Algal bioassay 에 의한 조류생장 제한영양염류 결정

오희목(Hee Mock Oh),이석준(Seog June Lee),김성빈(Seong Bin Kim),박미경(Mi Kyung Park),윤병대(Byung Dae Yoon),김도한(Do Han Kim) 한국하천호수학회 1998 생태와 환경 Vol.31 No.2

Determination of Limiting Nutrient for Algal Growth by Algal Bioassay. Oh, Hee-Mock, Seog June Lee, Seong-Bin Kim, Mi- Kyung Park, Byung-Dae Yoon and Do-Han Kim (Environmental Microbiology Research Unit, Korea Research Institute of Bioscience and Biotechnology, Taejon 305-333, Korea and Water Resources Research Institute, Korea Water Resources Corporation, Taejon 305-390, Korea) Water quaiity and algal growth potential (AGP) using Microcystis aeruginosa were investigated from April to September 1997 in Daechung Reservoir. Secchi disk transparency was 1.1 m in August. Chlorophyll-a concentrations were higher than 10㎍/l at all samples. Total phosphorus concentration was in a range of 0.020∼0.027mg/l which is at the approximate value of 0.03 mg/l, the general critical level of eutrophication. These results indicate that Daechung Reservoir is in an eutrophic state except some temporary times and restricted sites. Phosphorus uptake rate of M. aeruginosa was higher in the water from the epilimnion than in the hypolimnion and also higher under light condition than under dark condition. Therefore, phosphorus uptake rate appears to depend on cellular phosphorous content and light condition, a meaning of endergonic process. Phosphorus was the most frequently limiting nutrient: phosphorus was limiting algal gowth in April and May, nitrogen, phosphorus and trace elements were the limiting factors for algae in August, and trace elements in September. If a fast growing alga, M, aeruginosa, is used as a test organism for assaying AGP, in vivo fluorescence instead of dry weight can be measured for algal biomass and incubation period can be reduced from traditional 14 days to 7 days.

세율변동에 따른 법인세평준화에 관한 연구

박희석,이효섭 대구대학교 경제경영연구소 2005 경제경영연구 Vol.3 No.1

This study empirically examined mean factors to explain Tax Smoothing Trend. Samples are listed firms from 1993 through 2002 in Korea Stock Exchange, resulting in 2,209 firms(firm/year). T-test analysis is used to examine the mean difference between before and after of tax rate change. The empirical results is that Firms realized higher Tax Smoothing before tax rate change(1993, 1995, and 2001) than after tax rate change(1994, 1996, and 2002), the difference was statistically insignificant. 본 연구는 1993년부터 2002년까지 10개년 간 우리나라 상장기업 2,209개 기업/년을 대상으로 조세감면제도를 이용하여 세율 변동 전ㆍ후 법인세평준화 성향에 미치는 영향 요인을 실증 분석하였다. 법인세평준화 성향의 평균차이를 세율 변동 전과 후를 각각 1년간 t-test를 이용하여 분석하였다. 분석의 결과 세율 변동 이후 기간에서의 세율 변동 이전보다 평균적으로 법인세평준화 성향이 높을 것으로 기대하였으나, 오히려 세율 변동 이전이 상대적으로 약간 높은 법인세평준화 성향이 나타났으나 통계적 유의성은 나타나지 않았다. 본 연구는 지금까지 법인세평준화를 국내 선행연구에서 고려하지 않은 세율 변동을 연구설계에 포함시켜 연구하였다. 따라서 향후 정부의 법인세법과 조세특례제한법 등을 입법하고 조세정책 수립에 중요한 시사점을 밝히고 있다.

시판 동물성 식품의 저장온도 및 저장기간별 세균균속의 변화

박석기,이용욱,윤희정 대한보건협회 2000 대한보건연구 Vol.26 No.1

It is very important to prepare the sanitation criteria for the animal foods through the microbiological examination and the investigation of tendency to change of the organisms according to the storage temperature and period. As the results of identification of total 110 genera isolated from commercial animal foods, 15 genera were identified and predominant genera were Staphylococcus(29.1%), Pseudomonas (13.6%) and Enterococcus(12.7%) and followed by Enterobacter, Lactobacillus, Achromobacter, Aeromonas, Escherichia, Micrococcus, Bacillus, Klebsiella, Serratia and yeast. As the results of identification of 1323 isolates from commercial animal foods stored at 10℃, 20℃ and 30℃, 21 genera were identified and Staphylococcus(22.5%), Enterococcus(15.9%), Pseudomonas(15.9%), Bacillus(10.3%) were predominant. The predominant genus among 405 isolates from commercial animal foods stored at 10℃ was Pseudomonas(28.9%), followed by Staphylococcus(19.8%), Enterococcus(16.0%) and Bacillus(11.1%). The predominant genus among 483 isolates from commercial animal foods stored at 20℃ was Staphylococcus(23.4%), followed by Enterococcus(16.0%) and Pseudomonas(11.1%) but the predominant genera among 436 isolates from commercial animal foods stored at 30℃ was Staphylococcus(23%), followed by Enterococcus(15.4%) and Bacillus(11%).

하악 전돌증 환자의 구내 하악골 상행지 골절단술전후의 하악골 운동양상 및 저작근 근전도 변화에 관한 연

박영철,황충주,유형석,한희경 대한치과교정학회 1997 대한치과교정학회지 Vol.27 No.2

악구강계는 측두하악관절, 근육신경계, 치아, 그리고 지지조직의 복합적 구성체로 되어있어 다양한 구조를 이루고 있으며, 밀접한 생리적 관계를 유지하고 있다. 특히 하악은 저작근을 포함한 여러 근육을 운동원으로 하여 각종 기능을 수행하고 있으며, 이들 근기능의 활성도는 치근막을 비롯한 악관절과 근육 등의 여가 가지 형태의 수용기를 거쳐 말초 신경계와 중추신경계의 복잡한 경로와 기전에 의해서 조절되어지는데, 교정치료, 특히 교정을 동반한 악교정 수술시에는 이러한 악구강계의 변화와 구강내 여러감각 수용기의 변화, 근활성도의 변화가 심하게 나타나며, 이는 하악골의 기능변화를 초래하게 된다. 이에 저자는 최근 급증하는 악교정수술환자의 하악골 근육의 생리적 활성도나 하악골의 운동변화를 분석하여 보다 r객관적인 술전 및 술후의 평가기준을 제시하고자, Biopak을 이용하여 정상교합자와 하악전돌증을 주소로 내원하여 악교정수술을 시행받은 골격성 III급 부정교합자의 하악기능 양상을 총괄적으로 비교분석하여 다음과 같은 결과를 얻었다. 1. 각 군간의 근활성도 비교시 resting시에는 술전군이 정상군에 비해 더 큰 근활성도를 나타내었고, 수술후 그 측정치가 점차 감소함을 볼 수 있었다. clenching시에는 술전군의 교근과 전측두근의 근활성도가 정상군에 비해 더 감소되어 있었고 수술후 다시 증가하여 수술전과 술후 6개월군 사이에 통계적 유의차가 관찰되었다. 2. 각 근육 활성도 간의 비교시 resting시에는 전측두근의 활성도가 나머지 근육에 비해 다소 증가된 양상을 보였으나 통계적 유의차는 없었고, clenching시네는 모든 group에서 전측두근과 교근의 활성도가, swallowing시에는 악이복근의 활성도가 통계적 유의차를 보이며 크게 나타났다. 3. 하악운동범위의 비교시 전반적으로 술저군에서 제한된 운동 범위를 나타내었으며 최대개구량은 술후 6개월에, 전방 운동량은 술후 3개월에 유의성 있는 증가를 보였다. Stomatognathic system is a complex one that is composed of TMJ, neuromuscular system, teeth and connective tissue, and all its components are doing their parts to maintain their physiological relationships. Mandible, in particular, performs various functions such as mastication, speech, and deglutition; the muscular activities that determine such functions are signalled by numerous types of proprioceptors that exist in periodontal membrane, TMJ, and muscles to be controlled by complicated pathways and mechanics of peripheral and central nervous system. Orthodontic treatment, especially when accompanied by orthognathic surgery, brings dramatic changes of stomatognathic system such as intraoral proprioceptors and muscle activities and thus, changes in patterns of mandibular function result. The author tried to analyze changes in patterns of mandibular movement and physiologic activities of surrounding muscles in Skeletal Class III orthognathic surgery patients who presently show a great increase in numbers. The purpose of this study was to draw some objective guidelines in evaluation functional aspects of orthognathic surgery patients. Mandibular functional analysis using Biopak was performed for skeletal Class III prognathic patients who underwent IVRO(Intraoral Vertical Ramus Osteotmy), and the following results were obtained: 1. Resting EMG was greater in pre-surgical group than the control group, and it showed gradual decrease after the surgery. Clenching EMG of masseter and anterior temporalis of pre-surgical group was smaller than those of control group; they also increased post-surgically, and significant difference was found between pre-surgical and post-surgical(6 months) groups. 2. Resting EMG of anterior temporalis was greater than that of all the other muscles, but there was no significant difference. Clenching EMG of anterior temporalis and masseter were greater than those of the other muscles with statistical difference. In swallowing, digastric muscle showed the highest EMG with statistical significance. 3. Limited range of mandibular movement was shown in pre-surgical group. Significant increase in maximum mouth opening was observed six months post-surgically, and significant increase in protrusive movement was observed three months post-surgically.

흰쥐 하부뇌간에서의 Cholecystokinin octapeptide의 분포

오석희,박매자,조희중,주강 慶北大學校 醫科大學 1990 慶北醫大誌 Vol.31 No.3

흰쥐의 하부뇌간에서 cholecystokinin-octapeptide(CCK-8)의 분포를 관찰하기 위하여 Peroxidase-Antiperoxidase법으로 염색하여 관찰해 본 결과 다음의 많은 부위에서 CCK-8양성세포 및 양성섬유를 관찰할 수 있었다. 중뇌: 흑질, 복측피개야, n. linea rostralis, 중심회백질, n. parabrachialis colliculi posterioris, 하구 및 외측모대핵에서 CCK-8양성세포가 관찰되었고 양성섬유의 경우 각간핵, n. parabrachialis co lliculi posterioris, parabigeminal n., 하구, 외측모대핵 및 배측 봉선핵에서 관찰되었다. 후뇌: CCK-8양성세포는 n. parabrachialis lateralis, n. of group O, 고속핵, 최후야 및 삼차신경 척수로핵에서 분포하였고, 양성섬유는 교봉선핵, 교핵, n. parabrachialis lateralis, 청반핵, n. parolivaris superior, 와우신경핵, 고속핵, 미주신경배측핵, inferior olivary complex, 박속핵, 설상속핵, 삼차신경척수로핵 및 망양체의 일부등에서 존재하였다. In order to investigate the distribution of immunoreactive cholecystokinin octapeptide(CCK-8)-containing neurons in the lower brain stem of the rat, brains of the rats perfused with fixative were extirpated, fronzen sectioned and processed for Peroxidase method. The results obtained were as follows. Mid brain; CCK-8-containing cells were found in the ventral tegmental area, substantia nigra, nucleus(=n.) linea rostralis, substatia grisea centralis, n. parabrachialis lateralis, inferior colliculus and lateral lemniscus and fibers were distributed in the interpeduncular n., n. linea rostralis, ventral tegmental area, substantia nigra, superior colliculus, substantia gricea centralis, n. parabrachialis, lateralis parabigeminal n., inferior colliculus, lateral lemniscus and n. raphe dorsalis. Pons and Medulla oblongata; CCK-8-containing cells were detected in the n. parabrachialis lateralis, n. of group O, n. tractus solitarii, area postrema and n. tractus spinalis nervi trigemini, and fibers were found in n. centralis superior, pontine n., n. parabrachialis lateralis, locus coeruleus, n. parolivaris superioris, cochlea n., n. tractus solitarii, dorsal n. of vagus nerve, inferior olivary compex, n. gracilis, n. cuneatus, n. tractus spinalis nervi trigemini and reticular formation.

게 껍질을 이용한 수중의 중금속 제거

안희경,박병윤,김동석 한국환경과학회 2000 한국환경과학회지 Vol.9 No.5

In order to examine the availability and effectiveness of crab shell for the removal of heavy metals in aqueous solution, the crab shell was compared with cation exchange resin (CER), zeolite, granular activated carbon (GAC) and powdered activated carbon (PAC) on aspects of heavy metal removal capacity, rate and efficiency. In the removal of Pb, Cd and Cr, the heavy metal removal capacity of crab shell was higher than those of any other sorbents (CER, zeolite, GAC, PAC), and the order of heavy metal removal capacity was crab shell > CER > zeolite > PAC =~GAC. However, in the removal of Cu, the result of crab shell was slightly lower than that of CER. The initial heavy metal removal rate was affected by the sorts of sorbents and metals. In all heavy metals, the heavy metal removal rate of crab shell was higher than those of any other sorbents. Under the heavy metal concentration of 1.0 mmole/ℓ, the heavy metal removal efficiency of crab shell was maintained as 93∼100 %, which was much higher than those of any other sorbents.

모델 탱크내 액체의 대전전하밀도 측정에 관한 연구

고희석,박재윤,小金實成 慶南大學校 附設 工業技術硏究所 1993 硏究論文集 Vol.11 No.-

Faraday cage에 유동대전된 액체를 진공계통으로 감압, 흡인해서 전하량을 측정하는 흡인식 전하밀도 측정기(이하 흡인법이라고 한다)로 소형 탱크내의 유동대전된 전하밀도분포를 측정하고, 흡인법의 신뢰성을 분석하였다. 1. 흡인법에 의한 전하밀도 측정치는 오차가 적고, 유면상부의 전계에 비례하므로 신뢰성이 있음을 확인할 수 있었다. 2. 유량 변화에 따른 전하분포 차이는 나타나지 않았다. 3. 접지된 탱크벽으로 전하의 이동에 기인된 전계작용으로 탱크내 전하 분포는 탱크벽에 가까운 부분이 중심축보다 큰 값을 나타내었다. 4. 흡인법에 의한 측정치와 해석치를 비교 분석한 결과, 탱크축상 유층 중앙부분에서의 전하밀도는 거의 일치함을 알았다. The sucking method by which a part of charged liquid in a tank is sucked into a faraday cage using a vaccum system is used in this investigation. By using an oil circulation system which enables to control charging levels in oil, the reliability of the sucking method is examined and charge distribution in a small tank is measured. From the experiments, the results can be summarized as follows. 1. The measured charge density is directly in proportion to electric field strength at the upper side of the tank. So the charge density obtained by sucking method is reliable. 2. Any relationship between the flow rate and the charge distribution is not observed. 3. The charge density at the vicinity of the tank-wall is highter than that at the other positions because of the effect of electric field that is generated by charge moved to tank-wall itself. 4. The charge density obtained by a theoretical analysis approximately agree that measured at the middle point of the liquid region in the tank.

근원 불명 전이암의 예후인자와 생존율

원종호,박성규,홍대식,박희숙,김은석,최두호 순천향의학연구소 1999 Journal of Soonchunhyang Medical Science Vol.5 No.1

Purpose : Patients with cancer of unknown primary site represent 5% to 10% of all cancer patients. This study was to evaluate survival and prognostic factors of patients with malignancy of unknown origin. Materials and Methods : A retrospective analysis was done for one hundred and two patients with malignancy of unknown origin who were treated from January 1989 to December 1998. There were 52 male and 50 female patients. Age of patients ranged from 20 to 94 years (mean 58 years). Clinical presentation depended on the site of metastases. In cases of multiple metastatic sites, we selected the first apparent metastasis or the symptomatic one for which the patient was first seen. The three most frequent initial metastatic sites were peritoneum, lymph node, and liver. Median follow up period was 4 months(0-100 months) and survival rate measured form the time of diagnosis. Results : The two years survival rate was 13.6% with a median survival time of 4 months. The factors associated with the overall survival rate were the tumor marker CEA(p=0.0061), smoking history(p=0.0039), and histologic type(squamous cell carcinoma versus non-squamous cell carcinoma, p=0.0295). Marginal statistical difference was found according to performance status. No statistical differences were found according to sex, weight loss, initial metastatic site and numbers, primary lesion site, and treatment modality. Conclusion : Squamous cell carcinoma was associated with survival rate. In squamous cell carcinoma of unknown origin with good prognostic factor, especially cervical lymph node metastasis, we suggest an approach of extensive initial workup for staging and aggressive treatment.

금융기관 합병 공시효과 차이에 관한 연구 : 인수유형을 중심으로 Conglomerate & Non-Conglomerate Merger

조경식,박희석 대구대학교 경제경영연구소 2003 경제경영연구 Vol.2 No.1

본 연구는 그동안 국내·외 선행연구에서 드물었던 합병을 공시한 금융기관들을 대상으로 공시 전·후 인수유형별로 합병 금융기관을 두 집단으로 구분하여 누적평균초과수익률(CAR) 평균차이를 t-test를 통하여 분석하였다. 분석의 결과 다각적 합병을 한 경우 금융기관의 주주부가 비다각적 합병한 경우의 주주부 보다 평균적으로 훨씬 높은 누적평균초과수익률(CAR)을 보이는 것으로 나타났다. 그러나 두 집단간 누적평균수익률(CAR)의 평균차이가 통계적 유의성은 발견되지 않았지만, 우리나라 금융기관 합병에서 다각적 합병을 한 경우의 주주부가 증가한 이유로 첫째, 계열회사간 합병한 경우가 거의 대부분인 점 둘째, 부실화된 피합병 금융기관들이 합병을 통한 효율성 증가 기대 셋째, 다각적 합병을 통한 여러 가지 업무를 통한 시너지의 기대 등의 원인으로 보인다. This study empirically examined the effects of merger announcement in Financial Institutions, especially divided merger type prior to announcement into two group(1. conglomerate merger, 2. non-conglomerate merger). The cumulative abnormal return(CAR) surrounding the merger announcement date are used to assess whether there are mean difference two groups. The analysis(t-test) shows that, on average, the CAR of conglomerate merger realized higher than that of non-conglomerate merger, but there are statistically non- significant mean difference between two groups.

변압기의 유동대전에 대한 유속 및 유온의 영향에 관한 연구

정원용,고희석,박상현,박재윤,김정달 慶南大學校 附設 工業技術硏究所 1992 硏究論文集 Vol.10 No.-

本 硏究에서는 固體-液體 界面에서 液體가 流動할 때 발생되는 유동대전에 대한 硏究로서 大容量 變壓器내에서 絶緣油가 통과하는 通路를 모델링한 帶電 파이프를 設計·製作하고 대전 파이프내의 油路形狀에 따른 流動電流를 側定·分析하였다. 이러한 實驗으로부터 얻은 결과는 다음과 같다. 1) 流動電流는 油速의 增加에 따라 線形的으로 增加하였으며, 油溫의 增加에 따라 약 46[℃]이하에서는 增加하고 그 이상에서는 感少한다. 2) 絶緣油의 흐름이 원활하게 되도록 油路形狀을 변화시키면 流動電流는 感少한다. In this paper, the streaming electrification generated at a solid-liquid interface is studied. Electrification pipe modeled on the oil path of the high power transformer is designed and manufactured. The Streaming current is measured as a function of oil velosity, temperature at each electrification pipe. From the result of this study the following conclusions are obtained. 1) The streaming current increases linearly with increasing of oil velocity and It increases at lower temperature than 46[℃]and decreases at higher temperature than 46[℃] 2) The smoother the flow of insulating oil is the less the streaming current decreases.