Analysis of Schottky Barrier Height in Small Contacts Using a Thermionic-Field Emission Model

장문규,JunghwanLee 한국전자통신연구원 2002 ETRI Journal Vol.24 No.6

This paper reports on estimating the Schottky barrier height of small contacts using a thermionic-field emission model. Our results indicate that the logarithmic plot of the current as a function of bias voltage across the Schottky diode gives a linear relationship, while the plot as a function of the total applied voltage across a metal-silicon contact gives a parabolic relationship. The Schottky barrier height is extracted from the slope of the linear line resulting from the logarithmic plot of current versus bias voltage across the Schottky diode. The result reveals that the barrier height decreases from 0.6 eV to 0.49 eV when the thickness of the barrier metal is increased from 500 Å to 900 Å. The extracted impurity concentration at the contact interface changes slightly with different Ti thicknesses with its maximum value at about 2.9×1020 cm-3, which agrees well with the results from secondary ion mass spectroscopy (SIMS) measurements.

운동생리학 : 중년남성 고혈압자의 체지방률 차이가 운동부하검사시 심혈관계에 미치는 영향

김석희(SeokHeeKim),김정환(JungHwanLee),이창호(ChangHoLee) 한국체육학회 2003 한국체육학회지 Vol.42 No.3

The subjects of this research were 35 males with hypertension in ages 40 to 59, who do not exercise regularly with 140mmHg or higher SBP (Systolic Blood Pressure) or 90mmHg or higher DBP (Diastolic Blood Pressure). The subjects were divided into Group 1 and 2 Group 1 was composed of 17 patients with less than 20 % body fat. Group 2 was composed of 18 patients with higher than 20 % body fat. We have conducted incremental treadmill exercise testing (prior to exercising, maximum, and recovering phases) on both groups and analyzed the heart rate, blood pressure, myocardial oxygen uptake and maximal oxygen consumption among the elements of cardiovascular system. The results are as follows. 1) Changes in Heart Rate: When the patients were relaxed, there was a significant difference in the heart rate in Group 2 (% Body fat>20%) (p<.05). 2) Change in Blood Pressure: In terms of the SBP, there were significant differences in the maximum phase and recovery 1, 2, 4 and 5 phases in Group 2 (%Body fat>20%) (p<.05). Group 2 showed rather high level of change during the resting and recovering 3 phase; however, there was no significant difference. In terms of the DBP, Group 2 (% Body fat>20%) showed rather high level of change in all phases excluding the recovery 1 phase. However, there was no significant difference. 3) Change in Myocardial Oxygen Uptake: Group 2 (% Body fat>20%) showed significant differences in myocardial oxygen uptake in the maximum phase, recovery 1, 2, 4 and 5 phases (p<.05). There was a rather high level of change also in the resting and recovery 3 phases; however there was no significant difference. 4) Maximal Oxygen Consumption: Group 2 (% Body fat>20%) showed rather high level of maximal oxygen consumption; however, there was no significant difference. In conclusion, in case of middle aged men with hypertension, with high percent body fat, high result was shown in the recovery phase with rapid rise in maximal SBP. The same result was also shown in myocardial oxygen uptake. As so, when a patient with hypertension and with high percent body fat exercises, compared to those with low percent body fat, danger elements of cardiovascular system disorder such as heart attack and hematencephalon will increase along with rise in the heart pressure. In case of conducting the exercise prescription, minute caution is necessary.

Systematic Review and Meta-Analysis of Immune Response of Increased Dose of Hepatitis B Vaccination in HIV-Infected Patients

( Jung Hwan Lee ),( Jae Hyoung Im ),( Jin-soo Lee ),( Ji Hyeon Baek ),( Jung Hwan Yu ),( Young-joo Jin ),( Jin Woo Lee ),( Hea Yoon Kwon ) 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: The prevalence of co-infection of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) is high and increases risk of hepatitis B chronicity and mortality. Despite guidelines for HIV-infected patients to be immunized against HBV, the immunogenicity of the HBV vaccination in HIV-infected patients is lower than that in the HIV-seronegative population. Methods: In this study, we performed a systematic review of the literature and meta-analysis of randomized clinical trials to investigate the response rate to an increased dose of HBV vaccination in HIV-infected patients. A fixed-effects model, with heterogeneity and sensitivity analyses, was used. We identified nine studies involving 970 HIV-positive vaccine recipients. Results: The study results were divided into two groups, depending on the time when antibody against hepatitis surface antigen was measured. Results showed a significant increase in response rates among patients who received a double dose of the vaccine versus the standard dose in both subgroups; the pooled odds ratio (OR) was 1.76 (95% confidence interval [CI]: 1.36-2.29) and 2.28 (95% CI: 1.73-3.01) for the rate that was measured 4-6 weeks and >12 months after completion of vaccination, respectively. The total OR was 1.99 (95% CI: 1.64-2.41). No heterogeneity was found. Conclusions: Our meta-analysis shows that a double dose of the HBV vaccine may significantly improve the immune response in HIV-infected patients. Higher immunogenicity was observed, when it was measured 4-6 weeks and >12 months after completion of the vaccination.

Value Assessment for Inland Wetlands according to Ecological Geographic Distribution

Jung-Hwan Lee,Ran-Young Im,Gwan-Gyu Lee,Hyun-Chul Park 한국습지학회 2016 한국습지학회지 Vol.18 No.4

한국은 2000년부터 2010년까지 전국을 조사하여 총 1,916개소의 내륙습지 인벤토리를 구축한 바 있다. 본 연구는 국가보 호지역과 내륙습지와의 입지상관관계를 분석함으로써 내륙습지의 관리가치 측면을 평가하고자 하였다. 그 결과, 내륙습지 의 상당수가 자연환경의 보호가치가 높아 국가가 보호지역으로 지정하여 관리하는 지역 내에 입지(527개소, 31.61%)하고 있는 것으로 나타났다. 보호지역 반경 1km 까지 범위를 넓혀 보면 959개소로 전체 국가내륙습지의 57.53%에 해당하는 수가 보호지역 내 및 인근에 입지하고 있음을 알 수 있다. 그 중에서도 하천수계 반경 1km 내에 46.79%가 분포하여 보호 지역 내 분포하는 습지 중 81.33%를 기록하고 있어서 현재의 내륙습지의 입지는 대부분 하천수계에 접하여 있는 것으로 분석되었다. 각종 보호지역과의 이격거리를 분석하여 중첩 분석한 결과를 상, 중, 하로 평점구분하고 내륙습지와의 입지관 계를 분석한 결과, 보호가치가 ‘상’인 지역에 분포한 습지의 개소가 998(59.87%)에 해당하였다. 보호가치가 ‘하’인 지역에 도 289개소(17.34%)가 분포되어 있는데, 이는 인공화된 지역에 입지한 습지로써 환경압력에 더욱 노출되어 있는 습지임 을 의미하므로 훼손방지를 위한 대책수립을 고려해야 할 내륙습지로 의사결정할 수 있다. Korea established an inventory of 1,916 sites of inland wetlands during a nationwide investigation from 2000 to 2010. If inland wetlands is included in or near various protected areas designated by the government, it can be selected as a wetland to be managed with priority. This study evaluated the aspect of management of inland wetlands by analyzing the correlation between locations of national protected areas and inland wetlands. As a result, it was shown that a considerable percentage of current inland wetland was located in areas that were designated and managed as protected areas by the government, as they had a high value of natural environment protection (527 sites, 31.61 %). When the range was widened to a radius of 1 km for protected areas, 959 sites were included and 57.53 % of sites were located in or nearby the protected areas. Among them, 46.79 % of sites were distributed up to or within a 1 km radius of waterside areas and rivers; it accounted for 81.33 % of wetlands located in protected areas. Therefore, it was found that locations of current inland wetlands were mostly in contact with rivers. The results of overlay analysis were classified into high, medium and low; the correlation of location with inland wetlands was analyzed through the analysis of separation distance of various protected areas. The number of wetlands located in areas of a ‘high’ value of protection was 998 (59.87 %); 289 sites (17.34 %) were distributed in areas of a ‘low’ value of protection. This implies that these wetlands are located in artificial areas and are more exposed to environmental pressures. Thus, these wetlands could be determined as inland wetlands, which we considered for the establishment of measures to prevent damage.

Gastrocolocutaneous Fistula: An Unusual Case of Gastrostomy Tube Malfunction with Diarrhea

Junghwan Lee,Jinyoung Kim,Ha il Kim,Chung Ryul Oh,Sungim Choi,Soomin Noh,나희경,Hwoon-Yong Jung 대한소화기내시경학회 2018 Clinical Endoscopy Vol.51 No.2

A gastrocolocutaneous fistula is a rare complication of percutaneous endoscopic gastrostomy (PEG). We report a case of agastrocolocutaneous fistula presenting with intractable diarrhea and gastrostomy tube malfunction. A 62-year-old woman with ahistory of multiple system atrophy was referred to us because of PEG tube malfunction. Twenty days prior to presentation, the patientstarted developing sudden diarrhea within minutes after starting PEG feeding. Fluoroscopy revealed that the balloon of the PEG tubewas located in the lumen of the transverse colon with the contrast material filling the colon. Subsequently, the PEG tube was removedand the opening of the gastric site was endoscopically closed using hemoclips. Clinicians should be aware of gastrocolocutaneousfistula as one of the complications of PEG insertion. Sudden onset of diarrhea, immediately after PEG feedings, might suggest thiscomplication, which can be effectively treated with endoscopic closure.

Isolation of Shared Resources for Mixed-Criticality AUTOSAR Applications

Junghwan Lee,Myungjun Kim 한국정보과학회 2022 Journal of Computing Science and Engineering Vol.16 No.3

Temporal isolation without consideration of spatial isolation has been attained for mixed-criticality systems, while the need for spatial isolation is urgently required in the automotive industry. Moreover, tasks with different criticality levels sharing the same resources are a common requirement for safety-critical automotive applications. Such tasks are more challenging to spatially isolate due to context sharing to access the same resources. Nevertheless, safety certification cannot be issued without addressing spatial isolation. This paper argues that traditional real-time locking solutions are unsuitable for mixed-criticality applications within the automotive open system architecture (AUTOSAR). We adopted the server task named resource server for spatial isolation within AUTOSAR limitations. We formalized a software component model for reducing design space and proposed the mapping algorithms. Properties of resource servers within AUTOSAR were formally analyzed for blocking delays, task priority assignment, and utilization analysis. Case studies in a powertrain domain of an electric vehicle were carried out to assess the proposed solutions.

End-to-end Convolutional Neural Network Design for Automatic Detection of Influenza Virus

Junghwan Lee,Heesang Eom,Yuli Sun Hariyani,Cheonjung Kim,Yongkyoung Yoo,Jeonghoon Lee,Cheolsoo Park 대한전자공학회 2021 IEIE Transactions on Smart Processing & Computing Vol.10 No.1

Owing to the high mortality rate of influenza diseases, the early examination and accurate detection of the influenza virus are crucial for preventing potential tragedies. This paper reports the design of a highly reliable machine learning classifier for automatic detection of the influenza virus based on an image of its detection kit. Convolutional neural networks (CNNs), currently the most reliable image classifiers, were designed for the images of an influenza detection kit, and their hyperparameters were fine-tuned using an architecture search algorithm, Bayesian optimization, and hyperband (BOHB). With an overall accuracy of 90.14%, the designed and optimized 2DCNNs algorithm successfully separate the influenza virus from normal using the detection kit images.

Controlled release behavior and characterization of ropinirole hydrochloride using multi-layer formulation

Jung Hwan Lee,Jeawon Yang,Jin Young Park,Cheon Jung Lee,Na Keum Jang,Jae Hoon Shin,이동원,강길선 한국약제학회 2015 Journal of Pharmaceutical Investigation Vol.45 No.2

In this paper, we report cost-effective andsimply achievable extended release formulations of ropinirolehydrochloride (RP) by forming coating layers withwell-known polymers. The upper and bottom coating layerswere composed of one of gel-forming polymers such asPEG, PVP, and HPMC, respectively, designed to controldrug release profile. The core tablet is prepared by wetgranulation method with RP and HPMC (150 K). Themulti-layer tablet showed much slower release behaviorthan that of commercially available once-diary formulation(REQUIP PDⓇ, 4 mg, GSK) in the pH 1.2 conditionsregardless of coated polymers, and zero order releaseprofiles of RP were observed in the pH 6.8 dissolutionconditions, which is nearly identical to dissolution profileof REQUIP PDⓇ. These results indicate that the formationof multi-layer tablet is one of promising strategies forextended release formulation of RP, in addition, betterbioavailability is expected due to minimized dissolutionprofiles of RP in low pH.

Bioactive nanoparticles for dental application

Jung-Hwan Lee 대한치과재료학회 2018 대한치과기재학회 학술대회 Vol.2018 No.4

Synthesis and Properties of Oligomers Containing 3-Triethylsilyl-1-silacyclopent-3-ene and Borane Derivatives via Polyaddition Reaction

Jung Hwan Lee,Young Tae Park* 대한화학회 2004 Bulletin of the Korean Chemical Society Vol.25 No.6