Bushing을 이용한 광대역 마이크로스트립 안테나 설계

양진모,최지훈 대구대학교 2006 대구대학교 학술논문집 Vol.1 No.2

일반적인 마이크로스트립 안테나는 높은 Q값으로 인해 5% 이내의 대역폭을 가진다. 이는 마이크로스트립 안테나의 가장 큰 단점이라 할 수 있다. 협대역이라는 문제점을 해결하기위하여 낮은 유전율의 기판을 사용하고, 유전체의 두께를 증가시키면서 부싱(bushing)을 삽입하는 방법을 이용하였다. 부싱은 유전체의 높이가 증가하면서 SMA 커넥터가 가지는 인덕턴스 성분을 제거하는 역할을 하게 된다. 유전체의 높이가 25mm일 때 부싱을 삽입하여 약 12%(114MHz)의 대역폭을 얻었다. A standard microstrip antenna has bandwidth within 5% because of high Q. This is the biggest shortcoming of microstrip antenna. In this paper, the method of inserting a bushing to the thick microstrip antenna with low permittivity substrate is proposed to improve the bandwidth of microstrip antennas. The bushing effectively removes the inductance of SMA connector that occur as the height of substrate increases. When the proposed busing technique is applied to the microstrip antenna whose thickness of dielectric substrate is 25mm, the bandwidth of almost 12%(114MHz) was obtained.

고삼투압성 비케톤성 상태의 예후인자

안성훈,김양원,김미란,진헌철,안지영,이상래,류석용,김홍용,김성준,이병권,김경환 대한응급의학회 2001 대한응급의학회지 Vol.12 No.2

Background: A hyperosmolar nonketotic state has been known to have a high mortality, and even now, despite this high mortality, only a few studies of this disease have been performed. We studied the prognostic factors for the hyperosmolar nonketotic state. Methods: We retrospectively studied the cases of 40 patients who were in a hypersomolar nonketotic state when admitted to Sanggye Paik Hospital during the 6-year Period from 1995 through 2000. We divided the hyperosmolar nonketotic patients into two groups, the complete recovery group and the incomplete recovery group, and compared the clinical features, the laboratory findings, and the precipitating factors between two groups. Results: 1) A total of 40 patients were studied: 24 in the complete recovery group and 16 patients in the incomplete recovery group. The mortality rate was 32.5%. 2) No significant statistical difference existed among the clinical features of the two groups, except for the sex(p<0.01). 3) Among the laboratory findings of both groups, analysis revealed that the effective osmolarity was significantly higher among those in the incomplete recovery group(p<0.01). Serum sodium concentration was also significantly higher among those in the incomplete recovery group(p<0.01). Serum creatinine was also significantly higher among those in the incomplete recovery group(p<0.05). Serum bicarbonate concentration, on the other hand, was significantly lower among those in that group(p<0.05).4) Infection was identified as the most common precipitating factor(62.5%). Among the precipitating factors of the two groups, there were significant statistical difference in pneumonia, UTI, and inappropriate glucose control. 5) A significant statistical difference existed among the initial level of consciousness of both groups(p<0.05). 6) The only significant independent factor responsible for prognosis of nonketotic hyperosmolar state patients was the sex. Conclusion: The sex was only significant independent prognostic factor of nonketotic hyperosmolar state patients.

유기용제노출이 직업적 청력손실에 미치는 영향

이지호,고영주,이헌,강정학,유철인,이충렬,김양호 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.4

목적 : 산업 장에서 노출되는 유기용제가 청력역치에 어떠한 영향을 미치는가를 5년 동안의 추적조사를 통하여 파악하고자 하였다. 방 법 : 유기용제와 소음에 동시에 노출된 근로자 43명과 소음노출수준, 연령, 근무경력을 짝짓기 한소음노출군을 대상으로 문진과 이경검사, 소음노출 수준, 유기용제노출수준을 조사하였다. 결과 : 1. 전체 근로자의 각 주파수별 청력역치 변화양상에서 500Hz∼2000Hz에서는 추적기간 동 소음동안 현저한 변화가 없었고, 4000Hz 및 8000Hz에서는 역치가 증가하는 경향을 나타내었다. 2.유기용제와 소음에 동시에 노출된군에서 소음 노출군에 비해 4000Hz 이상에서 청력역치가 높게 나타났으나, 통계적인 유의성은 없었다(p(0.05). 3.반복측정 분산분석 법으로 각 주파수별 평균청력 역치의 연차적 변화에 미치는 영향을 분석한 결과 유기용제 노출은 통계적으로 유의한 영향이 없었으나(p)0.05), 소음노출수준은 250Hz, 2000Hz 및 4000Hz에서, 연령은 250Hz와 500Hz에서 통계학적으로 유의한 영향을 미치는 것으로 나타났다(p(0.05). 4.소음노출군파 동시노출군 각각에서의 청력역치 변화량을 paired t-test로 비교한 결과 250Hz∼4000Hz에서는 통계학적 유의성이 없었으며(p(0.1), 8000Hz에서만 경계치 (p=0.0884)의 유의성을 나타내었다. 5.요인들의 영향을 보정한 상태에서 관찰하기 위해 관찰기간동안의 청력역치변화량을 종속변수로 두고 일반선형모형을 이용하여 주파수별로 관찰한 결과 8000Hz에서만 모델에 통계학적 유의성이 있었으며 (p(0.05), 여기서 소음노출수준이 통계학적으로 유의한 영향을 미치는 것으로 나타났고(p(0.05), 유기용제노출은 경 계수준이 었다(p=0.087). 결론 : 청력에 대한 유기용제의 영향이 소음과 연령에 비해 상대적으로 미미하여 명확한 결론에 이르지는 못하였으나, 다소 영향이 있는 것으로 생각되어 유기용제의 영향에 대한 추가연구가 필요할 것으로 판단된다. 또한 보다 효과적인 근로자들의 청력관리를 위해서는 소음 외 산업 장에서 동시에 노출되는 여러 유해물질들을 고려하여야 할 것이다. Objectives : This study was to evaluate the impacts of simultaneous exposure to noise and mixed solvents on workers'hearing threshold level (HTL) over five-year period. Methods : The study was conducted by interview and annual audiometric test on workers in ship building industry from 1994 to 1998. The cases(workers who exposed to noise and mixed solvent simultaneously) were 43 male workers and controls (workers who exposed to nolle) were selected by matching method with regard to age, sex, carrier, and noise exposure level. To assess the impacts of solvent exposure on hearing threshold level, with considering other factors, general liner model was used. Results : 1. The audiogram of all subjects showed typical sensorineural hearing loss pattern. The mean HTLe were increased at high frequency (4000HB and 8000Hz) for study period. 2. The HTLs of cases were more increased than those of controls at high frequencies (4000Hz and 8000Hz), but there was not statlstical significance. 3. The impact of age on the HTL was statistically significant at 250Hz and 500Hz (p(0.05), and the impact of noise on the HTL was statistically significant at 250Hz, 2000Hz and 4000Hz (p(0.05), but the impact solvent exposure on the HTL was not significant. 4. The changes in HTLs of cases were higher than those of controls at high frequency, there were not statistical significance at 4000Hz, but only at 8000Hz (p=0.087). 5. Statistical analysis of the general linear model implicated that the changes in HTL was impacted by noise exposure bevel significantly (p=0.031) and Impacted by solvent exposure weakly (p=0.087) at 8000Hz. Conclusions : The results of this study suggest that workers who simultaneously exposed to noise and mixed solvent were at risk for more affected HTL than those exposed to noise exposure only, but we could not find definitive evidence. Further detailed studies must be made in large number of workers.

무선 ATM망에서의 동적 대역폭 할당 알고리즘에 대한 QoS 성능 연구

류기훈,김지연,전광탁,양해권 군산대학교 정보통신기술연구소 2000 情報通信技術硏究論文集 Vol.4 No.-

In the network with small cell radius, a mobile terminal which has large mobility should perform frequent handover. This requires that handover mechanism must be done fastly. As cell size is smaller, signal power level is lower Handover is implemented by the network to give the users freedom of motion beyond a limited wireless coverage area while they are communication. The handover is procedure by which a user's radio link is transferred from one radio port to another through the network without an interruption of the user collection. The currently existing method for handover uses an algorithm, in which the bandwidth corresponding to the adjacent cells is supposed to be allocated. However, this method leads to the problem of requiring bandwidth allocation for many-unknown cells, due to the lack of information toward moving direction in mobile terminal. In this paper, we propose an efficient dynamic bandwidth allocation algorithm for solving those problem above, based on both path rerouting handover and soft hangover mechanism with wireless ATM. Thus, only the bandwidth for corresponding adjacent cell, that is from estimation, is chosen to be reserved; this method drastically reduces the waste of bandwidth, and improves the efficiency in performance. Comparing with static bandwidth allocation algorithm, the proposed algorithm make a bandwidth allocation more efficient. As for the QoS, it has been shown that proposed algorithm shows better performance than that with static bandwidth allocation algorithm.

건강한 성인에서 발병한 칸디다와 연관된 위궤양 1례

박지훈,이상혁,김희,이재호,박성재,지삼룡,양성연,박은택,이연재,설상영,정정명,강미선 白中央醫療院 2005 仁濟醫學 Vol.26 No.1

Fungus such as Candida albicans is a normal flora that is frequently found in the oral cavity, gastrointestinal tract, genitourinary tract, vaginal mucosa in a normal person. However, candida can cause opportunistic infection in an immune compromised host. Candidiasis has broad spectrum of disease from mucocutaneous infection to invasive or disseminated infection. But, it is rarely reported that candida is associaed with gastrointestinal tract disease in a healthy adult. The case of gastric ulcer associated with candida particularly in a health adult is reported with relevant literature.

울산 석유화학공단 인근 어린이들의 혈액상변화 및 면역기능

이충렬,유철인,이지호,이헌,김양호 대한산업의학회 2001 대한직업환경의학회지 Vol.13 No.2

목적 : 지역 특성상 휘발성 유기화합물, 분진, 악취 등 환경오염의 영향을 많이 받는 것으로 추정되는 울산석유화학공단 인근 어린이들의 혈액상 변화, 계절 차이에 의한 혈액상 변화와 면역기능에 미치는 영향을 평가하기 위하여 본 연구를 실시하였다. 방법 : 2000년 4월, 7월, 10월 3회에 걸쳐 석유화학공단 인근 A 초등학생 46명(남자 32명, 여자 14명), B 초등학생 97명(남자 49명, 여자 48명)과 교외지역의 A 초등학생 95명(남자 47명, 여자 48명)을 대상으로 일반혈액검사, 백혈구 백분율 검사를 실시하였으며 7월 조사 때는 B 및 C 초등학생 11세 남자 각각 25명을 대상으로 면역학적 기능검사를 실시하였다. 결과 : 3차례에 걸쳐 진행된 검사결과는 계절별로 다른 양상을 보여 주었다. 즉, 총백혈구수, 호중구수, 림프구수는 A와 C 초등학생은 7월 조사에서는 감소되었다 다시 10월 조사 때는 다시 증가하는 경향을 보여주며, B초등학생은 계절별 변화가 거의 없는 것으로 나타났다. 적혈구수는 B와 C 초등학생은 7월 조사시 감소되었다가 10월 조사 때는 다시 증가하는 양상을 보여주나 A 초등학생은 갈수록 감소하는 경향을 보여주었다. 혈색소량의 변화는 적혈구수의 변화와 유사하였다 혈소판수는 모두 7월 조사 때는 감 소되었다가 10월 조사 때는 다시 증가하는 양상을 보여주었다. 조사시기에 따라 각 학교 어린이들간에 혈구세포수의 차이가 있음을 구명하기 위하여 generalized linear model의 repeated measures ANOVA를 시도한 결과 연령과 성을 공변인으로 보정한 후의 P 값에서 조사시기의 차이와 학교간 차이의 교호작용변수(interaction variable)는 모든 혈구세포에서 유의한 것으로 나타났다(P<0.05). 이는 조사시기에 따라 각 학교어린이들간에 혈구세포수의 차이가 유의하게 다르다는 것을 의미한다. 면역기능 평가를 위하여 혈중 immunoglobulin 측정 및 림프구 아형 분포분석을 B 및 C 초등학생 6학년 남학생 각 25명, 총 50명을 대상으로 실시하였으나 모두 정상범위이었고 학교간 차이도 없었다. 결론 : 휘발성 유기화합물 같은 물질에 쉽게 영향을 받을 수 있는 백혈구와 적혈구 등의 혈구세포는 조사시기에 따라 각 학교어린이들간에 혈구세포수의 차이가 유의하게 나타남은 각 학교 어린이들간에 조사시기에 따라 혈구세포수에 영향을 주는 휘발성 유기화합물의 노출량의 차이가 중요한 원인 중 하나일 것으로 추정된다. 향후 혈구세포의 변화의 원인이라 추정되는 휘발성 유기화합물의 기중 농도측정이나 체내 생체지표검사를 통한 노출원 조사를 병행하는 추가적 조사가 필요한 것으로 사료된다. Objectives : To evaluate the hematological changes and the immunological function of children living near the petrochemical estate in Ulsan. Methods : The study subjects comprised of 238 children who consisted of 143 children living near the petrochemical estate and 95 children living in a suburban area. We conducted the hematological examination 3 times, in April, July and October. Also we evaluated the immunological function of some children in July. To confirm differences between schools repeated measures ANOVA of generalized linear model was done controlling age and sex as covariates. Results : The blood cell counts of children showed differences between schools in accordance with the survey month. The total WBC, neutrophil, and lymphocyte counts of children living in a suburban area decreased in July and increased in October again, but those of some children living near the petrochemical estate did not changed distinctly. The RBC counts of children living in a suburban area decreased in July and increased in October again, but those of some children living near the petrochemical estate decreased as time passed. The changes of the amount of hemoglobin of all study subjects were similar with those of RBC. The platelet counts of all study subjects decreased in July and increased in October again. In the generalized linear model, school was a significant independent variable for the total WBC, RBC, and platelet counts, and sex was a significant independent variable for the RBC counts. Age was a significant independent variable for the iymphocyte and platelet counts. P values of all blood cell were statistically significant in interaction variable between the survey month and school, and those of the total WBC, neutrophil, and iymphocyte counts were statistically significant in interaction variable between the survey month and age. The immunological function showed no significant difference between study groups. Conclusions : The total WBC and RBC counts which would be easily affected by volatile organic compounds (VOCs) in the atmosphere showed differences between schools in accordance with the survey month. This suggests that the amounts of exposure to VOCs are different among each school children in different months. To ascertain the hematological changes by VOCs, an additional study evaluating the concentrations of atmosphere of VOCs and biological monitoring of some VOCs is needed.

부산, 울산, 경남지역 직업병감시체계에서 나타난 수지진동증후근의 역학적 특성

최영희,유철인,이지호,이충렬,이헌,김영욱,채창호,고상백,김은아,이유진,김양호 大韓産業醫學會 2003 대한직업환경의학회지 Vol.15 No.3

목적: 국내에서도 국소진동에 의한 수지진동증후군이 다수 있을 것으로 추정하나 최근에 이에 대한 보고가 적어 부·울·경 직업병감시체계를 통하여 수지진동증후군에 대한 환례를 수집하여 이의 역학적 특성을 밝히고자 본 연구를 실시하였다. 방법: 2001년 44월부터 2002년 12월까지 부산, 울산, 경남지역에 있는 종합병원 9곳을 통하여 특수 건강진단과 산업의학과 외래를 방문한 근로자를 대상으로 진동폭로에 대한 설문조사를 실시하고 이들중에서 수지진동으로 인한 증상을 호소하는 근로자는 이학적 검사와 Stockholm workshop scale을 이용하여 수지진동증후군이 있는지 평가하였다. 결과: 남자 188명, 여자 4명 등 총 192례의 수진진동증후군이 의심되는 환례를 수집하였으며, 업종별로는 조선업에 종사하는 근로자들이 가장 많았다. 국소진동의 주된 폭로원은 그라인더가 가장 많았으며, 혈관장해로 인한 증상보다 감각신경성 장해로 인한 증상을 많이 호소하였다. 결론: 전국적으로 조선업종의 그라인더 사용자를 중심으로 많은 수의 수지진동증후군의 환자가 있을 것으로 추정되며, 이들에 대한 예방대책을 마련하기 위하여 전국규모의 정확한 유병률 조사 및 실태파악이 필요한 것으로 판단된다. Objects: The objectives of this study were to estimate the epidemiologic characteristics of hand-arm vibration syndrome (HAVS) due to occupational exposure of hand transmitted vibration and to identify the occupations and industries where such exposures arises, and the main sources of exposure. Methods: In April 2001 the Busan, Ulsan, and Kyung-Nam Province occupational disease surveillance system was established to measure the incidence and prevalence of work-relatd HAVS and other occipational diseases in these Korean provinces. Occupational physicians of nine hospitals in Busan, Ulsan, and Kyung-nam Province were involved in this project between April 2001 and November 2002. Physicians collected information through questionnaires and interviews. Information gathered included age, occupation, types of vibration tools used and presence of subkective symptoms such as vibration-induced white finger (VWF), numbness and tingling. Results: A total 192 cases were reported with 188 males and 4 females. The shipbuilding industry was the most common type of industry and grinders were the most common source of exposire. Symptoms of neurological disorder were more common than those of vascular disprder. Conclusions: The authors concluded that exposure to hand transmitted vibration is common and that HAVS is one of the most common occupational diseases in Korea. However, the range and extent of hand transmitted vibration and the overall prevalence of HAVS in Korea is still unknown. More extensive research on this syndrome in order to priorite necessary preventive measures is required.

Enhanced inflammation with disturbed epidermal restoration during atrophic acne scar formation

( Ji Hoon Yang ),( Jungyoon Moon ),( Ji Young Yoon ),( Seonguk Min ),( Hyuck Hoon Kwon ),( Dae Hun Suh ) 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2

Background: Atrophic acne scar can cause cosmetic as well as psychosocial problems, thereby significantly reducing the patient’s quality of life. However, its detailed pathogenesis has not been revealed yet. Objectives: This study was conducted to understand the pathogenesis of atrophic acne scar with regard to inflammation and keratinocyte proliferation. Methods: Thirty subjects who have active acne or acne scar were included. The subjects were divided into two groups; fifteen were prone to acne scar (APS) and the others were not prone to acne scar (ANS). Skin samples of acne lesions were obtained on day 1, 3 and 7 after their onset, and the difference of several molecular profiles between two groups was examined. Results: Expression of CD4, CD45RO and HLA-DR which represent T helper cells, memory T cells and antigen presenting cells respectively, were gradually increased in APS compared to ANS in a time-dependent manner. Production of proinflammatory cytokines such as TNF-α, IL-1α, IL-1β, IL-2, IL-6, IFN-γ, VCAM1 and VEGF were also increased in APS. However, level of IL-10 was considerably lower in APS than that in ANS. With regard to epidermal restoration, c-Myc and p-ERK, molecules associated with cell cycle progression, was significantly reduced in APS. On the contrary, p21, which prevents cellular growth, was increased in APS. Conclusion: Significantly amplified inflammation with reduced epidermal proliferation in acne lesions may result in atrophic acne scar formation.

A Clinical Study of 39 Cases of Malignant Germ Cell Tumors of the Ovary

( Ji Yang Park ),( Young Oak Lew ),( Yong Hun Chee ),( Do Kang Kim ),( Dae Hoon Kim ),( Seung Eun Namkoong ),( Hun Young Lee ) 대한산부인과학회 1992 대한산부인과학회 학술대회 Vol.69 No.-

Inhibition of LPS-Induced NO, TNF-α, and PGE2 Production in Mouse Marcrophage by Extract Mixtures from Hericium Erinaceus, Kalopanacis Cortex and Astragalus Membranaceus

Ji-Hun SeoMoon,Yang-Ji Kim,Su-Young Hong,Oh-Kyung Kwon 한국식품영양과학회 2015 한국식품영양과학회 학술대회발표집 Vol.2015 No.8