• Title/Summary/Keyword: long-term test

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The Effect of Contamination of Ion Source on Ionic Current of Quadrupole Mass Spectrometer (사중극 질량 분석기의 이온소스 오염이 이온전류에 미치는 영향)

  • Lee, K.C.;Park, C.J.;Kim, J.T.;Oh, E.S.;Hong, K.S.;Hong, S.S.;Lim, I.T.;Yun, J.Y.;Kang, S.W.;Shin, Y.H.
    • Journal of the Korean Vacuum Society
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    • v.18 no.3
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    • pp.197-202
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    • 2009
  • The long term stability of ion current of QMS has been one of key parameters for monitoring gas process in vacuum. The time dependence of ionic current was monitored while the pressure of nitrogen gas was kept at a fixed pressure by introducing the gas into vacuum chamber. The chamber was evacuated to ${\sim}3{\times}10^{-9}\;Torr$ to reduce background signals before the measurement. Two ion sources were tested; one had brownish or black color due to gas contamination and the other one was new, i.e. cleaner. At a nitrogen pressure of $1{\times}10^{-5}\;Torr$, the ionic currents measured by the contaminated ion source decreased faster with time. The decrease rate was respectively ${\sim}46%$ for cleaner one and ${\sim}84%$ for contaminated one after ${\sim}5.5%$ hours. In order to test the effect of filament material on the ion current decrease, we fabricated a tungsten(W) filament which consisted of two parts; one half was made of W and the other was coated with yttria. The similar decrease of ionic currents were shown for the two types of filaments, indicating that slight change of temperature of filament due to material difference i.e. baking effect could not improve the origin of ionic current decrease. Overall the decreasing rate of ionic current is more closely associated with contaminated ion source of QMS rather than its filament materials.

The Eradication of Helicobacter pylori in the Duodenal Ulcer in Children and the Duodenal Recurrence (소아 십이지장궤양에서의 H. pylori 박멸과 궤양재발에 대한 연구)

  • Choe, Yon-Ho;Ko, Jae-Sung;Kim, Soon-Yeong;Yoo, Young-Mee;Seo, Jeong-Kee
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.1 no.1
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    • pp.30-36
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    • 1998
  • Purpose: It is well known that duodenal ulcer disease does not relapse if H. pylori is cleared from the gastric mucosa. Little is known about the recurrence of duodenal ulcer in children. The purpose of this study was to evaluate the effect of the eradication of H. pylori in duodenal ulcer in children upon the duodenal ulcer recurrence. Methods: 105 patients (M:F=78:27) diagnosed as duodenal ulcer by endoscopy in 1987~1995 were reviewed clinically, and were parted into two groups. The two treatment groups were ranitidine/antacid (RAN/ANT) and ranitidine/amoxicillin/denol (RAN/AMX/D). The latter was for H. pylori-positive children with duodenal ulcer who were diagnosed by serology and/or antral biopsies for histology, culture, and urease testing. The recurrence rates were compared between the two groups. Results: 1) 30 patients with primary duodenal ulcer underwent endoscopy for H. pylori and 27 (90.0%) of them were positive for H. pylori. 2) 27 of H. pylori-positive children received RAN/AMX/D. 23(85.2%) of them showed cure of duodenal ulcer and eradication of H. pylori. 3) The duodenal ulcer recurrence rate in RAN/ANT group was 65.3% and the rate in RAN/AMX/D was 4.3% by a year. Conclusions: There is a strong correlation between the duodenal ulceration and H. pylori infection in children, and the eradication of H. pylori in duodenal ulcer patients reduces the recurrence of the ulcer. Because of the low incidence of duodenal ulcers in children, a multicenter prospective study is required to determine the effect of treating H. pylori infetion on the long term natural history of duodenal ulcer disease.

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A Study on Change in Cement Mortar Characteristics under Carbonation Based on Tests for Hydration and Porosity (수화물 및 공극률 관측 실험을 통한 시멘트모르타르의 탄산화 특성 변화에 대한 연구)

  • Kwon, Seung-Jun;Song, Ha-Won;Park, Sang-Soon
    • Journal of the Korea Concrete Institute
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    • v.19 no.5
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    • pp.613-621
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    • 2007
  • Due to the increasing significance of durability, much researches on carbonation, one of the major deterioration phenomena are carried out. However, conventional researches based on fully hardened concrete are focused on prediction of carbonation depth and they sometimes cause errors. In contrast with steel members, behaviors in early-aged concrete such as porosity and hydrates (calcium hydroxide) are very important and may be changed under carbonation process. Because transportation of deteriorating factors is mainly dependent on porosity and saturation, it is desirable to consider these changes in behaviors in early-aged concrete under carbonation for reasonable analysis of durability in long term exposure or combined deterioration. As for porosity, unless the decrease in $CO_2$ diffusion due to change in porosity is considered, the results from the prediction is overestimated. The carbonation depth and characteristics of pore water are mainly determined by amount of calcium hydroxide, and bound chloride content in carbonated concrete is also affected. So Analysis based on test for hydration and porosity is recently carried out for evaluation of carbonation characteristics. In this study, changes in porosity and hydrate $(Ca(OH)_2)$ under carbonation process are performed through the tests. Mercury Intrusion Porosimetry (MIP) for changed porosity, Thermogravimetric Analysis (TGA) for amount of $(Ca(OH)_2)$ are carried out respectively and analysis technique for porosity and hydrates under carbonation is developed utilizing modeling for behavior in early-aged concrete such as multi component hydration heat model (MCHHM) and micro pore structure formation model (MPSFM). The results from developed technique is in reasonable agreement with experimental data, respectively and they are evaluated to be used for analysis of chloride behavior in carbonated concrete.

Risk Factor's Affecting long-term Outcome of Alport syndrome (Alport 증후군의 예후와 관련된 위험요인 분석)

  • Byun Ji-Yoon;Baek Seoung-Yon;Lee Young-Mock;Kim Ji-Hong;Lee Jae Seung;Kim Pyung-Kil;Hong Soon-Won;Jeong Hyeon-Joo;Kim Soon-Il;Kim Yu-Seun;Park Ki-Il
    • Childhood Kidney Diseases
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    • v.5 no.2
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    • pp.164-175
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    • 2001
  • Purpose : Alport syndrome is a hereditary nephrotic disease characterized by progressive nephrotic symptom, sensorineural hearing loss, ophthalmic abnormality, typical microscopic findings, and familial occurrence. In this study, we tried to find the risk factors related with its prognosis by taking a close observation on clinical symptoms of children with Alport syndrome reviewing retrospectively. Materials & methods : We chose children diagnosed as Alport syndrome in renal biopsy during 20 years(from 1980, Jan. until 1999, Dec.) who could receive follow up studies in tile department of pediatrics. They were divided into two groups by comparing renal function at the time of diagnosis and at current status. We compared several clinical aspects in them, and applied nonparametric test for statistical analysis. Results : The sex ratio(male:female) of 24 children was 3:1. The most common clinical symptom presented at their first visit was gross hematuria. Among those 24 children, 11 cases($46\%$) of progressing into chronic renal failure(Group II) were observed. Hypertension, proteinuria and edema were seen much frequently in group II. The level of serum protein, albumin, and creatinine clearance were decreased while BUN, creatinine were relatively increased. All the results were statistically significant. Conclusion Clinically significant risk factors related to prognosis in Alport syndrome were the presence of hypertension, edema, and proteinuria at the time of diagnosis. Also, the level of serum protein, albumin, BUN, creatinine, and glomerular filtration rate were proved to be important factors in predicting prognosis. We believe that studies on these possible risk factors would be of great help in treating and predicting prognosis of children suffering with Alport syndrome. (J Korean Soc Pediatr Nephrol 2001;5 : 164-75)

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Effects of Postharvest 1-MCP Treatment, Storage Method, and Shelf Temperature on Quality Changes of 'Gamhong' Apples during Export Simulation (수확후 1-MCP 처리, 저장 방법 및 현지 유통온도가 모의수출 '감홍' 사과의 품질에 미치는 영향 분석)

  • Park, Youn-Moon;Yoon, Tae-Myung
    • Horticultural Science & Technology
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    • v.30 no.6
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    • pp.725-733
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    • 2012
  • Effects of postharvest 1-methylcyclopropene (1-MCP) treatment, controlled atmosphere (CA) storage, and shelf temperature on quality of 'Gamhong' apples were analyzed during export simulation. Fruits were harvested at the optimum maturity for long-term storage, treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP for 16 hours, and then stored for 6 months under air and CA conditions at $0^{\circ}C$. Poststorage export procedure was performed by applying additional 2-week refrigerated storage and 7-day shelf-life test at 7 and $20^{\circ}C$, which simulated container shipment and local distribution, respectively. After storage and during export simulation, rates of respiration and ethylene evolution were significantly lower in 1-MCP treated and CA-stored apples. For the reduction of respiration, CA storage was more effective than 1-MCP treatment. Soluble solids content was maintained higher in 1-MCP treated apples, while titratable acidity was maintained better both in the 1-MCP treated and CA-stored apples. Effects of 1-MCP treatment and CA storage were highly significant in maintaining flesh firmness and sensory texture ratings. Additive effects from combined application of 1-MCP treatment and CA storage were occasionally observed. Shelf temperature during the local distribution simulation seemed not to significantly influence quality changes only showing limited effects on flesh firmness. Overall results suggest that storage potential of 'Gamhong' apples is shorter than 4 months in control fruit under refrigerated air conditions, whereas the potential can be extended to longer than 6 months by 1-MCP treatment and CA storage. Postharvest program should be provided considering the time of export, i.e. period of storage, and duration of local distribution.

Availability of Heavy Metals in Soils with Different Characteristics and Controversial Points for Analytical Methods of Soil Contamination in Korea (토양특성별 중금속 유효도와 토양오염 평가방법의 개선점)

  • Jung, Goo-Bok;Kim, Won-Il;Lee, Jong-Sik;Shin, Joung-Du;Kim, Jin-Ho;Yun, Sun-Gang
    • Korean Journal of Environmental Agriculture
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    • v.24 no.2
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    • pp.106-116
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    • 2005
  • This experiment was conducted to investigate available extraction capacity and potential mobility of heavy metal according to the distribution property and contamination level of heavy metals in soils and to suggest a reform measure of soil environment assessment methodology applied with soil quality and the official soil heavy metal test methods in domestic and foreign countries. The soils were collected from the natural forest paddy with long-term application of same type fertilizer, and paddies near metal mine and industrial complex. The post-treatment methods of soil were partial extraction, acid digestion and sequential extraction methods. For the heavy metal contents with different soil properties, it was shown that their natural forest and paddy soil were slightly low and similar to the general paddy soil, while their paddies near metal mine and industrial complex were higher than the standard level of Soil Environment Protection Act. Heavy metal concentrations in the soils with different soil properties had difference between $HNO_3\;and\;HNO_3+HCl$ extractant by US-EPA 3051a method. There were highly significant positive relationships in both two methods. It was appeared that the higher extractable concentration ratio with 0.1N-HCl to total heavy metal content with $HNO_3+HCl$ extractant the greater total heavy metal content. There were highly significant positive correlationship between total heavy metal content and extractable content with 0.1N-HCl. For extractable capacity of soil extractable solution compared to the total heavy metal content it was appeared that it extractable method with 0.1N-HCl was higher than those with EDTA and DTPA. In extractable ratio with 0.1N-HCl in the contaminated paddy soils near mine and industrial complex, it was shown that the lower soil pH, the higher total heavy metal content. The order of a potential mobility coefficient by distribution of heavy metal content with ie different typies in the soil was Cd>Ni>Zn>Cu>Pb. It could be known that contamination characteristics of heavy metals with different types of soils were affected by different heavy metal components, contamination degree and soil chemical properties, and heavy metal concentration with different extractable methods had great variations with adjacent environment. To be compared with assessment methodology of soil environment impact at domestic and foreign countries with our results, it might be considered that there was necessary to make a single analysis method based on total heavy metal content with environmental overloading concept because of various analysis methods for total heavy metal content and present analysis method with great variation according to soil environment. In spite of showing higher concentration of heavy metal with acidic digestion than the extractable method, it might be considered that there is need to be adjusted the national standard of soil heavy metal contamination.

Clinical Features of Benign Infantile Convulsions with Gastroenteritis (위장관염과 동반된 양성 영아 경련의 임상적 고찰)

  • Lee, Jung Sun;Kwon, Hae Oak;Jee, Young Mee;Chae, Kyu Young
    • Clinical and Experimental Pediatrics
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    • v.48 no.7
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    • pp.753-759
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    • 2005
  • Purpose : This study was performed to characterize clinical features of benign convulsions with gastroenteritis(CwG) in infants. Methods : We reviewed clinical features of 67 episodes in 64 patients with afebrile seizure accompanied gastroenteritis admitted to Dept. of Pediatrics Bundang CHA hospital from January 2001 to June 2004. Patients with meningitis, encephalitis/encephalopathy or apparent history of epilepsy were excluded. Results : There were 32 boys and 35 girls. The age of onset ranged from 1 to 42 months($18.5{\pm}6.1$ months). The number of children admitted to the hospital with acute gastroenteritis was 2,887 in the same period. The percentage of patients with CwG was 2.3. Seizure type was exclusively generalized tonic or tonic-clonic seizure. The average number of seizures during a single episode was 3.1 (range, 1-13). Two or more seizures occurred in 53(79.1%) of the 67 episodes. Antiepileptic drugs were administered for 42 episodes. Seizure did not cease after the administration of one kind of antiepileptic drug in 23 episodes(54.7%). The seizures were rather refractory to initial antiepileptic treatment. There were no abnormalities in serum biochemistry test including glucose and electrolytes. Cerebrospinal fluid was normal in all 54 episodes. Stool cultures were negative in 49 episodes. Rotavirus was positive in stools in 51(82.3%) of 62 episodes. Norovirus was positive in stools in 2 episodes and astrovirus in 1 of 18 episodes. CT and/or MRI were performed in 15 cases and demonstrated no neuroradiologic abnormalities. Of 73 Interictal EEG, initial 24 cases showed occasional spike or sharp wave discharges from the mid-line area during stage I-II sleep, which were apparently differentiated from vertex sharp transient or K-complexes. The mean follow-up period was 5.7 months(1-36 months). Three patients experienced a recurrence of CwG, but all patients exhibited normal psychomotor development at the last follow-up. Conclusion : Afebrile infantile convulsions with gastroenteritis are brief generalized seizure in cluster with normal laboratory findings and good prognosis. Therefore CwG is likely to be categorized as situation-related seizure of special syndrome. Recognition of this entity should lead to assurance of the parents and long-term anticonvulsant therapy is not usually warranted.

Follow-up of children with isolated microscopic hematuria detected in a mass school urine screening test (학교집단소변검사에서 발견된 단독 현미경적 혈뇨의 추적 관찰)

  • Yum, Mi-sun;Yoon, Hoe Soo;Lee, Joo Hoon;Hahn, Hyewon;Park, Young Seo
    • Clinical and Experimental Pediatrics
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    • v.49 no.1
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    • pp.82-86
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    • 2006
  • Purpose : The isolated microscopic hematuria is the most common abnormality detected by school urinary screening, but there is no consensus about the range of investigations and long-term outcomes of isolated hematuria in children yet. This study aims to elucidate the prognosis of hematuria and the range of diagnostic studies by follow-up results. Methods : Students with isolated hematuria who were referred to the Department of Pediatrics, Asan Medical Center from Aug. 1990 to Feb. 2004 were analysed retrospectively. Cases that presented Through significant proteinuria(>250 mg/day), other symptoms of nephritis or renal dysfunction (creatinine clearance <85 mL/min/$1.73m^2$) were excluded. Follow-up was done every six months with checking urinalysis, serum creatinine, protein and albumin. When albuminuria was detected, 24 hour urine protein was checked. Renal biopsy was done when urine protein was over 500 mg/day. Results : A total of 331 students were enrolled in this study. There were 157 males and 174 females. The mean age at presentation was $9.9{\pm}2.3$ years(7-15 years) and mean follow-up period was $2.2{\pm}1.6$ years(1-10 years). Seventy five(22.7 percent) patients showed the resolution of microscopic hematuria. The mean resolution period was $2.6{\pm}1.7$ years(1-8 years). Eight(2.4 percent) patients developed significant proteinuria and renal biopsy was done in four of them. Two cases of mild IgA nephropathy and two of minimal change were detected. None of them developed hypertension. At the end of the follow-up, renal function had remained stable in all subsets of patients. Conclusion : The prognosis of isolated microscopic hematuria was good. This study suggests that invasive studies including renal biopsy are not necessary and a regular follow-up of urinalysis is enough for children with isolated microscopic hematuria.

Improving Bidirectional LSTM-CRF model Of Sequence Tagging by using Ontology knowledge based feature (온톨로지 지식 기반 특성치를 활용한 Bidirectional LSTM-CRF 모델의 시퀀스 태깅 성능 향상에 관한 연구)

  • Jin, Seunghee;Jang, Heewon;Kim, Wooju
    • Journal of Intelligence and Information Systems
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    • v.24 no.1
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    • pp.253-266
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    • 2018
  • This paper proposes a methodology applying sequence tagging methodology to improve the performance of NER(Named Entity Recognition) used in QA system. In order to retrieve the correct answers stored in the database, it is necessary to switch the user's query into a language of the database such as SQL(Structured Query Language). Then, the computer can recognize the language of the user. This is the process of identifying the class or data name contained in the database. The method of retrieving the words contained in the query in the existing database and recognizing the object does not identify the homophone and the word phrases because it does not consider the context of the user's query. If there are multiple search results, all of them are returned as a result, so there can be many interpretations on the query and the time complexity for the calculation becomes large. To overcome these, this study aims to solve this problem by reflecting the contextual meaning of the query using Bidirectional LSTM-CRF. Also we tried to solve the disadvantages of the neural network model which can't identify the untrained words by using ontology knowledge based feature. Experiments were conducted on the ontology knowledge base of music domain and the performance was evaluated. In order to accurately evaluate the performance of the L-Bidirectional LSTM-CRF proposed in this study, we experimented with converting the words included in the learned query into untrained words in order to test whether the words were included in the database but correctly identified the untrained words. As a result, it was possible to recognize objects considering the context and can recognize the untrained words without re-training the L-Bidirectional LSTM-CRF mode, and it is confirmed that the performance of the object recognition as a whole is improved.

Cost Analysis of Home Nursing Care Patients in Rural Hospital (농촌 지역 중소병원의 가정간호사업소 등록환자의 방문비용분석)

  • Kim, Jin-Soon;Kum, Ran;HwangBo, Soo-Ja
    • Journal of agricultural medicine and community health
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    • v.24 no.1
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    • pp.91-101
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    • 1999
  • The home nursing care system is an integral part of the health care delivery system in order to meet the various needs of consummer, in particular, early discharge patient from the hospital, patient with long term care needed and the elderly. To find out the cost of home nursing care services, the home nursing care records of patients registered by home nursing care units established in public hospital with 150beds during the period of 1996 - 1997 were analyzed. The subjects were 102patients, 45 of male patients and 57 of female patients, those who live in a rural area in Kymiggi - Do The results obtained are as follows : 1. The male patients accounted for 44.1% of the total, with 45cases : group aged 60 years and more was the largest group, accounting for 79.5%. 2. The most frequent disease revealed was the osteoporosis which constitute 35.3% of the total registered patients, followed, in order, by malignant tumor, cerebrovascular disease. 3. It revealed that the cost per visit for the male was 47,764won ; the female, 46,078 won per visit. Noteworthy the cost per visit was high in the older patient. It was clearly that the gender, years of age and the cost per visit were statistically significant at 0.01 level and 0.05 level. 4. The cost per visit for the non complicated disease was slightly higher than the complicated disease, but it is not statistically significant, the cost per visit by type of disease varied, the cost per visit for COPD was the highest, followed, in order, by in malignant tumor, cancer, diabetes, osteoporosis etc. 5. It revealed that home nursing care cost for a eligible disease for home nursing care was less than the cost for hospitalization of the same disease, therefore, we expect that the home nursing care is cost efficiency. In conclusion, the home nursing care costs are needed to analyze further in comparison with the hospitalization costs for a certain disease.

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