, coronary perfusion pressure and end-tidal carbon dioxide tension in comparison with standard cardiopulmonary resuscitation in a pilot animal study using two dogs. Conclusion: New cardiopulmonary resuscitation method using a mechanical device designed by us could perform sternal compression and simultaneous thoracic constriction, and generate better hemodynamic effects than standard cardiopulmonary resuscitation in pilot animal experiments.

축구선수의 Detraining과 Retraining이 혈청지질 및 호르몬농도에 미치는 영향

정정화,박재현,채종훈,성혜련,황지인,윤미숙,노금선,윤종관,윤영학,노순덕,정경숙,박일규,김은희,박현태,박상갑 대한스포츠의학회 1999 대한스포츠의학회지 Vol.17 No.1

The purpose of this study was to investigate the effects of detraining and retraining on serum lipid and hormones in soccer players. Subjects were seven male high-school soccer players. V˙O_2max was determined for each subjects by administering a treadmill test(initial speed: 90m/min, grade: 5%, increasing speed per 3 min: 30m/min). Serum lipid(T-C, TG, HDL-C LDL-C) and hormones(epinephrine, norepinephrine, growth hormones, cortisol) were assayed pre and post detraining in 10, 20, 30 days after retraining. The repeated ANOVA was used to determine significant differences. The 0.05 level of significance was as critical level for the study. The results of the study were as follows: 1. V˙O_2max(ml/min) were 3576.3±204.2ml/min pre detraining, 3234.1±198.9 ml/min post detraining. There are significant(p<.05) difference between pre and post detraining. In 10, 20, 30 days after retraining, V˙O_2max(ml/min) were 3601.4±170.9 ml/min. There were significantly(p<.05) increased in retraining periods. 2. V˙O_2max(ml/kg/min) were significantly(p<.05) decreased from 62.3±2.9 ml/kg/min to 55.9±4.7 ml/kg/min in detraining. In 10, 20, 30 days after retraining, V˙O_2max(ml/kg/min) were 62.4±3.4ml/kg/min, 62.7±2.3ml.kg/min, 67.3±7.2ml/kg/min respectively. There were significantly(p<.05) increased in retraining periods. 3. T-C were significantly (p<.05) increased from 166.6±8.5mg/dl to 175.3±10.3 mg/dl in detraining. In 10, 20, 30 days after retraining, T-C were 160.1± 3.2mg/dl, 156.7±3.7mg/dl, 140.3±9.0mg/dl. There were significantly(p<.05) decreased in retraining periods. 4. HDL-C were 61.4±6.6mg/di pre detraining, 5.3±6.6mg/dl post detraining. There are significant(p<.05) difference between pre and post detraining. In 10, 20, 30 days after retraining, HDL-C were 56.9±7.1mg/dl, 56.4±9.2mg/dl, 57.7±9.1mg/dl respectively. There were no significant difference in retraining periods. 5. The hormones(epinephrine. norepinephrine, growth hormone, cortisol) were changed as same patterns. Epinephrine were 26.0±7.0[g/ml pre detraining, 24.6±3.2pg/ml post detraining. In 10, 20, 30 days after retraining, epinephrine were 26.9±5.6pg/ml, 30.6±6.2pg/ml, 29.4±5.6pg/ml respectively. There were no significant difference in retraining periods. In conclusion, HDL-C, epinephrine, norepinephrine, growth hormone and cortisol were decreased, T-C, LDL-C and TG were increased in detraining. But HDL-C, epinephrine, norepinephrine, growth hormone and cortisol were increased, T-C, LDL-C and TG were decreased in retraining.

미맹출 영구 견치 및 소구치 근원심 폭경 추정에 관한 연구

황민성,김정욱,장기택,이상훈 大韓小兒齒科學會 2002 大韓小兒齒科學會誌 Vol.29 No.1

본 연구는 서울시 치과의사횡에서 주관한 건치아동 선발대회 후보의 경석고모형 162쌍을 분석하여 성별에 따라 하악 영구 4전치 근원심 치관 폭경합의 계측치에서 상악 및 하악의 편측 영구 견치 및 제 1, 2 소구치 근원심 폭경합을 추정하는 회귀방정식과 확률표를 구하였다. 그리고 성별간 차이를 비교하여 다음과 같은 결과를 얻었다. 1. 남자와 여자 모두 동일한 악궁 내에서 좌우측 영구 견치 및 소구치의 폭경합은 유의한 차이가 없었다.(p>0.05). 남녀간의 상하악 좌우측 영구 견치 및 소구치의 폭경합의 계측치(x)에서 상악 및 하악의 편측 영구 견치 및 제 1, 2 소구치의 근원심 폭경합(y)을 추정하기 위한 회귀 방정식은 다음과 같았다. 남자 상악 영구 견치 및 소구치 폭경합 : y=10.45+0.53x 남자 하악 영구 견치 및 소구치 폭경합 : y=10.07+0.51x 여자 상악 영구 견치 및 소구치 폭경합 : y=12.65+0.42x 여자 하악 영구 견치 및 소구치 폭경합 : y=11.70+0.42x 남자+여자 상악 영구 견치 및 소구치 폭경합 : y=11.01+0.50x 남자+여자 하악 영구 견치 및 소구치 폭경합 : y=9.87+0.51x The purpose of this study was to establish regression equations and probability charts for predicting the summ of mesiodistal crown diameters of unerupted unilateral canine and premolars from the sum of mesiodistal crown diameters of four mandibular incisors in Korean male and female. The plaster casts of 162 children(75 boys and 87 girls) among the contestees in 1994-2001 Healthy Dentition Contest in Seoul were measured. Sex differences are compare and the following results were obtained: 1. Bilateral comparison of sum of widths of permanent canine and premolars showed no significant differences for either sex(p>0.05). Sum of widths of permanent canine and premolars of male were significantly larger than that of female(p<0.01). 2. Regression equations for the prediction of sum of widths of permanent canine and premolars in each sex were as follows: Male ∑ Maxillary 345 : y=10.45+0.53x Male ∑ Mandibular 345 : y=10.07+0.51x Female ∑ Maxillary 345 : y=12.65+0.42x Female ∑ Mandibular 345 : y=11.70+0.42x Male+female ∑ Maxillary 345 : y=11.01+0.50x Male+female ∑ Mandibular 345 : y=9.87+0.51x

이중혈류유발 심폐소생술이 심정지를 유발한 개의 단기 생존율에 미치는 영향

황성오,조준휘,강구현,김성환,문중범,이강현,이승환,윤정한,최경훈,홍은석 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background and Objectives: We previously reported that, compared with standard cardiopulmonary resuscitation(S-CPR), better hemodynamic effects could be achieved by simultaneous sterno-thoracic cardiopulmonary resuscitation(SST-CPR) in which we compressed the sternum and constricted the thorax circumferentially during the systolic period by using a device. This study was designed to assess whether SST-CPR, compared with S-CPR, improve the survival rate of dogs with cardiac arrest. Subjects and methods: Twenty-five mongrel dogs(19∼31㎏) were enrolled in this study. After four minutes of ventricular fibrillation induced by an AC current, animals were randomized to resuscitate with either S-CPR(n=13) or SST-CPR(n=12). Epinephrine(1 ㎎) was injected into the right atrium every three minutes after the beginning of CPR. Defibrillation was attempted after 6 minutes of CPR. Standard advanced cardiac life support was started if defibrillation was not successful. Results: SST-CPR resulted in significantly(p<0.001) higher systolic arterial pressure(91±47 vs 47±24 ㎜ Hg), diastolic pressure(43±24 vs 17±10 ㎜ Hg), coronary perfusion pressure(35±25 vs 13±9㎜ Hg), and end tidal CO2 tension(9±4 vs 3±2 ㎜ Hg). Two of 13 animals(15 %) resuscitated with S-CPR and six of 12 animals(50%) resuscitated with SST-CPR survived until 12 hours after cardiac arrest(p<0.05). Donclusion: SST-CPR, compared with S-CPR, improves the short-term survival rate in canine cardiac arrest.

지진의 영향을 고려한 영팽창선이론에 의한 얕은기초의 지지력해석

黃正奎,申東勳 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.4 No.-

The present study was made based on the zero extension line theory and the seismic coefficient method to determine the seismic bearing capacity of shallow foundation. The zero extension line theory, which was proposed by Roscoe et al., presumes the coincidence between the loci of failure and the zero extension lines in soil mass. In order to compute the seismic bearing capacity of shallow foundation with smooth base mobilized by an earthquake, it was assumed that subsoils beneath the foundation are dense and cohesionless sandy soils, there are no changes in soil parameters during earthquake, and only horizontal earthquake intensity is considered. The presented theories were successfully compared with the conventional bearing capacity theories. And the effects of embedment depth of footing, earthquake intensity, dilation angle and internal friction angle of soil, on the bearing capacity factors were analysed. Finally a simplified formula for bearing capacity factor of N?? in earthquake was also provided.

경구용 액체약의 함유된 감미제의 종류와 함량

황민성,김정욱,이상훈 大韓小兒齒科學會 2001 大韓小兒齒科學會誌 Vol.28 No.4

치아우식증을 예방하기 위해 당분을 포함한 음식의 사용을 조절해야 한다는 것에는 동의하지만 어쩔 수 없이 인지되지 못한 체 액체약에 포함된 형태로 공급되는 상당량의 당분이 존재한다. 당분을 포함한 액체약을 장기간 복용할 때는 우식 발생의 위험성이 증가될 수 있다. 본 연구는 경구용 액체약을 처방받는 경우를 고려하여 약제를 통한 당분의 섭취량에 대한 정보를 얻어 치아우식증의 예방에 도움을 주고자 조사를 하였다. 본 연구는 서울대병원 어린이병원에서 처방된 경구용 액체약을 조사하여 소아 환아에서 흔히 사용되는 액체약의 목록을 구하였고, 현재 국내에서 시판되고 있는 액체약을 기준으로 각 제조사에 자료를 요청하여 생상중인 액체약에서 그 속에 함유된 감미제의 종류와 함량에 대해 조사하였다. 아동에서 흔히 사용되는 액체약은 진해거담제, 암모니아혈증 치료제, 항생제, 빈혈약, 진정제, 항히스타민제, 항전간제, 비마약성진통제의 순이었다. 액체약에 함유된 감미제의 평균함량은 52.3±22.4g/100ml이었다. 그리고, 액체약에 함유된 감미제 중 가장 많이 사용되는 것은 백당이었다. Though a consensus seems to exist about the regulation of the use of sugar-containing food, however, an unrecognized and significant supply of cariogenic carbohydrate remains in the form of sugar-containing liquid oral medicine to prevent dental caries, children who are taking long-term sugar-containing liquid medicine have an increased risk of developing dental caries. The aim of this study is to get the information about the sugars in liquid medicines prescribed for the children. To get the information, the number and date of all prescriptions of liquid medicines for one month at pediatric hospital of Seoul National University Hospital were investiagted. From tha tdata, the most frequently used pediatric oral liquid medicine is presented. Then, for the information of the type and contents of sweeteners in that preferred medicines, the manufactures of each medicines were asked for the data of sugar types and contents, and the informations about the medicine contents were collected via facsimile. The most frequently used pediatric oral liquid medicine were followed as expectorant, purge, antibiotic, drug for iron deficiency anemia, sedative, antihistamine, anticonvulsant, NSAIDs in order. The mean value of sweetener content in liquid medicines was 52.3±22.4g/100ml and most frequently used sweetener is sucrose.

창공91의 비행 시험을 통한 지면 효과 측정에 관한 연구

황명신,장욱진,이정훈 한국 항공대학교 항공산업기술연구소 1996 航空宇宙産業技術硏究所 硏究誌 Vol.6 No.-

창공-91 비행기를 이용하여 비교적 양항비가 큰 비행기의 지면 효과를 측정하는 연구를 수행하였다. 이착륙 중에는 지면에 의한 영향에 의해 공기역학적인 특성이 변화하며, 따라서 조종 특성에 많은 영향을 준다. 지면 효과에 대한 연구는 특히 시뮬레이터를 설계하는데 기초적인 자료로서 대단히 중요하지만 측정의 어려움 등으로 인하여 거의 연구 자료가 없다. 본 연구에서는 경비행기인 창공-91을 이용하여 여러 가지 비행 형태에 대해 지면 효과를 측정하기 위한 비행 시험을 수행하였다. 비행 형태는 실제 이착륙 조건을 고려하여 플랩 1단, 2단, 3단에 대하여 수행되었으며, 본 연구에서는 적은 비행회수로도 지면 효과를 측정할 수 있는 일정 받음각 방법을 이용하여 비행을 하였다. 실제 비행 시험 결과 지면 가까이에서 양력의 증가를 확인할 수 있었지만 항력과 키놀이 모멘트의 변화를 측정하기는 어려웠다. When an airplane flies close to the ground, at a height of one or two wing spans, it experiences an increase in lift and significant changes in drag and pitching moment. This phenomenon is known as ground effect. A study on the Ground Effect of Chang-Gong 91 was conducted by the flight test. Because of the obvious influence of ground proximity during the takeoff and landing phases, it has been the subject of considerable investigation, especially for simulator design. However, despite this consideration, an adequate amount of reliable ground-effects data does not appear in the literature. A Constant Angle of Attack approach technique was used to measure ground effect on several aircraft configuration. Test results indicate that ground proximity produces and increase in the lift-curve slope for Chang-Gong 91

전대역 매칭 특성을 갖는 대역통과 여파기 설계

황희용,조정훈 강원대학교 정보통신연구소 2005 정보통신논문지 Vol.9 No.-

This paper presents a design of all band matched BPF, which has impedance matched characteristics in pass band as well as its stop band. The BPF is a kind of balanced structure which is made of two wideband quadrature 3 dB couplers and two band pass filters. The experimental results of a balanced type band pass filter show impedance matched characteristics not only within the pass band of about 80 MHz but also at the stop bands from 1.0 GHz to 3.0 GHz including upper and lower stop band. This BPF could give system designers a new and easier way to eliminate multiple reflection problems in RF systems.

유전알고리즘을 이용한 철근콘크리트 보의 최적설계

한상훈,조홍동,박중열,황선일 충북대학교 건설기술연구소 2002 建設技術論文集 Vol.21 No.2

This paper describes the application of genetic algorithm for the optimum design of reinforced concrete beam. The cost of reinforced concrete beam as an objective function which includes the costs of concrete, formwork, tensile steel reinforcement and shear reinforcement is minimized. The flexural and shear strength, deflection, upper-lower bounds on steel reinforcement and beam width-depth ratio are considered as the constraints. For the check of the serviceability, deflection is calculated under the service loading by the effective moment of inertia instead of the gross moment of inertia. Optimum results obtained from GA are compared to verify the validity of GA with other literature. Then, GA is applied to 3 span RC beam based on standard specifications.