• Title/Summary/Keyword: 예측 확률

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Clinical Experience of Three Dimensional Conformal Radiation Therapy for Non-Small Cell Lung Cancer (비소세포성 폐암에서 3차원 입체조형 방사선 치료 성적)

  • Choi Eun Kyung;Lee Byong Yong;Kang One Chul;Nho Young Ju;Chung Weon Kuu;Ahn Seung Do;Kim Jong Hoon;Chang Hyesook
    • Radiation Oncology Journal
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    • v.16 no.3
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    • pp.265-274
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    • 1998
  • Purpose : This prospective study has been conducted to assess the value of three dimensional conformal radiation therapy (3DCRT) for lung cancer and to determine its potential advantage over current treatment approaches. Specific aims of this study were to 1) find the most ideal 3DCRT technique 2) establish the maximum tolerance dose that can be delivered with 3DCRT and 3) identify patients at risk for development of radiation pneumonitis. Materials and Methods : Beginning in Nov. 1994, 95 patients with inoperable non-small cell lung cancer (stage I; 4, stage II; 1, stage IIIa; 14, stage IIIb; 76) were entered onto this 3D conformal trial Areas of known disease and elective nodal areas were initially treated to 45 Gy and then using 3DCRT technique 65 to 70 Gy of total dose were delivered to the gross disease. Sixty nine patients received 65 Gy of total dose and 26 received 70 Gy Seventy eight patients (82.1$\%$) also received concurrent MVP chemotherapy. 3DCRT plans were compared with 2D plans to assess the adequacy of dose delivery to target volume, dose volume histograms for normal tissue, and normal tissue complication Probabilities (NTCP). Results : Most of plans (78/95) were composed of non-coplanar multiple (4-8) fields. Coplanar segmented conformal therapy was used in 17 pateints, choosing the proper gantry angle which minimize normal lung exposure in each segment. 3DCRT gave the full dose to nearly 100$\%$ of the gross disease target volume in all patients. The mean NTCP for ipsilateral lung with 3DCRT (range; 0.17-0.43) was 68$\%$ of the mean NTCP with 2D treatment planning (range; 0.27-0.66). DVH analysis for heart showed that irradiated volume of heart could be significantly reduced by non-coplanar 3D approach especially in the case of left lower lobe lesion. Of 95 patients evaluable for response, 75 (79$\%$), showed major response including 25 (26$\%$) with complete responses and 50 (53$\%$) with partial responses. One and two rear overall survivals of stage III patients were 62.6$\%$ and 35.2$\%$ respectively. Twenty percent (19/95) of patients had pneumonitis; Eight patients had grade 1 pneumonitis and 11 other patients had grade 2. Comparison of the average of NTCP for lung showed a significant difference between patients with and without radiation pneumonitis. Average NTCP for Patients without complication was 62$\%$ of those with complications. Conclusions : This study showed that non-coplanar multiple fields (4-8) may be one of the ideal plans for 3DCRT for lung cancer. It also suggested that 3DCRT may provide superior delivery of high dose radiation with reduced risk to normal tissue and that NTCP can be used as a guideline for the dose escalation.

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A Study on Industries's Leading at the Stock Market in Korea - Gradual Diffusion of Information and Cross-Asset Return Predictability- (산업의 주식시장 선행성에 관한 실증분석 - 자산간 수익률 예측 가능성 -)

  • Kim Jong-Kwon
    • Proceedings of the Safety Management and Science Conference
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    • 2004.11a
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    • pp.355-380
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    • 2004
  • I test the hypothesis that the gradual diffusion of information across asset markets leads to cross-asset return predictability in Korea. Using thirty-six industry portfolios and the broad market index as our test assets, I establish several key results. First, a number of industries such as semiconductor, electronics, metal, and petroleum lead the stock market by up to one month. In contrast, the market, which is widely followed, only leads a few industries. Importantly, an industry's ability to lead the market is correlated with its propensity to forecast various indicators of economic activity such as industrial production growth. Consistent with our hypothesis, these findings indicate that the market reacts with a delay to information in industry returns about its fundamentals because information diffuses only gradually across asset markets. Traditional theories of asset pricing assume that investors have unlimited information-processing capacity. However, this assumption does not hold for many traders, even the most sophisticated ones. Many economists recognize that investors are better characterized as being only boundedly rational(see Shiller(2000), Sims(2201)). Even from casual observation, few traders can pay attention to all sources of information much less understand their impact on the prices of assets that they trade. Indeed, a large literature in psychology documents the extent to which even attention is a precious cognitive resource(see, eg., Kahneman(1973), Nisbett and Ross(1980), Fiske and Taylor(1991)). A number of papers have explored the implications of limited information- processing capacity for asset prices. I will review this literature in Section II. For instance, Merton(1987) develops a static model of multiple stocks in which investors only have information about a limited number of stocks and only trade those that they have information about. Related models of limited market participation include brennan(1975) and Allen and Gale(1994). As a result, stocks that are less recognized by investors have a smaller investor base(neglected stocks) and trade at a greater discount because of limited risk sharing. More recently, Hong and Stein(1999) develop a dynamic model of a single asset in which information gradually diffuses across the investment public and investors are unable to perform the rational expectations trick of extracting information from prices. Hong and Stein(1999). My hypothesis is that the gradual diffusion of information across asset markets leads to cross-asset return predictability. This hypothesis relies on two key assumptions. The first is that valuable information that originates in one asset reaches investors in other markets only with a lag, i.e. news travels slowly across markets. The second assumption is that because of limited information-processing capacity, many (though not necessarily all) investors may not pay attention or be able to extract the information from the asset prices of markets that they do not participate in. These two assumptions taken together leads to cross-asset return predictability. My hypothesis would appear to be a very plausible one for a few reasons. To begin with, as pointed out by Merton(1987) and the subsequent literature on segmented markets and limited market participation, few investors trade all assets. Put another way, limited participation is a pervasive feature of financial markets. Indeed, even among equity money managers, there is specialization along industries such as sector or market timing funds. Some reasons for this limited market participation include tax, regulatory or liquidity constraints. More plausibly, investors have to specialize because they have their hands full trying to understand the markets that they do participate in

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Prediction of Salvaged Myocardium in Patients with Acute Myocardial Infarction after Primary Percutaneous Coronary Angioplasty using early Thallium-201 Redistribution Myocardial Perfusion Imaging (급성심근경색증의 일차적 관동맥성형술 후 조기 Tl-201 재분포영상을 이용한 구조심근 예측)

  • Choi, Joon-Young;Yang, You-Jung;Choi, Seung-Jin;Yeo, Jeong-Seok;Park, Seong-Wook;Song, Jae-Kwan;Moon, Dae-Hyuk
    • The Korean Journal of Nuclear Medicine
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    • v.37 no.4
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    • pp.219-228
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    • 2003
  • Purpose: The amount of salvaged myocardium is an important prognostic factor in patients with acute myocardial infarction (MI). We investigated if early Tl-201 SPECT imaging could be used to predict the salvaged myocardium and functional recovery in acute MI after primary PTCA. Materials and Methods: In 36 patients with first acute MI treated with primary PTCA, serial echocardiography and Tl-201 SPECT imaging ($5.8{\pm}2.1$ days after PTDA) were performed. Regional wall motion and perfusion were quantified with on 16-segment myocardial model with 5-point and 4-point scaling system, respectively. Results: Wall motion was improved in 78 of the 212 dyssynergic segments on 1 month follow-up echocardiography and 97 on 7 months follow-up echocardiography, which were proved to be salvaged myocardium. The areas under receiver operating characteristic curves of Tl-201 perfusion score for detecting salvaged myocardial segments were 0.79 for 1 month follow-up and 0.83 for 7 months follow-up. The sensitivity and specificity of Tl-201 redistribution images with optimum cutoff of 40% of peak thallium activity for detecting salvaged myocardium were 84.6% and 55.2% for 1 month follow-up, and 87.6% and 64.3% for 7 months follow-up, respectively. There was a linear relationship between the percentage of peak thallium activity on early redistribution imaging and the likelihood of segmental functional improvement 7 months after reperfusion. Conclusion: Tl-201 myocardial perfusion SPECT imaging performed early within 10 days after reperfusion can be used to predict the salvaged myocardium and functional recovery with high sensitivity during the 7 months following primary PTCA in patients with acute MI.

Extension Method of Association Rules Using Social Network Analysis (사회연결망 분석을 활용한 연관규칙 확장기법)

  • Lee, Dongwon
    • Journal of Intelligence and Information Systems
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    • v.23 no.4
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    • pp.111-126
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    • 2017
  • Recommender systems based on association rule mining significantly contribute to seller's sales by reducing consumers' time to search for products that they want. Recommendations based on the frequency of transactions such as orders can effectively screen out the products that are statistically marketable among multiple products. A product with a high possibility of sales, however, can be omitted from the recommendation if it records insufficient number of transactions at the beginning of the sale. Products missing from the associated recommendations may lose the chance of exposure to consumers, which leads to a decline in the number of transactions. In turn, diminished transactions may create a vicious circle of lost opportunity to be recommended. Thus, initial sales are likely to remain stagnant for a certain period of time. Products that are susceptible to fashion or seasonality, such as clothing, may be greatly affected. This study was aimed at expanding association rules to include into the list of recommendations those products whose initial trading frequency of transactions is low despite the possibility of high sales. The particular purpose is to predict the strength of the direct connection of two unconnected items through the properties of the paths located between them. An association between two items revealed in transactions can be interpreted as the interaction between them, which can be expressed as a link in a social network whose nodes are items. The first step calculates the centralities of the nodes in the middle of the paths that indirectly connect the two nodes without direct connection. The next step identifies the number of the paths and the shortest among them. These extracts are used as independent variables in the regression analysis to predict future connection strength between the nodes. The strength of the connection between the two nodes of the model, which is defined by the number of nodes between the two nodes, is measured after a certain period of time. The regression analysis results confirm that the number of paths between the two products, the distance of the shortest path, and the number of neighboring items connected to the products are significantly related to their potential strength. This study used actual order transaction data collected for three months from February to April in 2016 from an online commerce company. To reduce the complexity of analytics as the scale of the network grows, the analysis was performed only on miscellaneous goods. Two consecutively purchased items were chosen from each customer's transactions to obtain a pair of antecedent and consequent, which secures a link needed for constituting a social network. The direction of the link was determined in the order in which the goods were purchased. Except for the last ten days of the data collection period, the social network of associated items was built for the extraction of independent variables. The model predicts the number of links to be connected in the next ten days from the explanatory variables. Of the 5,711 previously unconnected links, 611 were newly connected for the last ten days. Through experiments, the proposed model demonstrated excellent predictions. Of the 571 links that the proposed model predicts, 269 were confirmed to have been connected. This is 4.4 times more than the average of 61, which can be found without any prediction model. This study is expected to be useful regarding industries whose new products launch quickly with short life cycles, since their exposure time is critical. Also, it can be used to detect diseases that are rarely found in the early stages of medical treatment because of the low incidence of outbreaks. Since the complexity of the social networking analysis is sensitive to the number of nodes and links that make up the network, this study was conducted in a particular category of miscellaneous goods. Future research should consider that this condition may limit the opportunity to detect unexpected associations between products belonging to different categories of classification.

A Study on the Improvement of Recommendation Accuracy by Using Category Association Rule Mining (카테고리 연관 규칙 마이닝을 활용한 추천 정확도 향상 기법)

  • Lee, Dongwon
    • Journal of Intelligence and Information Systems
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    • v.26 no.2
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    • pp.27-42
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    • 2020
  • Traditional companies with offline stores were unable to secure large display space due to the problems of cost. This limitation inevitably allowed limited kinds of products to be displayed on the shelves, which resulted in consumers being deprived of the opportunity to experience various items. Taking advantage of the virtual space called the Internet, online shopping goes beyond the limits of limitations in physical space of offline shopping and is now able to display numerous products on web pages that can satisfy consumers with a variety of needs. Paradoxically, however, this can also cause consumers to experience the difficulty of comparing and evaluating too many alternatives in their purchase decision-making process. As an effort to address this side effect, various kinds of consumer's purchase decision support systems have been studied, such as keyword-based item search service and recommender systems. These systems can reduce search time for items, prevent consumer from leaving while browsing, and contribute to the seller's increased sales. Among those systems, recommender systems based on association rule mining techniques can effectively detect interrelated products from transaction data such as orders. The association between products obtained by statistical analysis provides clues to predicting how interested consumers will be in another product. However, since its algorithm is based on the number of transactions, products not sold enough so far in the early days of launch may not be included in the list of recommendations even though they are highly likely to be sold. Such missing items may not have sufficient opportunities to be exposed to consumers to record sufficient sales, and then fall into a vicious cycle of a vicious cycle of declining sales and omission in the recommendation list. This situation is an inevitable outcome in situations in which recommendations are made based on past transaction histories, rather than on determining potential future sales possibilities. This study started with the idea that reflecting the means by which this potential possibility can be identified indirectly would help to select highly recommended products. In the light of the fact that the attributes of a product affect the consumer's purchasing decisions, this study was conducted to reflect them in the recommender systems. In other words, consumers who visit a product page have shown interest in the attributes of the product and would be also interested in other products with the same attributes. On such assumption, based on these attributes, the recommender system can select recommended products that can show a higher acceptance rate. Given that a category is one of the main attributes of a product, it can be a good indicator of not only direct associations between two items but also potential associations that have yet to be revealed. Based on this idea, the study devised a recommender system that reflects not only associations between products but also categories. Through regression analysis, two kinds of associations were combined to form a model that could predict the hit rate of recommendation. To evaluate the performance of the proposed model, another regression model was also developed based only on associations between products. Comparative experiments were designed to be similar to the environment in which products are actually recommended in online shopping malls. First, the association rules for all possible combinations of antecedent and consequent items were generated from the order data. Then, hit rates for each of the associated rules were predicted from the support and confidence that are calculated by each of the models. The comparative experiments using order data collected from an online shopping mall show that the recommendation accuracy can be improved by further reflecting not only the association between products but also categories in the recommendation of related products. The proposed model showed a 2 to 3 percent improvement in hit rates compared to the existing model. From a practical point of view, it is expected to have a positive effect on improving consumers' purchasing satisfaction and increasing sellers' sales.

Wave Analysis and Spectrum Estimation for the Optimal Design of the Wave Energy Converter in the Hupo Coastal Sea (파력발전장치 설계를 위한후포 연안의 파랑 분석 및 스펙트럼 추정)

  • Kweon, Hyuck-Min;Cho, Hongyeon;Jeong, Weon-Mu
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.25 no.3
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    • pp.147-153
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    • 2013
  • There exist various types of the WEC (Wave Energy Converter), and among them, the point absorber is the most popularly investigated type. However, it is difficult to find examples of systematically measured data analysis for the design of the point absorber type of power buoy in the world. The study investigates the wave load acting on the point absorber type resonance power buoy wave energy extraction system proposed by Kweon et al. (2010). This study analyzes the time series spectra with respect to the three-year wave data (2002.05.01~2005.03.29) measured using the pressure type wave gage at the seaside of north breakwater of Hupo harbor located in the east coast of the Korean peninsula. From the analysis results, it could be deduced that monthly wave period and wave height variations were apparent and that monthly wave powers were unevenly distributed annually. The average wave steepness of the usual wave was 0.01, lower than that of the wind wave range of 0.02-0.04. The mode of the average wave period has the value of 5.31 sec, while mode of the wave height of the applicable period has the value of 0.29 m. The occurrence probability of the peak period is a bi-modal type, with a mode value between 4.47 sec and 6.78 sec. The design wave period can be selected from the above four values of 0.01, 5.31, 4.47, 6.78. About 95% of measured wave heights are below 1 m. Through this study, it was found that a resonance power buoy system is necessary in coastal areas with low wave energy and that the optimal design for overcoming the uneven monthly distribution of wave power is a major task in the development of a WEF (Wave Energy Farm). Finding it impossible to express the average spectrum of the usual wave in terms of the standard spectrum equation, this study proposes a new spectrum equation with three parameters, with which basic data for the prediction of the power production using wave power buoy and the fatigue analysis of the system can be given.

Analysis of the Occurrence Characteristic of Earthquake-Induced Landslide through a Media Report : Focus on International Cases Reported in Domestic Media During the 10 years (2009-2018) (언론보도를 통한 지진에 의한 산사태 발생특성 분석 : 최근 10년(2009-2018)간 국내 언론에 보도된 국외사례를 중심으로)

  • Kang, Minjeng;Kim, Kidae;Seo, Junpyo;Woo, Choongshik;Lee, Changwoo
    • Journal of the Society of Disaster Information
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    • v.16 no.3
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    • pp.440-448
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    • 2020
  • Purpose: Most of the studies in the country on earthquake-induced landslide predict the displacement of the slope. Until now, no studies have been conducted on the occurrence of landslides and damage characteristics by earthquakes. Therefore, this study was conducted to obtain basic data of landslides caused by earthquakes. Method: In order to analyze the characteristics of earthquake-causing landslides, we have collected data reported in the media over the past decade. Landslides in foreign countries were analyzed separately by cause of occurrences such as rainfall and earthquake. Landslides from abroad were analyzed according to the cause of the occurrence, and landslides caused by earthquakes were further analyzed as follows: the magnitude of an earthquake, year of occurrence, number of occurrences by continent, damage status, etc. Result: In the past 10 years, a total of 608 landslides have been reported from overseas, and the cause is the highest with 340 landslides due to rainfall. There were 70 cases of landslides caused by earthquakes, and it was analyzed as the second cause of landslides. The average magnitude for earthquakes that caused landslides was 6.5, and the minimum and maximum magnitude were 4.4 and 8.2 respectively. The earthquake-induced landslides were the most occurrence in 2011yr and 2012yr, and the continent was the most common in Asia. Also, It was analyzed that if an earthquake caused landslides, the number of casualties increased and the size of the damage increased. Conclusion: Currently, earthquakes are steadily increasing in Korea, and the possibility of strong earthquakes is also increasing. Earthquake-induced landslides are beyond human control due to natural disasters but can minimize damage through active prevention and response. It is expected that the results of this study will be used as basic data in establishing measures for earthquake landslides to reduce property and human damage in the future.

The Impact of Milk Production Level on Profit Traits of Holstein Dairy Cattle in Korea (국내 Holstein종 젖소의 생산수준이 젖소의 수익형질에 미치는 효과)

  • Do, Changhee;Park, Suhun;Cho, Kwang-Hyun;Choi, Yunho;Choi, Taejeong;Park, Byungho;Yun, Hobaek;Lee, Donghee
    • Journal of Animal Science and Technology
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    • v.55 no.5
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    • pp.343-349
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    • 2013
  • Data including 1,372,050 milk records pertaining to 438,019 cows from 1983 to 2011 collected during performance tests conducted by the National Livestock Cooperative Dairy Improvement Center were used to calculate milk income and profit of individuals and investigate the effects of production levels of early lactation (parity 1 and 2, respectively). Individuals with a moderate level of early lactation stayed longer in herds. Among parity 1, the 9,000 kg or higher group had a lower mean number of lactations than the overall mean of 3.13. The 7,000 kg or lower and 10,000 kg or higher groups had lower mean life time milking days than the overall mean of 1,076.8 days. Standard deviations of lifetime traits tended to decrease as production levels increased. For parity 2, the 11,000 kg or higher group had a lower mean number of lactation than the overall mean of 3.43. The lifetime milking days was highest in the 12,000 kg group (1,212.0 days), and generally smaller in the lower groups. Profit increased as the production level of groups increased for both parity 1 and 2. In groups with low production levels, profit of parity 1 was higher than that of parity 2, while the reverse was true in groups with high production levels. These results suggest that individuals in the low production groups had a greater likelihood to be culled due to reproductive or other problems. Furthermore, the accuracy of the prediction of lifetime profit of individuals with a milk yield of 305 days seems to be higher for parity 2 than parity 1; therefore, it is desirable to predict lifetime profit using the 305d milk yield of parity 2. In conclusion, breeding goals are based on many factors in functions for the estimation of profit; however, production levels during early lactation (parity 1 and 2) can be used as indicators of profit to extend profitability.

A Study of Insomnia and Depression of Elderly Welfare Facility Users in a City (일 도시 노인복지시설 이용자들의 불면증 및 우울증에 대한 연구)

  • Jo, Mo A;Kim, Hyun;Lee, Kang Joon
    • Korean Journal of Psychosomatic Medicine
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    • v.25 no.2
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    • pp.200-209
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    • 2017
  • Objectives : The aim of this study was to analyze the relationship between depressive symptoms and sociodemographic factors associated with geriatric depression and insomnia and to examine the effects of these factors on depression. Methods : The severities of insomnia and depression in elderly aged 60 and older lived in Gwangmyeong city were evaluated and the related sociodemographic factors were investigated. From April 20, 2016 to December 1, 2016, Gwangmyeong city Mental Health Sevices consignment by department of psychiatry of a university-affiliated general hospital conducted surveys and interviews for total 837 elderly peoples lived in Gwangmyeong city by visiting welfare center and wards located in the city. Structured interviews were conducted using Insomnia Severity Index(ISI) and Short form-Geriatric Depression Scale(S-GDS) to examine the relationship between sociodemographic factors and the severities of insomnia and depression. Results : There were significant differences in S-GDS mean scores and age(below 70 years old, 70s, 80s, above 90 years old), type of health care(health insurance, medical aid), type of residency(own, not own) and marital status(single, married, divorced or widowed).There was a significant difference in education level, especially between not educated(and/or) elementary graduates and college graduate(F=3.227, p=0.012). Also, there were significant differences in age, type of health care, type of residency, number of household on divided S-GDS score above and below 10 scores(p<0.05). Insomnia measured by ISI was not significantly associated with sociodemographic factors(p>0.05), but was significantly associated with depressive symptoms(p<0.05). These findings suggest more severe insomnia symptom indicated the higher probability of depression and elderly with depressive symptoms had more severe insomnia. Conclusions : Geriatric depression has significant relationships with age, type of health care, type of residency, marital status, education and number of households. In addition, insomnia which is main symptom of depression in elderly, has important role in predicting the severity and diagnosis of depression.

Plasma D-dimer Determination in the Diagnosis of Pulmonary Embolism (폐색전증의 진단에 있어 혈청 D-dimer 측정의 진단적 가치)

  • Lim, Chae-Man;Kim, Hong-Kyu;Choi, Kang-Hyun;Lee, Sand-Do;Koh, Youn-Suck;Kim, Woo-Sung;Jang, Jae-Suck;Kim, Dong-Soon;Kim, Won-Dong
    • Tuberculosis and Respiratory Diseases
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    • v.43 no.1
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    • pp.69-74
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    • 1996
  • Background: The diagnosis of pulmonary embolism (PE) based on clinical findings is often elusive and therefore requires confirmative diagnostic method. Pulmonary angiography, though the gold standard for the diagnosis of pulmonary embolism, is an invasive method and requires trained personnel and special equipment. Lung V/Q scan, on the other hand, is a noninvasive method but the diagnostic specificity and sensitivity arc not satisfactory in case that the results are either intermediate or low probability scan. Plasma D-dimer is generated when a thrombus is fibrinolysed by plasmin and is known to be increased in various thrombotic disorders. The aim of this study was to investigate the value of the determination of plasma D-dimer level in the diagnosis of pulmonary embolism. Methods: Pulmonary angiography was performed in 17 patients who were clinically suspected to have pulmonary embolism. 9 patients(PE, $56{\pm}13.4$ yrs, M:F=8:1) were diagnosed to have pulmonary embolism by pulmonary angiography. The control group were the 8 patients with negative pulmonary angiography and 13 orthopedic patients with no evidence of pulmonary embolism on scintigraphic and impedance plethysmographic studies(n=21) (non-PE, $54.5{\pm}11.1$ yrs, M:F=11:10). Plasma D-dimer was measured by latex agglutination method in study subjects and the results were analyzed according to the presence or absence of pulmonary embolism. Results: 1) The increased level of plasma D-dimer was more frequently observed in the patients with pulmonary embolism than in the controls(>0.5 mg/L, 8 in PE, 10 in non-PE; <0.5 mg/L, 1 in PE, 11 in non-PE, p=0.049). 2) The diagnostic value of plasma D-dimer level higher than 0.5 mg/L were as follows: sensitivity 88.9%(8/9), specificity 52.4%(11/21), positive predictive value 44.4%(8/18), and negative predictive value 91.7%(11/12). Conclusion: Plasma D-dimer determination showed high sensitivity and negative predictive value in the diagnosis of pulmonary embolism and is therefore thought to be useful in excluding the possibility of pulmonary embolism.

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