Strong dependence of photocurrent on illumination-light colors for ZnO/graphene Schottky diode

이화욱,안남현,정석진,강순홍,권순기,이지수,이영민,김득영,이세준 한국물리학회 2017 Current Applied Physics Vol.17 No.4

The ZnO/graphene Schottky diode reveals a strong dependence of its photocurrent on the color of the illuminating lights (i.e., a dependence of photocurrent on the photon energy). As the photon energy increases, the magnitude of photocurrent is exponentially increased. Particularly, in comparison with the red-light illumination, the device clearly exhibits approximately 100-times-increased photocurrent when illuminating the ultra-violet light. We attribute this feature to the increase in photo-excited carriers at the depletion region in ZnO. The results suggest that the ZnO/graphene Schottky diode holds promise for the application in high-performance color-selectable photodetectors.

소아에서의 경부심부감염에 대한 임상적 고찰

양윤수,이화욱,이상헌,홍기환 대한이비인후과학회 2004 대한이비인후과학회지 두경부외과학 Vol.47 No.12

Backgroud and Objectives:The objective of this study was to clarify the presenting signs and symptoms, clinical course, path-ologic organisms, and management of deep neck infections in children. Subjects and Method:We retrospectively reviewed the in-patient charts of children treated at our ENT department for dep neck infections. Thirty-six such patients were identified Results:During the 4-year period, 36 children with deep neck space infection were diagnosed and treated, including 20 (56% ) boys and 16 (44% ) girls. The ages ranged from 11 months to 15 years, with the mean of 6.9± 4.5 years. The most common site of infection was the peritonsillar space (41.7%), folowed by the parapharyngeal (27.8%) and submandibular (16.6%) space. Six (16.6%)space. The most comonly known associated preceding ilness was viral upper respiratory infection (53% ). Neck sweling, fever, and dysphagia were the most frequent symptoms. The most common pathogens were Streptococcus pyogens (3/10) and Sta-phylococcus aureus (2/10). The mean duration of hospitalization was 7.7 days (range, 2- 15). Leukocytosis (WBC>15000/m3) was found in 13 (36% ) patients. All patients received parenteral antibiotics after admision. Thirteen (36% ) children recovered from the infection with conservative treatment and twenty-three (64% ) children received surgical drainage. No complication and tracheotomy occured. Conclusion:Dep neck space infections in children are rapidly progressive and usually present with neck swelling and fever. Peritonsillar space and Streptococus pyogens infections were most common anatomic sites and pathogen

경부에 발생한 괴사성 근막염에 대한 임상적 고찰

양윤수,이화욱,김진성,이재근,홍기환 대한이비인후과학회 2005 대한이비인후과학회지 두경부외과학 Vol.48 No.8

Background and Objectives:To clarify the presenting signs and symptoms, clinical course, pathologic organisms, and management of cervical necrotizing fasciitis. Subjects and Method:We retrospectively reviewed the inpatient charts treated at our ENT department for cervical necrotizing fasciitis. Seven such patients were identified as having been treated from January 2002 to December 2004. Results:During the 36-months period, 7 adults consisting of 5 males and 2 females with cervical necrotizing fasciitis were diagnosed and treated. The mean age was 45 years ranging from 25 to 59 years. All patients had infections in more than five fascial spaces. The most commonly involved sites of infection were the superficial neck space (100%), followed by submandibular (85.7%), and parapharyngeal and submental space (57.1%). The most commonly known associated preceding illness were tonsillitis and dental abscess (28.5%). Painful neck swelling and difficulty in moving the neck were the most frequent symptoms and signs. The most common pathogen was Streptococcus species (4/7), followed by Staphylococcus epidermidis and Klebsiella pneumoniae (1/6). The mean duration of hospitalization was 17.2 days (range, 8-24). Leukocytosis (WBC>10000/mm3) was found in all patients. All patients received parenteral antibiotics and surgical drainage after admission. Six patients recovered and one patient died after surgical drainage. Tacheotomy was performed on five patients. Conclusion: Cervical necrotizing facilitis is an uncommon but often fatal bacterial infection of the skin, subcutaneous fat, superficial fascia, and deep fascia. It is characterized by marked tissue edema, rapid spread of inflammation, and signs of systemic toxicity. High indexof suspicion, prompt aggressive surgery, appropriate antibiotics, and supportive care are the mainstays of management.

후두질환에 따른 자음의 음성발현시간의 특성

홍기환,이화욱,김진성,이은정,소상수,최동일,양윤수,Hong, Ki-Hwan,Lee, Hwa-Uk,Kim, Jin-Sung,Lee, Eun-Jung,So, Sang-Soo,Choi, Dong-Il,Ynng, Yoon-Soo 대한후두음성언어의학회 2006 대한후두음성언어의학회지 Vol.17 No.2

Background and Objectives : Voice onset time(VOT) is defined as the time interval from oral release of a stop consonant to the onset of glottal pulsing in the following vowel. VOT is a temporal characteristics of stop consonants that reflects the complex timing of glottal articulation relative to supraglottal articulation. Stop consonants are characterized by creation of a pressure difference across a complete occlusion in the vocal tract, followed by a sudden release 'burst' due to opening that occlusion. The objects of this study is to evaluate a usefulness of voice onset time in the assessment of voice disorderd patients. Subjects : Subjects were 20 adults with normal voice and with benign laryngeal disorders. Subjects with voice disorders represented the following vocal pathologies : vocal polyp, vocal nodule, Reinke's edema and unilateral vocal fold paralysis(UVFP). Control subjects were matched for age (21-40 yews old) and sex(male) with the voice disorders subjects and had normal vocal qualities with no history of voice disorders. Methods : Each voice-disordered and matched control subject read the test passages containing three types of Korean bilabial consonants. VOT measures were made for the initial $/p/p^h/\;and\;/p'/$. VOT was measured using acoustic waveform or wide band spectrogram. Results : For each voiceless stop consonants, there was a significant difference in VOT between the voice disordered and normal subjects. The mean VOTs of the lax stops in UVFP was significantly shorter than those of control subjects in the UVFP. The mean VOTs of the aspirated stops in the vocal polyp and nodule were longer than those of control subjects, but not significant. The mean VOTs of the glottalized in voice disordered groups were longer than those of control subjects, and significant statistically in the UVFP. Conclusions : VOT may be a clinically useful acoustic parameter in the assessment of voice disordered patients, especially in the unilateral vocal fold paralysis.

組織開發을 위한 組織診斷技法

李壽陶,李和旭 경북대학교 산업기술연구소 1987 産業技術硏究誌 Vol.14 No.-

Organizations are never completely static. They are in continuous interaction with external forces. Changing consumer attitudes, new legislation, and technological breakthroughs all act on the organization to cause it to change. The degree of change may vary from one organization to another, but all face the need for adaptation to external forces. Many of these changes are forced upon the organization, whereas others are generated internally. Organization development is aimed not only at improving the Organization's effectiveness but also at enhancing the development of organization members. The field of Organization development in hierarchical systems typically involves the study of elements such as the change agent, the change process, strategies of planned change, and the introduction of planned change into an organization. The purpose of this study is to present a comprehensive theoretical framework or model for the analysis of diagnosis organization problem. Diagnosis is a systematic approach to understanding and describing the present state of the organization. The purpose of the diagnostic phase is to specify the nature of the exact problem requiring solution, to identify the underlying causal forces, and to provide a basis for selecting effective change strategies and techniques. This study has researched basic conception progress and other factors of diagnosis through the analysis of the pressure in changeable situation and resistant factors. In addition, the diagnostic process and some factors in making a diagnosis are to present sound diagnosis. Several diagnostic models have been described: (1) The Analytical Model. (2) The Emergent-Group Behavior Model. (3) The Sociotechnical Systems Model. (4) The Process Model. (5) The Force-Field Analysis Model. These models may be used by the change agent to facilitate the analysis of client system problems. And in order to support the theoretical study, the simulation of organization diagnosis is presented. The diagnosis is the method of progressing the organization development effectively, so different types of the diagnosis Models can be used according to the problem situation. And it can be expected that the organization according to the organization diagnosis will make three effects as the followings : (1) It removes the biases in solving the problems. (2) The comprehensive and thorough diagnosis makes the possibility of liquidation at the maximum. (3) The management can think the organization comprehensively and can manage it more scientifically by the comprehensive diagnosis.

미숙한 적과 사과를 이용한 사과정과의 품질특성에 관한 연구

임지현,이경림,이화욱,신승렬,오왕규,홍주연 한국식품영양학회 2019 한국식품영양학회 학술대회논문집(학술심포지움) Vol.2019 No.11

블록체인 기반의 저작권 보호를 위한 스마트 계약 기술의 활용 방안에 대한 연구

심태섭(Tae-Seob Shim),이화욱(Hwa-Wook Lee),신상호(Sang-Ho Shin) 한국통신학회 2019 한국통신학회 학술대회논문집 Vol.2019 No.6