• Title/Summary/Keyword: comparison method

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The Prediction of Currency Crises through Artificial Neural Network (인공신경망을 이용한 경제 위기 예측)

  • Lee, Hyoung Yong;Park, Jung Min
    • Journal of Intelligence and Information Systems
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    • v.22 no.4
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    • pp.19-43
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    • 2016
  • This study examines the causes of the Asian exchange rate crisis and compares it to the European Monetary System crisis. In 1997, emerging countries in Asia experienced financial crises. Previously in 1992, currencies in the European Monetary System had undergone the same experience. This was followed by Mexico in 1994. The objective of this paper lies in the generation of useful insights from these crises. This research presents a comparison of South Korea, United Kingdom and Mexico, and then compares three different models for prediction. Previous studies of economic crisis focused largely on the manual construction of causal models using linear techniques. However, the weakness of such models stems from the prevalence of nonlinear factors in reality. This paper uses a structural equation model to analyze the causes, followed by a neural network model to circumvent the linear model's weaknesses. The models are examined in the context of predicting exchange rates In this paper, data were quarterly ones, and Consumer Price Index, Gross Domestic Product, Interest Rate, Stock Index, Current Account, Foreign Reserves were independent variables for the prediction. However, time periods of each country's data are different. Lisrel is an emerging method and as such requires a fresh approach to financial crisis prediction model design, along with the flexibility to accommodate unexpected change. This paper indicates the neural network model has the greater prediction performance in Korea, Mexico, and United Kingdom. However, in Korea, the multiple regression shows the better performance. In Mexico, the multiple regression is almost indifferent to the Lisrel. Although Lisrel doesn't show the significant performance, the refined model is expected to show the better result. The structural model in this paper should contain the psychological factor and other invisible areas in the future work. The reason of the low hit ratio is that the alternative model in this paper uses only the financial market data. Thus, we cannot consider the other important part. Korea's hit ratio is lower than that of United Kingdom. So, there must be the other construct that affects the financial market. So does Mexico. However, the United Kingdom's financial market is more influenced and explained by the financial factors than Korea and Mexico.

A Study on Regional Revitalization Effects of Street Improvement Projects through Comparison of the Types of Citizen Participation (거리정비사업의 주민참여방식 비교를 통한 지역활성화 효과 연구)

  • Chae, Jin-Hae;Kim, Seong-Hak;Yang, Byoung-E
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.2
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    • pp.52-64
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    • 2011
  • In this study, the effects of street improvement projects in particular regions are carefully scrutinized, classified, and compared based on the types of citizen participation in those projects which are offered as one of several urban regeneration methods. The Wonju and Siheung Street Improvement Projects were selected for case studies, and in-depth interviews and a survey are conducted in both regions. As a result of in-depth interviews, the Wonju project is the community initiative type in which the community has responsibilities and decision-making abilities. On the other hand, Siheung is the community participative type in which the opinions of the community have been limited The survey targeted more than 100 local merchants, and they were asked to answer to the questions which were categorized into 21 items with a 5-point Likert scale. The analysis method was carried out through a reliability test, regression. average analysis on each group, and a T-test by SPSS 18.0. Factor analysis results show four factors: physical, partnership, community, and economical revitalization. These results reveal that the social factor can be sub-divided into a community factor and partnership factor. As a result of revitalization factors by citizen participation type, the resident initiative type is more revitalized than the resident participative type in all four factors, and shows positive responses in physical and economical revitalization factors. In particular, the physical revitalization factor has a big impact on resident satisfaction regardless of type. The community revitalization factor also has an impact on two types. It reveals that the communication is as important as physical improvement. However, it shows that no type of project affects partnership revitalization. As a result of this study, if we considered only physical improvement as project achievement, you can achieve the desired outcome without consideration of residents' participation types. Furthermore, if regional revitalization is the goal of a street improvement project, we must consider other factors such as a partnership and community revitalization.

Glycerol Steam Reforming for Hydrogen Production on Metal-ceramic Core-shell CoAl2O4@Al Composite Structures (금속-세라믹 Core-Shell CoAl2O4@Al 구조체를 적용한 불균일계 촉매의 글리세롤 수소전환 반응특성)

  • Kim, Jieun;Lee, Doohwan
    • Clean Technology
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    • v.21 no.1
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    • pp.68-75
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    • 2015
  • In this study, we investigated the structure and properties of a highly heat conductive metal-ceramic core-shell CoAl2O4@Al micro-composite for heterogeneous catalysts support. The CoAl2O4@Al was prepared by hydrothermal surface oxidation of Al metal powder, which resulted in the structure with a high heat conductive Al metal core encapsulated by a high surface area CoAl2O4 shell. For comparison, CoAl2O4 was also prepared by co-precipitation method and also utilized for a catalyst support. Rh catalysts supported on CoAl2O4@Al and CoAl2O4 were prepared by incipient wetness impregnation and characterized by N2 adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), CO chemisorption, and temperature-programmed reduction (TPR). The properties of catalysts were investigated for glycerol steam reforming reaction for hydrogen production at 550 ℃. Rh/CoAl2O4@Al exhibited about 2.8 times higher glycerol conversion turnover frequency (TOF) than Rh/CoAl2O4 due to facilitated heat transport through the core-shell structure. The CoAl2O4@Al and CoAl2O4 also showed some catalytic activities due to a partial reduction of Co on the support, and a higher catalytic activity was also found on the CoAl2O4@Al core-shell than CoAl2O4. These catalysts, however, displayed deactivation on the reaction stream due to carbon deposition on the catalysts surface.

In Vitro AChE Inhibition Tests of Insecticides Using Electric eel and Housefly AChE (전기뱀장어 및 집파리 AChE를 이용한 살충제의 In Vitro AChE 저해 시험)

  • 이시혁;이준호;조광연
    • Korean journal of applied entomology
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    • v.31 no.2
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    • pp.122-132
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    • 1992
  • Experiments were conducted to establish an in vitro AChE inhibition test system to evaluate the potency of AChE inhibition of new chemical compounds. For a fixed time inhibition test, optimal inhibition (incubation) time to evaluate their AChE inhibition potency was 10 min. for AChE inhibitors such as DFP, DDVP, and paraoxon. The concentration of new chemical compounds with an ester group for evaluation of their inhibition potency was 10 $\mu$M under 10 min. preincubation conditions. However, the stepwise inhibition test with higher concentrations seemed to be needed for other chemical compounds. For a progressive inhibition test to calculate inhibition constants such as $K_d$, $K_3$ and $K_i$, extremely low $K_d(1.3\times10-^85.6\times10^{-7})$ and $K_3$(0. 21-0.27 $min^{-1}$) were observed under lagged preincubation time (0.8-13.3 min) and low in¬hibitor concentrations $(1\times10-^92\times10-^6M)$. However, this method seemed to be useful for comparison of AChE inhibition potency among inhibitors. Differences in inhibition potency among DFP, paraoxon, and KH501 were due to the differences in $K_d$, in other words, differences in affinities between inhibitors and AChEs. Therefore, AntiChE screening should consist of two steps. The first step is to evaluate the potency of AChE inhibition based on $I_50$ valuse obtained from fixed time inhibition tests. The second step is to study inhibition patterns and characteristics of chemical compounds selected in the first step.

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A Comparison of Samplers for Aquatic Macroinvertebrate in Rice Paddies: Aquatic Net, Quadrat and Core (논에 서식하는 수서 대형무척추동물의 채집기 비교: 채집망과 방형구 및 core)

  • Kang, Hyun-Kyung;Chung, Keun
    • Korean journal of applied entomology
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    • v.49 no.4
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    • pp.313-324
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    • 2010
  • With growing interest in biodiversity in rice paddies, efficient sampling methods for quantitative evaluation of aquatic macroinvertebrates are needed because of their important role in rice paddies' food webs. For this reason, we sought a proper sampling method through comparing data collected by using aquatic net, quadrat, and core in rice paddies located in Chuncheon-si, Kangwon-do, Hongseong-gun, and Chungcheongnam-do. Because the frame of the net was rectangular and had a flat bottom, the area, sampledwith the aquatic net, was calculated by multiplying the net width by the sweeping length, All samples were taken from the space between the rows of rice plants. Twenty four taxa of macro invertebrates were collected in Chuncheon and 28 taxa in Hongseong. In Chuncheon, the number of taxa was similar among three sampling methods (17-18 taxa), but the number of individuals was different (aquatic net, $1,317/m^2$; quadrat, $1,368/m^2$; core, $1,810/m^2$. In Hongseong, the number of taxa sampled by aquatic net was the highest (aquatic net, 25 taxa; quadrat, 21 taxa; core, 16 taxa), but the core was the highest in the number of individuals (aquatic net, $1,586/m^2$; quadrat, $2,595/m^2$; core, $3,704/m^2$. The efficiency of samplers differed among taxa. Most of aquatic insect taxa were more abundant in the aquatic net, while those living on or in the paddy substratum such as Oligochaeta and Chironomidae were collected more in the quadrat sampler. To collect quantitative data for aquatic insects as well as to produce inventory of rare taxa, we suggest, based on samplers used in this study, to take quantitative samples of 6 replications from each of the edge and inner zones of a rice paddy by using an aquatic net, and to take qualitative samples both from sides of levees and the inner zone of rice paddy by using an aquatic net.

Diagnostic Accuracy and Evaluation of Myocardial Viability by Cardiac Magnetic Resonance Imaging in Acute Myocardial Infarction: A Comparison with Thallium-201 Myocardial SPECT (급성심근경색증에서의 심장자기공명영상술의 진단 정확도와 심근 생존력 평가: TI-201 심근관류 SPECT와의 비교)

  • Kim Hye-seon;Park Dong Woo;Kim Yongsoo;Kim Young-sun;Choi Yo Won;Jeon Seok Chul;Seo Heung Suk;Hahm Chang Kok;Kim Soon Kil;Ahn You hern;Choi Yoon Young;Park Choong-Ki
    • Investigative Magnetic Resonance Imaging
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    • v.7 no.2
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    • pp.100-107
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    • 2003
  • Purpose : To assess the usefulness of cardiac MR imaging (MRI) in the diagnosis of acute myocardial infarction and in the assessment of myocardial viability in comparision with T1-201 SPECT. Materials and Methods : We retrospectively studied 17 patients who complained of chest pain and dyspnea with cardiac MRI . The patients were evaluated for the presence or absence of high signal intensity on T2-weighted image (T2wI), abnormal wall motion on 2D-FIESTA, perfusion defect on Gd-DTPA enhanced T1WI, and delayed myocardial enhancement on 15-minutes delay Gd-DTPA enhanced T1WI. The results were correlated with the images on T1-201 SPECT, taken at rest and stress, through which reversibility of perfusion defect was assessed. Results : Both cardiac MRI and T1-201 SPECT proved to be useful methods for diagnosing acute myocardial infarction. In order of decreasing correspondence, T2WI, T1-201 SPECT, delayed enhancement study, and wall motion images all showed significant statistical correlation with the clinical diagnosis of myocardial infarction. Perfusion MRI, on the other hand, showed no significant statistical difference was found between T1-201 SPECT and cardiac MRI. The results on T2WI showed high accordance with those on Tl-201 SPECT, while delayed myocardial enhancement and wall motion studies showed no agreement with Tl-201 SPECT. Conclusion : Cardiac MRI is useful method for diagnosis of acute myocardiac infarction. With respect to the assessment of myocardial viability, the results obtained on cardiac MRI showed high agreement with those on Tl-201 SPECT. However, further study is necessary at this point for standardization and establishment of the methods for assessing myocardial viability on cardiac MRI.

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Comparison of Single vs Combined Modality Treatment in Locally Advanced Non-Small Cell Lung Cancer (국소 진행된 비소세포 폐암에서 복합요법과 단일요법의 비교)

  • Kim, Ae-Kyoung;Jeong, Seong-Su;Shin, Kyoung-Sang;Park, Sang-Gee;Jo, Hai-Jeong;Lee, Jong-Jin;Seo, Jee-Won;Kim, Ju-Ock;Kim, Sun-Young
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.4
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    • pp.502-512
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    • 1995
  • Background: One quarter to one third of patients with NSCLC present with primary tumors that although confined to the thorax are too extensive for surgical resection. Until resently standard treatment for these patients had been thoracic radiation, which produces tumor regression in most patients but few cures and dismal 5-year survival rate. The fact that death for most patients with stage III tumors is caused by distant metastases has promped a reevaluation of combined modality treatment approaches that include systemic chemotherapy. Therefore, we report the results observed in a study to evaluate the effect of multimodality treatment in locally advanced non-small cell lung cancer from 1/91 to 8/93 in CNUH. Method: We grouped the patients according to the treatment modalities and evaluated response rate, median survival and the effect of prognostic variables. Among 67 patients evaluated, twenty seven patients classified with group A, received cisplatin and etoposide containing combination chemotherapy alone, eighteen patients, classified with group B, received chemotherapy and radiotherapy, fifteen patients, group C, received neoadjuvant or adjuvant chemotherapy and surgery with/without radiation therapy, seven patients, group D, received only supportive care. Result: The major response rate for group A and B was 37% and 61% respectively. There was no statistically significant difference in response rate between A and B groups(p=0.97). The analysis of prognostic factors showed that differences of age, sex, pathology, blood type, smoking year, stage and ECOG performance did not related to improvement in survival. Median survival time was 8.6 months for group A, 13.4 months for group B, 19.2 months for group C, and 5.4 months for group D, respectively and there was statistically significant difference(p=0.003), suggesting that multimodality therapy was associated with signigicant improvement in survival. Subset survival analysis showed a significant therapeutic effect for earlier stage and good performance state(p=0.007, 0.009, respectively). A possible survival advantages were observed for major response groups. Conclusion: It was suggested that multimodality therapy for the management of patients who had stage III disease, has yielded good median survival and long survival for seleted patients. But, it is necessory to validate above result with further investigation in large scale and in prospective randomized trials.

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Mucociliary Clearance in the Children with Bronchial Asthma (기관지 천식 환아에서의 점액섬모 청소율(Mucociliary Clearance))

  • Lee, Myung-Hyun;Sun, Yong-Han;Nam, Seung-Gon;Koh, Young-Yull;Chung, June-Key
    • Tuberculosis and Respiratory Diseases
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    • v.43 no.2
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    • pp.173-181
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    • 1996
  • Background : Several studies have suggested that impaired mucociliary clearance plays a role in the pathophysiology of bronchial asthma. Cough productive of mucoid sputum is common, and mucous plugs in the airways are frequently observed. These clinical features are in keeping with the histologic lesions of asthma, which involve primarily the epithelial and mucous-producing structures of the conducting airways. Some studies have shown that the mucociliary clearance is impaired in adult asthma, but it has not been studied in childhood asthma. The objectives of this study were to examine whether the mucociliary clearance is impaired in childhood asthma and to estimate the degree of impairment in comparison with that of immotile cilia syndrome. Method : Thirteen children with mild stable asthma and eight patients with immotile cilia syndrome completed this study. Ten healthy children were recruited as a normal control group. The whole-lung mucociliary clearance was measured by the radioaerosol technique. Aerosols, tin colloid particles tagged with the radionuclide technetium-99m($^{99m}Tc$), were generated by means of nebulizer, and inhaled via a mouthpiece. The retention of radioactivity was measured at 30, 60, 90 and 120 minutes by gamma camera, and mucociliary clearance was calculated as percent retention at each time. Results: 1) In each subject, the percent retention decreased variably with the lapse of time. 2) The percent retention of radionuclide decreased at each time in order of normal control, bronchial asthma and immotile cilia syndrome and the percent retention of immotile cilia syndrome was significantly higher than that of normal control at each time(p<0.05). 3) At two hours, the percent retention of bronchial asthma($65.0{\pm}1.8$(SE)%) was significantly higher than that of the normal control($54.4{\pm}3.5%$, p<0.05), and significantly lower than that of immotile cilia syndrome($73.3{\pm}1.4%$, p<0.01). 4) When the percent retention was analyzed according to $PC_{20}$ in the children with bronchial asthma, they had no relationship with each other. Conclusion: Mucociliary clearance in the children with bronchial asthma was significantly lower than normal control. This finding indicates that impaired mucociliary clearance operates in childhood asthma as well, and suggests that it may be one contributing factor in the pathogenesis of asthma. The degree of impairment, however, was not so severe as immotile cilia syndrome.

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Comparison of Concurrent Chemoradiotherapy with Conventional Radiotherapy in Advanced Non-smal Cell Lung Cancer (진행된 비소세포 폐암 환자에서 Concurrent Chemoradiotherapy와 Conventional Radiotherapy의 비교)

  • Kim, Hui-Jung;Lee, Dong-Soo;Song, So-Hyang;Jung, Su-Mi;Kim, Young-Kyoon;Yoon, Se-Chul;Moon, Hwa-Sik;Song, Jeong-Sup;Park, Sung-Hak
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.3
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    • pp.493-504
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    • 1997
  • Background : Non-small cell lung cancer is one of the most frequent cause of death due to cancer in men, and its incidence among women is rapidly increasing. Although there has been a recent surge of interest in combined modality therapy for stageIII non-small cell lung cancer(NSCLC), the optimal treatment is still not well established. Thoracic irradiation has long been the gold standard for locally advanced unresectable NSCLC. However, although conventional radiotherapy(XRT) can palliate symptom and improve local control of disease, it has at most only a modest effect on survival. Recently, cisplatin(cis-diamminedichloroplatinum) has been reported to enhance the cell-killing effect of radiation For patients with unresectable NSCLC, cisplatin-based concurrent chemoradiotherapy(CCRT) had the advantage of therapeutic response over XRT alone and therapeutic side effect more commonly occurred in CCRT group in EORTC(European Organization for Research and Treatment of Cancer) and other trials. Objectives : We compared therapeutic response, compliance, and side effects between CCRT and XRT in patients with advanced NSCLC. Patients and Method : Thirty patients with biopsy-proven inoperable NSCLC were randomized to one of two treatment arms. Arm A consisted of XRT, radiotherapy for 4~6 weeks(1.8 Gy given 20~33 times, in five fractions a week), and arm B consisted of CCRT, radiotherapy for 2 weeks(3 Gy given to times, in five fractions a week), followed by 3 week rest period and then radiotherapy 2 more weeks(2.5 Gy given 10 times, in five fractions a week), combined with 6mg cisplatin per square meter, given daily before radiotherapy. We evaluate therapeutic response, compliance, change of performance status, side effects, and radiation pneumonitis by using the author's made scoring system. Results : There was no significant difference in therapeutic response and compliance. But there was a significantly lower laboratory complication and radiation pneumonitis in CCRT group (p < 0.05). There's significant negative correlation between stage and therapeutic response score in both groups(R=0.353, p < 0.05) In both groups, patients with squamous cell carcinoma had a tendency to higher therapeutic response score than those with adenocarcinoma. Conclusion : There was no difference between CCRT and XRT in respect to therapeutic response and compliance. But CCRT had a advantage of decreased side effects.

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Relation of Epidermal Growth Factor Receptor Expression to Goblet Cell Dysplasia in Diffuse Panbronchiolitis (미만성 범세기관지염에서 Epidermal Growth Factor 수용체의 발현과 배상 세포 이형성과의 관계)

  • Jung, Ki-Hwan;Lee, Seung-Heon;Kim, Byung-Gyu;Kong, Hee-Sang;Kim, Je-Hyeong;Park, Sang-Myeon;Shin, Cheol;Shim, Jae-Jeong;In, Kwang-Ho;Kim, Han-Gyum;Kang, Kyung-Ho;Ryu, Se-Hwa
    • Tuberculosis and Respiratory Diseases
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    • v.52 no.1
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    • pp.37-45
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    • 2002
  • Background: Diffuse panbronchiolitis(DPB) is a chronic inflammatory lung disease that presents as coughing, copious sputum, exertional dyspnea, which progresses to bronchiectasis. The pathogenesis of bronchiectasis is controlled by inflammatory mediators, which are closely related to mucus hypersecretion, goblet cell dysplasia. In recent studies, the epidermal growth factor receptor(EGFR) system was reported to be associated with this process. It was hypothesized that a relationship exists between goblet cell dysplasia, EGFR expression, and inflammatory mediators produced by neutrophil. Method: Alcian blue/periodic acid -Schiff(AB/PAS) stain, MUC5AC, EGFR, CD16 immunohistochemical stain were examined to investigate a role for the EGFR system in a mucus hypersecretion in DPB using the lung biopsy specimens from 13 DPB patients and 6 controls. Results : In the DPB group, the AB/PAS and MUC5AC -stained areas were $8.31{\pm}3.36%$, $11.46{\pm}4.68%$, respectively. In the control group, the AB/PAS- and MUC5AC-stained areas were $50.5{\pm}5.77%$, $53.3%{\pm}6.67%$, which was significantly larger than in the DPB group (each comparison, p<0.05). The percentage of EGFR expression was $9.54{\pm}4.95%$ in the DPB group, but zero in of the control group. The extent of neutrophilic infiltration was $71.92{\pm}3.71$/5HPF in the DPB group and $45.0{\pm}5.73$/5HPF in the control group, which was statistically significant(p=0.002). Conclusion: The EGFR system is highly related to goblet cell dysplasia, mucus hypersecretion and neutrophilic inflammation in DPB.