CDMA 휴대전화기용 IF 표면탄성파 필터의 설계 및 제작

양형국,조현민,박종철 대한전자공학회 1998 電子工學會論文誌, D Vol.d35 No.4

Remez exchange algorithm was applied to realize an IF SAW filter for CDMA cellular phone systems. A SAW filter with withdrawal weighted transducers was simulated and then fabricated on 42.75.deg. ST-cut Quaritz wafer. Excellent agreement wasobtained between calculated andmeasured responses. Fabricated SAWfilterswere mounted on ceramic SMD package for reducing their size and volume. SAW filters were measured under matched circuit. As a result, 5 dB bandwidth of 1.32 MHz, 33dB bandwidth of 1.76 MHz, insertion loss of 13.8 dB and peak to peak ripple at passband of 0.26 dB were obtained. Linear group delay responses at passband were also obtained. These characteristics were good for practical use of IF SAW filter for CDMA system.

일차의료에서 인공지능의 활용

양형국 대한가정의학회 2023 Korean Journal of Family Practice Vol.13 No.2

In recent years, artificial intelligence (AI) has become ubiquitous in our lives and is increasingly being used in healthcare, with applications in image analysis, disease prediction, drug development, and personalized care. In primary care, which is characterized by accessibility, comprehensiveness, coordination, prevention, and continuity, AI can enhance the delivery of healthcare, improve access to patient care, and enable personalized care. However, before AI can be utilized, it is necessary to understand the insufficient evidence-based research in real-world clinical settings, the ambiguity of the mechanisms of action represented by the black box, and the assessment of the benefits and risks of utilizing the analytical results of AI medical devices.

표면탄성파 필터를 이용한 800 MHz 대역용 듀플렉서 제작 ( Fabrication of 800 MHz Band Duplexer Using SAW Filters )

양형국,조현민,박종철 대한전자공학회 1998 대한전자공학회 학술대회 Vol.1998 No.7

Regional Factors Associated with Participation in the National Health Screening Program: A Multilevel Analysis Using National Data

양형국,신동욱,황승식,오주환,조비룡 대한의학회 2013 Journal of Korean medical science Vol.28 No.3

High participation rates are important for maximizing the effects of a health screening program. Previous studies have suggested that individual or regional characteristics have effects on health behaviors. In this study, we investigated the determinants of participation in the National Screening Program for Transitional Ages by simultaneously analyzing individual and area-level factors by multilevel analysis. A total of 1,081,216 subjects, aged 40 and 66 yr and nested in 254 areas, were included. There was a significant variation in participation rates across the areas even after adjusting for individual and area-level variables. Among the individual-level variables, increasing age, sex, higher income, and mild disability grade were associated with a higher participation rate. In urban areas, the 40-yr-old group had higher participation rates than the 66-yr-old group. Deprived areas had significantly high participation rates for both age groups. The number of screening centers per 1,000 inhabitants had no significant effect on participation in the screening program. In conclusion, regional characteristics are associated with participation rates independent of personal features and regional factors have differential effects with respect to age. A multi-dimensional approach is recommended to promote participation in health screening programs.

표면탄성파 필터를 이용한 800 ㎒ 대역용 듀플렉서 제작

양형국(Hyung Kook Yang),조현민(Hyun Min Cho),박종철(Jong Chul Park) 대한전자공학회 1998 대한전자공학회 학술대회 Vol.1998 No.6

데페록사민 전처치가 토끼 심근경색 크기의 감소에 미치는 효과

양관모,오동렬,박승현,박규남,이원재,김형국,황두영,최승필,채장성 대한응급의학회 1998 대한응급의학회지 Vol.9 No.4

Background: Reperfusion of ischemic myocardium has been postulated to result in a specific oxygen radical mediated tissue injury. Iron may liberate during ischemia and we hypothesized that administration of the iron chelator, deferoxamine during ischemia would result in improved recovery after postischemic reperfusion. Purpose: To test whether iron-catalyzed processes contribute to myocardial necrosis during ischemia and reperfusion, deferoxamine was administered to block iron catalyzed hydroxyl radical formation in rabbits. Methods: Eleven rabbits were divided into two groups : control group (n=5) and deferoxamine pretreatment group (n=6). The left circumflex coronay artery was ligated for 30 minutes and reperfused for 180 minutes. Area at risk (AR) was measured by non-stained area with methylene blue injection into left atrium after left circumflex coronary artery ligation. Infarct size was measured by weighing after triphenyltetrazolium chloride staining. Heart rate was measured using electrocardiographic recording and systemic blood pressure was monitored by pressure transducer connected to the catheter in the left ventricle. Results: 1. There was no significant difference of heart rate and blood pressure in deferoxamine pretreatment group compared with control group. 2. There was significant decrease of serum iron concentration after continuous infusion of deferoxamine compared with serum iron concentration before ligation of coronary artery(P<0.05). 3. There was no significant difference of area at risk between control and deferoxamine pretreatment group. 4. Area at necrosis to area at risk was significantly reduced in deferoxamine pretreatment group compared with control group(P<0.05). The results suggest that deferoxamine infusion prior to coronary artery occlusion has a significant benefit in reducing infarct size in this model.

유기용제 흡입중독후 의식소실로 발생한 중증의 저체온증 치유 1례

양관모 ( Kwan Mo Yang ),권태욱 ( Tae Wook Kwon ),김형국 ( Hyung Kook Kim ),박규남 ( Kyu Nam Park ),김세경 ( Se Kyeung Kim ) 대한응급의학회 1997 대한응급의학회지 Vol.8 No.2

A 19-year-old man had a good neurologic recovery from a severe hypothermia(19C) and a prolonged coma following active intemal rewarming. From inhaling hydrocarbons, he was left unconscious on the cold floor for 24 hours. As soon as the patient was brought into the emergency medical center, he was early evaluated and treated aggressively. 'ECG showed Osborn(J) wave on all leads. The temperature of patient was increased by 2-3C per hour through active external rewarming (by heating blankets and warm bag) and active intemal rewarming (by airway rewarming, warmed IV fluids, gastrointestinal tract irrigation, and bladder irrigation). The temperature reached 36C after 6 hours. Active internal rewarming provides rapid core rewarming with the additional benefit of circulatory support during the period of cardiac instability.

Nitrous Oxide 농도에 따른 진통효과와 혈역학적 변화에 대한 비교 관찰

이운정,김형국,양관모,유은영,나병호,이원재,박규남,권태욱,김세경 대한응급의학회 1997 대한응급의학회지 Vol.8 No.4

Background: Nitrous oxide is a safe analgesics which has analgesic and sedative effects without loss of consciousness. The advantage of Nitrous oxide is that it has a rapid onset time and that we can modulate duration of its action. The purpose of this experiment is to obtain the safe and effective concentration of Nitrous oxide in Emergency Department as use of analgesics and sedative drugs. Methods: Twenty volunteers were investigated according to double blind method Nitrous oxide was administrated to volunteer subjects at different concentrations ; 33%, 50%, 67% each. Then we evaluated the Pain score, Blood pressure, Heart rate, Respiratory rate, Oxygen saturation and its side effects. Results: Pain Score were 8.4 ±2.1 at 33% 6.1 ±1.5 at 50% and 3.65 ±2.2 at 67% of Nitrous oxide. Pain Score is decreased significantly following administration of Nitrous oxide at concentration of 50%, 67%(p<0.05). There was no difference between preadministration group and postadministration group. While no remarkable change in systolic blood pressure, heart rate, and oxygen saturation. Respiratory rate showed significant increase when 67% of Nitrous oxide was administrated. There was no side effect in administration of 33% of Nitrous oxide. When 50% of Nitrous oxide was administrated, there were dizziness 5(25%), paresthesia 2(10%), nausea 1(5%), palpitation 1(5%), and hyperethesia 1(5%). At 67% of Nitrous oxide, there were nausea 7(35%), dizziness 6(30%), paresthesia 5(25%), headache 5(25%), diplopia 2(10%), dysphoria 2(10%), salivation 1(5%), dyspnea 1(5%), nystagmus 1(5%), tinnitus 1(5%) and euphoria 1(5%). Incidence of side effect increased as the concentration of Nitrous oxide was increased. Conclusion: We can conclude that safe and effective concentration of Nitrous oxide is 50% as analgesics and sedative drugs in the emergency department.

유기용제 흡입중독후 의식소실로 발생한 중증의 저체온증 치유 1례

박규남,김형국,양관모,권태욱,김세경 대한응급의학회 1997 대한응급의학회지 Vol.8 No.2

A 19-year-old man had a good neurologic recovery from a severe hypothermia(19℃) and a prolonged coma following active internal rewarming. From inhaling hydrocarbons, he was left unconscious on the cold floor for 24 hours. As soon as the patient was brought into the emergency medical center, he was early evaluated and treated aggressively. ECG showed Osborn(J) wave on all leads. The temperature of patient was increased by 2-3℃ per hour through active external rewarming (by heating blankets and warm bag) and active internal rewarming (by airway rewarming, warmed IV fluids, gastrointestinal tract irrigation, and bladder irrigation). The temperature reached 36℃ after 6 hours. Active internal rewarming provides rapid core rewarming with the additional benefit of circulatory support during the period of cardiac instability.

Supporting Low-Income Cancer Patients: Recommendations for the Public Financial Aid Program in the Republic of Korea

민혜숙,양형국,박기호 대한암학회 2018 Cancer Research and Treatment Vol.50 No.4

Purpose As the recent term of “financial toxicity” implies, cancer causes a treatment-related financial harm. Financial Aid Program for Cancer Patient (FAPCP) is a government’s financial support for low-income patients in the Republic of Korea. This study aimed to describe FAPCP applicants’ condition and to investigate factors influencing financial burden, which would provide the basis for implementing a strategy for FAPCP administration. Materials and Methods The telephone survey results from 2,700 FAPCP participants were analyzed, including demographic, socioeconomic, and disease characteristics and experiences associated with financial burden and the actions or measures to cope with them. Results Overall, 87.6% experienced financial burden more than moderate degree, 39.2% got financial help/a loan, 17.8% disposed of their property, and 10.2% changed or stopped treatment owing to medical costs. Monthly household income was connected to financial burden, and the highest income group was associated with the lowest financial burden (odds ratio [OR], 0.21; 95% confidence interval [CI], 0.11 to 0.38) and the lowest rate of changing/stopping care (OR, 0.23; 95% CI, 0.05 to 1.00). Parents of childhood cancer patients got financial help/a loan (OR, 2.24; 95% CI, 1.03 to 4.88) and disposed of their property (OR, 3.18; 95% CI, 1.40 to 7.22) more frequently, and Medical Aids applicants showed the highest rate of changing/stopping care (OR, 3.01; 95% CI, 1.89 to 4.78). Conclusion FAPCP targets low income groups; however, financial burden and the consequent actions taken still exist disproportionately, depending on the income of the applicants. FAPCP should focus on more vulnerable groups including Medical Aid applicants and parents of childhood cancer patients, by increasing funds and expanding their support coverage.