Neural Spike Train Decoding에 기반한 인공와우 어음처리방식 성능평가

김두희,김진호,김경환,Kim, Doo-Hee,Kim, Jin-Ho,Kim, Kyung-Hwan 대한의용생체공학회 2007 의공학회지 Vol.28 No.2

We suggest a novel method for the evaluation of cochlear implant (CI) speech processing strategy based on neural spike train decoding. From formant trajectories of input speech and auditory nerve responses responding to the electrical pulse trains generated from a specific CI speech processing strategy, optimal linear decoding filter was obtained, and used to estimate formant trajectory of incoming speech. Performance of a specific strategy is evaluated by comparing true and estimated formant trajectories. We compared a newly-developed strategy rooted from a closer mimicking of auditory periphery using nonlinear time-varying filter, with a conventional linear-filter-based strategy. It was shown that the formant trajectories could be estimated more exactly in the case of the nonlinear time-varying strategy. The superiority was more prominent when background noise level is high, and the spectral characteristic of the background noise was close to that of speech signals. This confirms the superiority observed from other evaluation methods, such as acoustic simulation and spectral analysis.

Spike Train Decoding에 기반한 인공와우 어음처리기의 음성시작점 정보 전달특성 평가

김두희,김진호,김경환,Kim, Doo-Hee,Kim, Jin-Ho,Kim, Kyung-Hwan 대한의용생체공학회 2007 의공학회지 Vol.28 No.5

The adaptation effect originating from the chemical synapse between auditory nerve and inner hair cell gives advantage in accurate representation of temporal cues of incoming speech such as speech onset. Thus it is expected that the modification of conventional speech processing strategies of cochlear implant(CI) by incorporating the adaptation effect will result in considerable improvement of speech perception performance such as consonant perception score. Our purpose in this paper was to evaluate our new CI speech processing strategy incorporating the adaptation effect by the observation of auditory nerve responses. By classifying the presence or absence of speech from the auditory nerve responses, i. e. spike trains, we could quantitatively compare speech onset detection performances of conventional and improved strategies. We could verify the effectiveness of the adaptation effect in improving the speech onset representation characteristics.

낙동강 본류에 서식하는 붕어에서의 납, 카드뮴과 아연의 함량

김두희,김용구,장봉기,Kim, Doo-Hie,Kim, Yong-Gu,Jang, Bong-Ki 대한예방의학회 1988 Journal of Preventive Medicine and Public Health Vol.21 No.2

낙동강 중류의 수질과 그 수계에 서식하는 어류와 납, 카드뮴 및 아연과의 관계를 붕어를 대상으로 관찰하였다. 본 실험을 위한 표본은 비교적 갈수기라고 인정되는 3월 초순에 안동댐, 낙동교, 왜관, 강정, 개포 인근 그리고 낙동강의 주 오염원이 되는 금호강에서는 팔달교 부근에서 채취하였으며 수중 중금속 및 조직 중 납, 카드뮴과 아연은 원자흡광분광광도계(IL-551)로 분석하였다. 낙동강의 상류에서 하류로 내려올수록 납, 카드뮴, 아연 함량은 증가하였고, 팔달교 부근은 강정 상류보다 $3{\sim}5$배 더 높았으며 이는 낙동강과의 하류지점에서 약 40km 하류에 위치한 개포의 수질보다 약 1.5배 정도 높게 나타났다. 붕어의 뼈, 근육, 지느러미 중의 납, 카드뮴 함량도 상류에서 포획한 것보다 하류에서 포획한 것이 많았다. 강정을 포함한 상류보다 오염수역이라고 할 수 있는 개포 및 팔달교 근처의 붕어에서 유의성 있게 높았다. 붕어의 뼈조직 중 납, 카드뮴, 아연의 함량은 조사 전역에 걸친 그들 수환경보다 각각 $771{\sim}2,856$배, $188{\sim}564$배, $663{\sim}1,327$배이었으며 근육에서는 각각 $170{\sim}516$배, $62{\sim}169$배, $247{\sim}389$배이고 지느러미에서는 각각 $484{\sim}1,770$배, $122{\sim}360$배, $509{\sim}983$배 이었다. 이들 붕어의 성장 햇수별 납, 카드뮴 및 아연 함량은 연령이 증가할수록 증가했으며 각 수역에서의 동일 연령군까지 비교했을때는 상류에서 하류로 내려갈수록 그 함량이 많았다. 팔달교에서의 $0{\sim}1$세군에서의 뼈 중 납의 함량은 개포의 $4{\sim}5$세군과 근사하며 강정 상류의 $3{\sim}4$세군보다 높은 경향을 보였다. 이상과 같은 결과를 요약하면 낙동강은 금호강의 탁류의 영향을 크게 받아 오염 수역에서 포획한 어군은 비오염수역의 어군보다 중금속 함량이 유의하게 높으며 성장 햇수가 많아짐에 따라 중금속 함량은 높다는 것을 알 수있다. In order to determine the contents of lead, cadmium and zinc, the tissues of the crussian carp, Carassius carassius, collected from the middle streams of the Nakdong river were examined. During the dry season from 8 to 15, March, 1987, six loci were selected to sample the fish and river water; five of them were the midstreams of the Nakdong river i. e., the vicinities of the Andong dam, the Nakdong bridge, the Waegwan bridge, Gangjung and Gaepori, the other one was the Kumho river around the Paldal bridge(see Fig. 1). The microanalyses of lead and cadmium contents were undertaken by the atomic absorption spectrophotometer(Model IL-551) connected with CTF-IL 655, while that of Zinc by the flame method with IL551 only. The contents of lead and cadmium in water sampled from Gaepori distant from about 30km downward from the junction with the Kumho river were about 1.5 times higher than those from Gangjung distant about 0.5km upward from the junction, and the content of zinc from Gaepori was slightly higher than that from Gangjung. However, the contents of lead and cadmium in water sampled from Gaepori were three fifth of those from the vicinity of Paldal bridge far about 2km upperward from the junction. In the other words, the contents of lead and cadmium in the samples from the vicinity of the Paldal bridge were about 2.5 to 3 times higher than those from the Gangjung and 5 times higher than those from the Andong dam. The contents of the heavy metals in the tissues of Carassius carassius were relatively consistent to those of the aquatic environments where the fish were collected, with higher contents in the tissues of the crussian carp collected from the vicinity of Gaepori and the Paldal bridge which were so much polluted than in those from other loci in upper stream from the junction. And the contents of lead and cadmium in tissues were positively correlated with the age of the fish, however, that of zinc was not. The contents of lead in bone of crussian carp from the vicinity of the Paldal bridge in the group of 0-1 year old fish were similar to those of 4-5 years old fish from Gaepori, and higher than those of 3-4 years old fish collected from the upper stream of the junction. It is likely that fishing from Gaepori and the paldal bridge is not recommended, and all the industrial producers have to pay intensive attention to the water pollution due to the sewage disposal.

대구지방 산업장에 있어서 건강장애요인과 작업환경검사에 대한 기업인의 수용태도 (ll)

김두희,성수원,Kim, Du-Hui,Seong, Su-Won 대한산업보건협회 1988 산업보건 Vol.8 No.-

Examination of working environments was conducted to get more detailed data about harmful working environments and to make a contribution to more effective management. Study was carried out on 722 factories located in Taegu city and eight counties in Kyungpook Province, Korea, for a period of one year, from February 1 to December 30, 1986. The total number and proportion of workers exposed to harmful material was 37,697, 45.2% among 83,368 workers. The results according to exposed material were as follows: 1. In the case of noise, proportion of exceeding the 8-hour TLV was 59%, Included were nail-cutting in assembly metal manufacturing industry and weaving process in textile. 2. Dust in mill process of coal manufacturing industries exceeded the TLV of second class of dust at all parts and exceeded the TLV at 6% as a whole.: 3. The fields of industry lower than 70 lux of illumination were storage equipment of food, auto-winder of textile, painting of wood wares and coal mixing, and 44% of all cases was lower than standard. 4. As a result of temperature index investigation(WBGT), about 12% of all sujects exceeded limit value. Included parts were rolling machine and reducing room. 5. In the case of organic solvents, TLV was exceeded at about 8%, The parts exceeded TLV according to materials belonged to this category were as follows. 1) Toluene: adhesive work in assembly metal manufacturing 2) Xylene: printing and paint mixing in chemical manufacturing 3) Methyl ethytl ketone: paint mixing in all parts examined and coating machine partially in chemical manufacturing 4) Methyl isobutyl ketone: printing in chemical manufacturing 5) Acetone: vapor polishing in assembly metal manufacturing 6. Among specified chemical materials, the concentration of HC1 in the air in metal assembly manufacturing factory exceeded TLV. in one of three assembly metal manufacturing examined. Others, such as benzene, acetic acid, formic acid, sodium hydroxide, formalin, ammonia, copper, chromate etc. were lower than TLV in its indoor atmospheric concentration. As a whole, the proportion of exceeding TLV was about 0.8% 7. The concentrations of inorganic lead were lower than TLV in all parts examined. The results of this investigation show the fact that current management of working environments is not satisfactory, and so more active management is needed.

대기중(大氣中) 배출(排出)된 일산화탄소(一酸化炭素)와 아황산(亞黃酸)가스의 지속시간(持續時間)

김두희,Kim, Doo-Hie 대한예방의학회 1974 예방의학회지 Vol.7 No.2

일산화(一酸化) 탄소(炭素)에 대한 피해와 대기오염(大氣汚染) 기준을 아황산(亞黃酸)까스를 기준으로 한다는 데의 관심을 가지고 가정에서 많이 사용하고 인는 연탄을 중심으로 관찰한 결과 CO는 연소온도와 비례하나 $SO_2$는 비례하지 않으며 일단 발생된 CO는 적어도 24시간(時間) 이내에는 변화가 거의 없으며 비교적 장시간 유지한다. $SO_2$는 대기중에서 곧 변화를 일으켜 ($H_{2}SO_{4}$로 전환) 30분이내에 극소량으로 되므로 대기중의 황화물 측정은 $SO_2$보다 유황자체나 $H_{2}SO_{4}$를 측정함이 더욱 효과적이라 하겠다. The concentration of Carton momoxide(CO) and Sulful dioxide($SO_2$) by burning time of coal, and its time of fading out in atmosphere after effluence from stove were measured with Kitagawa gas detector, January, 1974. Gas for measurement was sampled by gas syringe at the point distanced 60cm. from first junction of garvanized pipe of stove. CO concentration was directly proportional to the burning temperature of coal but $SO_2$ was generally constant durning burning time or also in proportion to burning temperature. CO gas of effluent mixed with air(relative humidity, 40%) was maintained for long period relatively, but $SO_2$ gas was early faded out within short time. The period decreasing to allowable limit was about 4 days in former and about 30 minutes in later, respectiively.

도금공(鍍金工)에 대한 임상적(臨床的) 관찰(觀察)

김두희,Kim, Doo-Hie 대한예방의학회 1977 예방의학회지 Vol.10 No.1

${\ulcorner}$크롬${\lrcorner}$과 ${\ulcorner}$니켈${\lrcorner}$등의 도금(鍍金)을 하는 도금공(鍍金工)에 대하여 그 직업성질환(職業性疾患)을 관찰(觀察)하고 저 1976년(年) 6(월)月 대구시내(大邱市內) 소재(所在)하는 서로 유사한 종류와 방법으로 작업하고 있는 중소기업체(中小企業體) 중 작업환경개선(作業環境改善)이 어느 정도 되어 있는 곳과 전연 되어있지 않는 곳을 각각 1개소(個所)씩 선택(選擇)하며 비교해 본 결과 다음과 같이 요약(要約)할 수 있었다. 전반적(全般的)으로 비강내(鼻腔內) 증상(症狀)이 총출현빈도(總出現頻度) 중 50%이상을 점하며 다음 현기증(眩氣症)이 문제(文題)로 되어 있으며 환경개선(環境改善)을 함에 따라 비강내증세(鼻腔內症勢)중에서 괴양성 병변(病變)을 줄이어 증상(症狀)은 가볍게 되었으나 개입보호구사용(個入保護具使用)을 소홀히 함으로써 점차 만성적인 변화(變化)를 초래할 염려가 있었다. 각종 혈액상(血液相)중 ${\ulcorner}$헤모글로번${\lrcorner}$, ${\ulcorner}$헤마토크리트${\lrcorner}$ 적혈구(赤血球)와 요소견(尿所見)중 단백질당(蛋白質糖), ${\ulcorner}$우로비리노겐${\lrcorner}$등에는 큰 영향을 미치지 않고 있다고 생각된다. This is a result of clinical examination for workers working with Chromic acid and Chromium compounds in the plating room of their companies. I selected two companies that the plating process and the kinds of plating were similar. One (SW Co.) was more or less improved the operating environment with the ventilation machine so on and another (SR Co.) did not it so. The former was examined at March 29th 1977, the latter was at June 28th 1976. But the respiratory communicable diseases, flue or common cold so on were not spreaded there at that time. The clinical aspects were compared between the group of SW, and SR. The swelling and hyperemic signs of nasal mucous membrane and the experience of nasal bleeding were about 50%, generally, in all the groups. The following problem was dizziness or vertigo. The nasal signs in the group of SW (improved ventilation of the room air) were relatively weak, but in another, it was some what severe; - there was necrotic sign with thick nasal clast. They were only used of gauze mask when the vapors of various solvents were deeply full in the room. And there was very high rate of bronchial signs, sputum or coughing in the group of SW improved ventilation so called, than another one. I suppose that it means chronic inflammatory change of the bronchial mucous membrane with deeper signs, due to the individual protectors were carelessly or not used according to the improving of the operating environment. Theses nasal signs mentioned the above were not nearly in the other groups had not been done the Chromium plating. The Status of RBC, Hb and Ht, of urine protein and urobilinogen were mostly in normal range. But the number of WBC was more or less showed with a positive correlation to the working duration.

정신지체아 두발 중 중금속 함량 IV - 구리와의 관련성 -

김두희,남상숭,박순우,Kim, Doo-Hie,Nam, Sang-Soong,Park, Soon-Woo 대한예방의학회 1989 Journal of Preventive Medicine and Public Health Vol.22 No.4

The relationship between copper content in scalp hair and mental retardation was investigated. Samples of scalp hair were collected from 297 mentally retarded children who were students in one of two schools providing special educational services, one, consisted of children living in an orphan home, the other, children living with parents. For comparison, 117 scalp hair samples were collected from the children who had got average or above average academic achivement in a regular elementary school. Hair samples were taken from the nape of the neck and the copper content was determined by an atomic absorption spectrophotometer (IL 551). There was no statistically significant difference in scalp copper levels across different age groups except female orphan group, but no trend or correlation between copper conents and age was found. The hair copper contents of the mentally retarded children groups were significantly lower than that of control groups. But there was no dose-response relationship between degree of mental retardation and hair copper level. The hair copper contents of the group accompanied by Down's syndrome and unknown group were significantly lower than that of control group in both sex, and in the case of accompanied by epilepsy or autism, lower than control group in male. Although the results of this study show no evidence that mental retardation has owed to copper deficiency, the possibility of copper deficiciency in their fetal or infant age could not be ruled out. Thus further study is needed to determine whether mental retardation could be attributed to copper deficiency, through the examinations about their living environments, dietary pattern, eating habit and the impact of copper deficiency on brain development.

잠사회사(蠶絲會社) 여공(女工)의 피부질환(皮膚疾患)

김두희,Kim, Doo-Hie 대한예방의학회 1976 예방의학회지 Vol.9 No.1

잠사회사(蠶絲會社) 근로자(勤勞者)의 직업성질환(職業性疾患)을 분석해 보기 위하여 1975년(年) 11월(月) 근로조건(勤勞條件)이 같은 대구시내(大邱市內) 모잠사회사(某蠶絲會社) 여자근로자(女子勤勞者) 177명(名)에 대하여 집단건강진단시(集團健康診斷時) 시진(視診)에 의하여 실시(實施)한 결과 다음과 같이 요약할 수 있었다. 전(全) 여자근로자(女子勤勞者)에 있여서 각종피부질환(各種皮膚疾患)의 유병률(有病率)이 53%로 반수(半數)이상에 달하여 피부질환(皮膚疾患)은 대체(大體)로 3가지로 대분(大分), 손톱마모(磨耗), 피부(皮膚)의 각화, 나류(裸瘤), 구열(龜裂) 등과 같은 피부변화(皮膚變化)(47.5%)가 가장 많으며 알레르기 반응(反應)(14.7%)과 기타 무좀 등의 순이었다. 피부변화(皮膚變化)는 그 진행정도(進行程度)의 차이(差異)가 있었으나 대개 복합적(複合的)으로 발생(發生)하여 근속년수와는 무관한 것 같으나 대체적으로 2년이상 근속자에게 빈발하는 경향을 보이며 손톱마모(磨耗)는 이에 따라 현저(顯著)한 차이(差異)를 보이고 있다. 알래르기 반응(反應)은 입사후(入社後) 수개월 이내에 발생(發生)하며 다시 접촉 여하에 따라 그 정도로 달라지게 되는 것 같다. 계속 근무자보다 과거에 경험한 바 있는 자에서 다소 그 빈도가 높은 경향을 보여 준다. 호발부위(好發部位)는 역시 접촉이 잦은 손가락부터 손바닥, 손, 팔, 다리, 얼굴, 목, 몸통등 광범하게 번져가며 심한 경우 습진 양으로 변해 가고 있다. The occupational skin diseases in an industry of silk reeling located in Daegu city of Korea were analyzed by inspection through a mass survey for improving the workers' health, November, 1975. The subjects, 177 persons were all females, and were distributed at 18-38 years old. About two thirds were under 25 years old. The meanage was 23.6 years. The incidence of skin diseases was about 53%. It was generally divided into three groups;- the epidermic changes of those were most frequent, 47.5%, the allergic reactions were 14.7%, and athlete's foot was only four cases, 2.3%. Most frequent signs of epidermic changes was the worn-out nail, 32.3%; and the keratolysis, 28.8%; and the callus, 15.3% were followed in order. Theses were significant in five per cent level between the sections of the silk reeling and the manufacturing;-Allergic reactions and worn-out nail were more frequent in the manufacturing group than the silk reeling, and keratolysis and callus were inverted proportionally. Allergic reactions were occurred within a few months from first entrance time, and it was more frequent in the group exposed to same allergen in the past than the continuing group from first. Most of the appearing sites of theses were hands, and infrequently, it was occurred in the face, neck, trunk, knee anfeet. These epidermic changes except allergic phenomena were appeared in the fingers, palmal and dorsal surface of hands frequently contacted. But these changes and allergic reactions were generally combined with two or more kinds.

내가 본 한국의 산업보건

김두희,Kim, Du-Hui 대한산업보건협회 2000 산업보건 Vol.148 No.-

정신분열증 환자의 두발 중 구리 및 수은 함량과 그 인성과의 관련성

김두희,강영우,박순우,이근후,이영숙,Kim, Doo-Hie,Kang, Young-Woo,Park, Soon-Woo,Lee, Kuen-Hoo,Lee, Young-Sook 대한예방의학회 1990 예방의학회지 Vol.23 No.3

정신분열증과 수은 및 구리와의 관계를 보기 위해 정신병원에 입원중인 만성 정신분열증 환자중 만 20세에서 29세까지의 남자 80명과 대조군 69명을 대상으로 두발 중 구리와 수은 함량을 원자흡광광도계로써 측정하고 아울러 이들에게서 다면적 인성검사(MMPI)를 실시하였다. MMPI의 각 척도별 T-점수를 환자군과 대조군으로 나누어 비교한 결과 Hs, D, Pd, Pa, Pt, Sc척도에서 환자군이 대조군에 비해 유의하게 높은 점수가 나왔고 점수 구간에 따른 분포도 환자군과 대조군 사이에 유의한 차이가 있었다. 구리의 경우 환자군의 두발 중 함량이 $11.17{\pm}3.72ppm$으로 대조군의 $18.93{\pm}7.81ppm$에 비해 유의하게 낮았으며 수은의 경우는 환자군이 $2.42{\pm}1.46ppm$으로서 대조군의 $1.68{\pm}1.07ppm$에 비해 유의하게 높았다. 이때 거주지에 따른 차이는 볼 수 없었다. 구리와 수은은 역상관관계(r=-0.25)를 보였으며 통계학적으로 유의하였다. MMPI의 T점수에 따른 구리 함량은 10개 척도 모두에게 유의한 차이가 없었다. 수은의 경우는 Pt척도와 Sc척도에서 각 점수군간에 통계학적으로 유의한 차이가 있었다. T점수의 70점 이상과 미만의 두 군간을 비교하였을 때는 70점 이상군의 Pa척도, Pt척도, Sc척도에서의 수은 함량이 각각 $2.72{\pm}1.49ppm,\;2.93{\pm}1.27ppm,\;2.66{\pm}1.42ppm$으로서 70점 미만군의 $1.97{\pm}1.30 ppm,\;1.98{\pm}1.32 ppm,\;1.92{\pm}1.29ppm$에 비해 유의하게 높았다. 다른 척도의 경우에도 통계학적인 의의는 없었지만 Mf척도를 제외하고는 전반적으로 70점 이상군이 미만군보다 수은 함량이 더 높았다. 그리고 D, Pa, Sc척도에서는 T점수가 증가함에 따라 수은 함량도 유의하게 증가하는 양상을 보였다. 환자군과 대조군으로 나누었을 때 구리의 경우 대부분 척도의 각 점수군에서 환자군이 대조군에 비해 유의하게 함량이 낮았으며 수은의 경우는 D척도의 44점 이하군, Hy척도의 $45{\sim}59$점군, Pd척도의 $60{\sim}69$점군, Mf척도의 $45{\sim}59$점군, Ma척도의 $60{\sim}69$점군, Si척도의 44점 이하군에서만 환자군이 대조군에 비해 유의하게 높은 수치를 나타냈다. 본 연구의 결과로 볼 때 구리의 결핍이나 수은의 과다 섭취가 정신분열증의 발병 혹은 증상 악화에 영향을 끼칠 수 있을 가능성을 짐작해 볼 수 있으며 이들 금속과 정신분열증의 상관관계, 그리고 인성과의 관계에 대해 계속 연구해 볼 필요성을 느낀다. The relationship between copper and mercury contents in the scalp hair and chronic schizophrenia was investigated. The samples of scalp hair were collected from 80 male chronic schizophrenic patients at the age from 20 to 29, who were hospitalized in the National Psychiatric Hospital in Seoul. As the control group, 69 males were collected from general population. Hair samples were taken from the napes and the Minnesota Multiple Personality Inventory (MMPI) was performed also. The copper and mercury contents were determined by an atomic absorption spectrophotometer. Significantly higher T-score of MMPI was seen in patients group for Hypochondriasis Scale (Hs), Depression Scale (D), Psychopathic Deviate Scale (Pd), Paranoia Scale (Pa), Psychasthenia Scale (Pt), Schizophrenia Scale (Sc) subscales than control group, and the frequency distribution by T-score was also significantly different between the patient and the control group for above scales. The content of copper in the hair of patient group was significantly lower than the control group. In the case of mercury, the mean value of patient group was significantly higher than control group. Between the value of copper and mercury, statistically significant negative correlation (r=-0.25) was found. When grouped by the T-score of MMPI, there was no difference of copper contents between T-score subgroup at all MMPI scale. But the mercury contents showed significant difference between T-score subgroup at Pt, Sc scale. When compared between the group of above 70 T-score and the group of less than 70, the mercury contents of Pa, Pt, Sc scale of above 70 T-score group were significantly higher than the group of less than 70. In other scales, the mercury content of the above 70 group were higher than the group of less than 70 except Mf scale, although there were no statistscally significances. In D, Pa, Sc scales, as the T-score of MMPI increased, the contents of mercury also increased. When divided into the patient group and the control group, the copper contents of the patient groups were significantly lower than the control group at each T-score scale in most MMPI scales. In the case of mercury, the value of patient group were significantly higher than the control group in the less than 44 scale of D, in the $60{\sim}69$ scale of Pd, in the $45{\sim}59$ scale of Mf, in the $60{\sim}69$ scale of Ma, in the less than 44 of Si. These results suggest that the effects of the deficiency of copper or high intake of mecury on schizophrenia and personality may be of possible value. Thus further studies are necessary to determine whether schizophrenia and personality formation would be attributed to copper deficiency or mercury intake.