Characteristic enhancement of white LED lamp using low temperature co-fired ceramic-chip on board package

Sim, J.K.,Ashok, K.,Ra, Y.H.,Im, H.C.,Baek, B.J.,Lee, C.R. Elsevier 2012 CURRENT APPLIED PHYSICS Vol.12 No.2

In this paper, we propose low temperature co-fired ceramic-chip on board (LTCC-COB) package with improved thermal characteristics; no insulation layer exists between the LED chip and metal base. In actual measurement as well as in thermal simulation, the proposed LED lamp structure showed excellent thermal properties, compared with surface mound device-printed circuit board (SMD-PCB) package LED lamp. The optical output power, thermal distribution, current-voltage (I-V) and electroluminescence (EL) were measured and compared to analyze the characteristics of LTCC-COB package LED lamp with SMD-PCB package LED lamp. EL peak intensity of LTCC-COB package LED lamp is 1.75 times better than that of SDM-PCB package LED lamp. The thermal resistance between packing area and air was found to be 7.3 K/W and 7.9 K/W for LTCC-COB package and SMD-PCB package respectively. The proposed LTCC-COB packaged LED lamp is not only suitable for high power LED package due to its low thermal resistance but also a promising solution for illumination modules.

Evaluation of ethanol production and bioadsorption of heavy metals by various red seaweeds

Sunwoo, I. Y.,Ra, C. H.,Jeong, G. T.,Kim, S. K. Springer Science + Business Media 2016 BIOPROCESS AND BIOSYSTEMS ENGINEERING Vol.39 No.6

<P>The objective of this study was to evaluate ethanol production and bioadsorption with four red sea-weeds, Gelidium amansii, Gracilaria verrucosa, Kappaphycus alvarezii and Eucheuma denticulatum. To produce ethanol, thermal acid hydrolysis, enzymatic saccharification and fermentation was carried out. After pretreatment, 38.5, 39.9, 31.0 and 27.5 g/L of monosaccharides were obtained from G. amansii, G. verrucosa, K. alvarezii and E. denticulatum, respectively. Ethanol fermentation was performed with Saccharomyces cerevisiae KCCM 1129 adapted to 80 g/L galactose. The ethanol productions by G. amansii, G. verrucosa, K. alvarezii and E. denticulatum were 18.8 g/L with Y-EtOH = 0.49, 19.1 g/L with Y-EtOH = 0.48, 14.5 g/L with Y-EtOH = 0.47 and 13.0 g/L with Y-EtOH = 0.47, respectively. The waste seaweed slurries after the ethanol fermentation were reused to adsorb Cd(II), Pb(II) and Cu(II). Using langmuir isotherm model, Cu(II) had the highest affinity for waste seaweeds with the highest qmax and electronegativity values among three heavy metals.</P>

주의력결핍 과잉행동장애 남아의 증상과 부모의 주의력결핍 과잉행동 증상 및 인격 양상과의 관련성

신승우(Woo-Seung Shin),최혜라(Hye-Ra Choi),김건우(Kynwoo Kim),이중선(Joong-Sun Lee),박수빈(Subin Park),홍진표(Jin Pyo Hong),유한익(Hanik K. Yoo) 대한소아청소년정신의학회 2009 소아청소년정신의학 Vol.20 No.1

Objectives : This study was conducted to investigate the association between the symptoms of boys with attention-deficit hyperactivity disorder (ADHD) and the attention-deficit hyperactivity symptoms, temperament and character patterns of their parents. Methods : Forty-five boys with ADHD and who met the DSM-IV criteria were evaluated by using the ADHD rating scale (ADHD-RS), and their parents completed the Korean Adult ADHD scale (K-AADHDS) and the Temperament and Character Inventory (TCI). Results : The parental K-AADHDS scores were not associated with the ADHD-RS total score and the subscale scores of their siblings. The most potent variable related to the ADHD-RS total score was the maternal self-directedness, and the second was the maternal persistence. The maternal self-directedness was the variable that was most correlated with the hyperactivity/impulsivity subscale scores of the ADHD-RS. Conclusion : The results suggest that the paternal ADHD symptoms may not be related to the ADHD symptoms of boys with ADHD. Higher maternal self-directedness and persistence may decrease overall the ADHD symptoms of these boys, and higher maternal self-directedness itself may predict lower hyperactivity/impulsivity symptoms of the boys with ADHD.

용접기용 전원장치의 도전손실 저감에 관한 연구

라병훈,고강훈,박성우,김준홍,이현우 경남대학교 신소재연구소 1998 論文集 Vol.10 No.-

본 논문은 용접기용 전원장치의 도전손실 저감에 관하여 제안하고 있다. 최근, 산업용 기기의 전원장치에 많이 적용되고 있는 소프트 스위칭 방식에는 모두가 일장일단이 있다. 대용량의 용접기용 전원장치로 주로 사용되는 기존의 Phsae-Shifted FB DC-DC 컨버터는 고주파 변압기의 동손과 고주파 변압기의 누설에너지와 순환전류의 증가로 인한 1차단의 브릿지의 주 스위칭 소자의 도전손실의 문제점들을 가지고 있다. 이러한 도전손실의 문제점을 보완하기 위하여 본 논문에서는 FB DC-DC 컨버터의 새로운 토폴로지를 제안하고 시뮬레이션하였다. This paper proposed that reducing conduction losses on power supply for welding machine. Recently, all the Soft-Switching method has both merits and demerits. to aadapted industrial machines' power supply. The conventional Phase-Shifted FB DC-DC converter that used power supply for welding machine primarily, have problems that the copper loss in the high frequency transformer and conduction losses of bridge main switching device in the 1st terms, because of the leakage energy in the high frequency transformer and inducing of circulating current. To improved this demarit, this paper suggested and simulated a new topology of Phase-Shifted FB PWM DC-DC converter. - To minimized a circulating current.

운동영역의 상관성을 선택적으로 이용한 고속 움직임 추정 기법

임경원,송병철,나종범 한국방송공학회 1996 한국방송공학회 학술대회 Vol.1 No.1

This paper describes a new hierarchical block matching algorithm especially appropriate for a large search area. The proposed algorithm consists of higher level search for an initial motion vector estimate by using a new matching criterion over the evenly subsampled search points, and lower level search for the final motion vector refinement. In the higher level matching criterion, mean absolute differences at the search points (or motion vector candidates) similar to motion vectors of causally neighboring blocks, are weighted properly so that these points can have a higher chance to being selected. The proposed algorithm outperforms existing hierarchical block matching algorithms, and its computational regularity makes hardware implementation simple.

External Validation of 3 Risk Scores in Adults with Congenital Heart Disease

Bunty K. Ramchandani,Luz Polo,Raúl Sánchez,Juvenal Rey,Álvaro González,Jesús Díez,Ángel Aroca 대한심장학회 2019 Korean Circulation Journal Vol.49 No.9

Background and Objectives: Adults with congenital heart disease (CHD) are an increasing group of patients thanks to the survival of over 85% of children with CHD. 20% of these patients shall warrant a surgical procedure during their life span. However, currently there is no one risk score that assess correctly the mortality of these procedures. Thus, we analyse the risk scores used at our institution. Methods: From May 1991 till June 2017, 608 procedures in adults with CHD were performed. The 3 risk scores (risk adjustment for congenital heart surgery [RACHS-1], Aristotle, and Euroscore I) of each procedure were analysed. We used area under the receiver operating characteristic curve (c-index) to measure model discrimination, and Hosmer-Lemeshow (H-L) statistic along with calibration plots to measure calibration. Results: There was no statistical difference between the area under the curve for the 3 scores (χ2=0.58 with 2 df, p=0.750). There was no evidence of lack of fit for RACHS-1 (H-L, χ2=2.61; p=0.271) and Aristotle score (H-L, χ2=5.69; p=0.459). However, there was evidence in lack of calibration in the Euroscore I scoring system (H-L, χ2=33.69; p<0.001). The calibration slope for RACHS-1 was 0.912, for Aristotle (stratified in risk groups) was −0.14 and for Euroscore 1 (stratified in risk groups) was 0.46. Conclusions: RACHS-1 seems to be best risk scoring system for calculating mortality applied to surgery in adults with CHD.

Infected False Aneurysm of Brachiocephalic Trunk - Rare but Highly Lethal Cause of Dyspnea

Marek Hudák,Martin Koščo,Mária Rašiová 대한혈관외과학회 2023 Vascular Specialist International Vol.39 No.2

False aneurysm of the brachiocephalic trunk is a very rare but highly lethal, lifethreatening, and difficult-to-treat condition. In this report, we present a case of a patient who suffered from rapidly worsening dyspnea caused by infected false aneurysm of the brachiocephalic trunk compressing the trachea that was successfully treated by stent graft implantation. The main purpose of this article is to consider other, less common causes of dyspnea and to explain the pathogenesis of infected true/false aneurysm and its management. Due to the rarity, history-taking and physical examination should be thorough, and symptoms and signs should be analyzed deeply. Simplification should be avoided during diagnosis. In addition, we would like to highlight the option of stent grafts as an alternative to surgery in the management of patients suffering from infected aneurysm who are at high surgical risk.

맥주박 발효사료 및 대두의 급여가 한우 거세우의 육성성적 및 도체등급에 미치는 영향

박병기,길준민,김종복,홍병주,라창식,신종서 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.3

본 연구는 한우 거세 비육우에 맥주박을 이용하여 개발한 발효사료 및 분쇄대두의 급여가육성성적, 혈액성상 및 도체등급에 미치는 효과를 검토하고자 실시하였다. 공시축은 한우사육농가에서 평균 체중 455±25.9㎏의 한우것 비육우 20두를 공시하여 실시하였다. 시험구 처리는 모든 처리구에 배합사료와 볏짚을 기본사료로 급여하였으며, 배합사료를 전량 급여하는 대조구(Control), T1(배합사료:맥주박 발효사료=60:40), T2(배합사료:분쇄대두=80:20), T3(배합사료:맥주박 발효사료:분쇄대두=50:40:10) 및 T4(배합사료:맥주박 발효사료:분쇄대두=40:40:20)로 구분하였으며, 본 연구의 결과를 요약하면 다음과 같다. 일당증체량은 비록 통계적인 유의성은 인정되지 않았지만 대조구에 비해 처리구들에서 다소 증가하는 경향을 보였다. 사료효율의 경우 대조구, T1, T2, T3 및 T4에서 각각 11.90, 8.25, 9.44, 6.69 및 7.71로 나타나 T2를 제외한 처리구들에서 대조구에 비해 사료효율이 유의적으로 개선되는 결과를 보였다(P<0.05). 혈중 BUN 농도는 대조구에 비해 T4에서 유의적으로 높은 것으로 나타났으나(P<0.05), 반면에 혈중 creatinine 농도의 경우에는 대조구에 비해 T4에서 유의적으로 낮은 결과를 보였다(P<0.05). 대조구, T1, T2, T3 및 T4의 혈중 glucose 농도는 각각 51.00, 59.39, 62.44, 62.17 및 54.00mg/㎗로 나타나 대조구에 비해 처리구들에서 대체적으로 높은 결과를 보였다. 등지방두께의 경우 T3에서 대조구 및 다른 처리구들에 비해 다소 두꺼워지는 것으로 나타났다. 배최장근단면적의 경우 T1, T3 및 T4에서 대조구에 비해 개선되는 것으로 나타났다. 대조구, T1, T2 및 T4의 A등급 출현율은 각각 66, 33, 75 및 33%로 나타났다. 결과적으로 맥주박 발효사료를 단독 급여하게 되면 사료단가는 낮추면서도 비육우의 증체율 및 도체등급에는 영향을 미치지 않게 되는 장점이 있을 뿐만 아니라 분쇄대두와 맥주박 발효사료를 혼합 급여하게 되면 증체율 및 사료효율을 증가시킬 수 있는 효과가 있기 때문에 맥주박 발효사료와 적정 비율의 분쇄대두(농후사료 급여량의 10%)는 것우를 위한 비육사료로서 효과적으로 이용될 수 있는 것으로 판단된다. 또한 맥주박 발효사료 제조과정에서 사료에 대한 발효처리는 맥주박 발효사료의 저장성을 크게 높여주기 때문에 맥주박과 같이 고수분부산물을 가축의 사료자원으로 활용하는 데 있어서 의미하는 바가 큰 것으로 판단된다. This study was conducted to examine the feeding effects of FFWBG (fermented feedstuff with wet brewer's grain) and GS(grinding soybean) in Hanwoo steers. For this research, total twenty steers(average body weight : 455.7±25.9㎏) were grouped into control(formula feed), T1(formula feed:FFWBG=60:40), T2(formula feed : GS=80:20), T3(formula feed :FFWBG=50:40:10), and T4(formula feed : FFWBG : GS=40:40:20), each treatment was allocated to four steers. There was a tendency to be increased average daily gain in T1, T2, T3 and T4 compared with the control even though no statistical significance was found. The feed conversion of T1, T2, T3 and T4 were beneficially better than that of control(P<0.05; 5.25, 9.44, 6.69 and 7.71 vs 11.90, respectively). The blood urea nitrogen concentration of T4 was higher than that of control(P<0.05), but the creatinine concentration of T4 was lower than that of control(P<0.05). The glucose concentration of T1, T2, T3 and T4 were higher than that of control(P<0.05; 59.39, 62.44, 62.17 and 54.00 vs 51.00㎎/㎗, respectively). The back-fat thickness of T3 was thicker than that of control, T2, T2 and T4. The rib-eye area of T1, T3 and T4 was wider than that of control. Appearances percentage of 'A' ranked meat quantity were 66, 33, 75 and 33% in control, T1, T2 and T4, respectively.

Myopericarditis caused by severe acute respiratory syndrome coronavirus 2

İbrahim Ulaş Özturan,Beril Köse,Buğra Özkan,Ataman Köse 대한응급의학회 2020 Clinical and Experimental Emergency Medicine Vol.7 No.4

A 25-year-old man presented to the emergency department with acute-onset chest pain and shortness of breath. A physical examination revealed coarse crackles in the both lower lungs. Consolidation and ground-glass opacities suggesting viral infection were detected in the right lower lobe on chest computed tomography. Laboratory findings revealed elevated troponin, leukocytosis, and lymphopenia. Electrocardiography revealed ST segment elevation with PR depression in leads I, aVL, V5, and V6, and ST depression and PR elevation in aVR. Echocardiography revealed diffuse cardiac hypokinesia and a decreased left ventricular ejection fraction. Suspecting coronavirus disease 2019 (COVID-19)–related myopericarditis, the patient was hospitalized. After one week of empirical antibiotics, antivirals, and supportive therapy, his condition improved. Antibody testing for COVID-19 was positive on hospitalization day 8. The presentation of myopericarditis can be vague and mislead physicians during the COVID-19 pandemic. Myopericarditis should be included as a differential diagnosis for patients with suspected COVID-19.

Experimental Investigation of Impact Behaviour of RC Slab with Different Reinforcement Ratios

Tolga Yılmaz,Nevzat Kıraç,Özgür ANIL,R. Tuğrul Erdem,Gökhan Kaçaran 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.1

Reinforced concrete (RC) slabs may be exposed to the low-velocity impact load during their service periods. In low-velocity impact scenarios, the effect of strain rates has been remarkably higher than quasi-static loading because the loading duration is very short. Thus, structural responses and failure modes will be different. The present study aims to investigate dynamic response and failure modes of simply supported two-way RC slabs exposed to low-velocity impact load. In the experimental part of this study, nine RC slabs with the dimension of 1,000 × 1,000 × 80 mm were tested. The reinforcement ratio of RC slabs and the input impact energy applied to RC slabs were experimental variables investigated. A drop-weight test setup was utilized to apply impact load to RC slabs. By varying drop-height as 1,000, 1,250 and 1,500 mm, three different impact energies have been applied to RC slabs via a hammer of which weight is 84 kg. The time histories of the accelerations, displacements and impact loads were recorded. The dynamic responses obtained by tests and the failure modes observed has been interpreted in detail. Besides, a finite element model where explicit dynamic analysis is performed has been established for verification of the experimental results. There was observed good accordance between numerical and experimental results. Consequently, it is considered that the present finite element treatment can be used for the evaluation of the dynamic responses and failure modes of RC slabs exposed to low-velocity impact load.