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A Folksonomy Ranking Framework: A Semantic Graph-based Approach (폭소노미 사이트를 위한 랭킹 프레임워크 설계: 시맨틱 그래프기반 접근)

  • Park, Hyun-Jung;Rho, Sang-Kyu
    • Asia pacific journal of information systems
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    • v.21 no.2
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    • pp.89-116
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    • 2011
  • In collaborative tagging systems such as Delicious.com and Flickr.com, users assign keywords or tags to their uploaded resources, such as bookmarks and pictures, for their future use or sharing purposes. The collection of resources and tags generated by a user is called a personomy, and the collection of all personomies constitutes the folksonomy. The most significant need of the folksonomy users Is to efficiently find useful resources or experts on specific topics. An excellent ranking algorithm would assign higher ranking to more useful resources or experts. What resources are considered useful In a folksonomic system? Does a standard superior to frequency or freshness exist? The resource recommended by more users with mere expertise should be worthy of attention. This ranking paradigm can be implemented through a graph-based ranking algorithm. Two well-known representatives of such a paradigm are Page Rank by Google and HITS(Hypertext Induced Topic Selection) by Kleinberg. Both Page Rank and HITS assign a higher evaluation score to pages linked to more higher-scored pages. HITS differs from PageRank in that it utilizes two kinds of scores: authority and hub scores. The ranking objects of these pages are limited to Web pages, whereas the ranking objects of a folksonomic system are somewhat heterogeneous(i.e., users, resources, and tags). Therefore, uniform application of the voting notion of PageRank and HITS based on the links to a folksonomy would be unreasonable, In a folksonomic system, each link corresponding to a property can have an opposite direction, depending on whether the property is an active or a passive voice. The current research stems from the Idea that a graph-based ranking algorithm could be applied to the folksonomic system using the concept of mutual Interactions between entitles, rather than the voting notion of PageRank or HITS. The concept of mutual interactions, proposed for ranking the Semantic Web resources, enables the calculation of importance scores of various resources unaffected by link directions. The weights of a property representing the mutual interaction between classes are assigned depending on the relative significance of the property to the resource importance of each class. This class-oriented approach is based on the fact that, in the Semantic Web, there are many heterogeneous classes; thus, applying a different appraisal standard for each class is more reasonable. This is similar to the evaluation method of humans, where different items are assigned specific weights, which are then summed up to determine the weighted average. We can check for missing properties more easily with this approach than with other predicate-oriented approaches. A user of a tagging system usually assigns more than one tags to the same resource, and there can be more than one tags with the same subjectivity and objectivity. In the case that many users assign similar tags to the same resource, grading the users differently depending on the assignment order becomes necessary. This idea comes from the studies in psychology wherein expertise involves the ability to select the most relevant information for achieving a goal. An expert should be someone who not only has a large collection of documents annotated with a particular tag, but also tends to add documents of high quality to his/her collections. Such documents are identified by the number, as well as the expertise, of users who have the same documents in their collections. In other words, there is a relationship of mutual reinforcement between the expertise of a user and the quality of a document. In addition, there is a need to rank entities related more closely to a certain entity. Considering the property of social media that ensures the popularity of a topic is temporary, recent data should have more weight than old data. We propose a comprehensive folksonomy ranking framework in which all these considerations are dealt with and that can be easily customized to each folksonomy site for ranking purposes. To examine the validity of our ranking algorithm and show the mechanism of adjusting property, time, and expertise weights, we first use a dataset designed for analyzing the effect of each ranking factor independently. We then show the ranking results of a real folksonomy site, with the ranking factors combined. Because the ground truth of a given dataset is not known when it comes to ranking, we inject simulated data whose ranking results can be predicted into the real dataset and compare the ranking results of our algorithm with that of a previous HITS-based algorithm. Our semantic ranking algorithm based on the concept of mutual interaction seems to be preferable to the HITS-based algorithm as a flexible folksonomy ranking framework. Some concrete points of difference are as follows. First, with the time concept applied to the property weights, our algorithm shows superior performance in lowering the scores of older data and raising the scores of newer data. Second, applying the time concept to the expertise weights, as well as to the property weights, our algorithm controls the conflicting influence of expertise weights and enhances overall consistency of time-valued ranking. The expertise weights of the previous study can act as an obstacle to the time-valued ranking because the number of followers increases as time goes on. Third, many new properties and classes can be included in our framework. The previous HITS-based algorithm, based on the voting notion, loses ground in the situation where the domain consists of more than two classes, or where other important properties, such as "sent through twitter" or "registered as a friend," are added to the domain. Forth, there is a big difference in the calculation time and memory use between the two kinds of algorithms. While the matrix multiplication of two matrices, has to be executed twice for the previous HITS-based algorithm, this is unnecessary with our algorithm. In our ranking framework, various folksonomy ranking policies can be expressed with the ranking factors combined and our approach can work, even if the folksonomy site is not implemented with Semantic Web languages. Above all, the time weight proposed in this paper will be applicable to various domains, including social media, where time value is considered important.

The Effects of Cattle Slurry Application and Mixed Sowing with legumes on Productivity and Feed Values of Barley and Rye (액상우분뇨와 콩과식물 혼파재배가 보리, 호밀의 생산성과 사료가치에 미치는 영향)

  • Jo, IK-Hwan
    • Korean Journal of Organic Agriculture
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    • v.17 no.3
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    • pp.371-380
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    • 2009
  • This study was conducted to assess effects of supplying different types of nitrogen sources as fertilizers on productivity and feed values of barley and rye as winter forage crops, and ultimately done to get good quality of organic forages with higher fertilization of soil. For barley, N+P+K plots were significantly (P<0.05) higher in annual dry matter (DM) and total digestible nutrients (TDN) yields than other plots. However, cattle manure plots had significantly (P<0.05) higher annual DM and TDN than P+K and non-fertilizer plots. Plots of 50%-cattle manure and mixed sowing with hairy vetch or forage pea were higher than only 50%-cattle manure plot, particularly, these were significantly higher than non-fertilizer, and their crude protein (CP) yields were much higher than other plots. Crude protein contents were significantly higher in N+P+K and 50%-cattle manure slurry plots than non-fertilizer and P+K plots, and plots of mixed sowing with hairy vetch or forage pea in application of 50%-cattle manure had higher CP content than other plots. ADF content was lowest in 50%-cattle manure+forage pea plots, but highest in 100%-cattle manure plots. NDF content was lowest in legumes-mixed sowing, but highest in 100%-cattle manure plots. TDN content was the highest in forage pea plots, and plots of 50%-cattle manure and legumes-mixed sowing had high RFV, but cattle manure plots rich in ADF and NDF content had the lowest TDN and RFV. For rye, plots of 50%-cattle manure+hairy vetch mixed sowing, and N+P+K application had significantly higher annual DM, CP and TDN than other plots except for cattle manure. DM productive efficiency to nitrogen fertilization was markedly higher for cattle manure plots than for chemical fertilizer. This tendency was more conspicuous in plots of 50% cattle manure+legumes-mixed sowing. CP content was higher for N+P+K plot than for all plots, and plots of 50%-cattle manure + legumes-mixed sowing were significantly higher than other plots. On the contrary, forage pea-mixed sowing plot had the lowest ADF and NDF, but TDN and RFV were significantly (P<0.05) higher than other plots. Grass crop cultivation together with legumes by applying livestock manure to soil may lead to higher palatability of livestock, and better quality of forage. Furthermore, cattle manure application increased production yield per ha and CP contents. Thus, when applying forage crops produced by cattle manure application and mixed sowing to organic livestock production, it was conceived that forages produced might become a substitute for foreign organic grain as protein sources.

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Surgical Treatment of Anomalous Origin of Coronary Artery from the Pulmonary Artery: Postoperative Changes of Ventricular Dimensions and Mitral Regurgitation (관상동맥-폐동맥 이상기시증(Anomalous Origin of Coronary Artery from Pulmonary Artery)의 수술적 치료: 중기 성적과 좌심실 및 승모판 기능의 변화 양상에 대한 연구)

  • Kang, Chang-Hyun;Kim, Woong-Han;Seo, Hong-Joo;Kim, Jae-Hyun;Lee, Cheul;Chang, Yoon-Hee;Hwang, Seong-Wook;Back, Man-Jong;Oh, Sam-Se;Na, Chan-Young;Han, Jae-Jin;Lee, Young-Tak;Kim, Chong-Whan
    • Journal of Chest Surgery
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    • v.37 no.1
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    • pp.19-26
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    • 2004
  • Background: The aims of this study are to verify the result of the surgical treatment of ALCAPA and to identify the postoperative changes of left ventricular dimensions and mitral regurgitation (MR), Material and Method: Fifteen patients operated on since 1985 were included in the study. The patients operated on before 1998 (n=9) showed heterogeneous properties with various surgical strategies and cardiopulmonary bypass techniques. However, six patients were operated on with the established surgical strategy since 1998; 1) Dual perfusion and dual cardioplegic solution delivery through ascending aorta and main pulmonary artery, 2) Coronary transfer by rolled-conduit made of pulmonary artery wall flap, and 3) Additional mitral valvular procedure was not peformed. Result: Median age of the study group was 6 months (1 month to 34 years). The operative methods were left subclavian artery to left coronary artery anastomosis in 1, simple ligation in 2, Takeuchi operation in 2, and coronary reimplantation in 10 patients. The mean follow up period was 5.5<5.8 years (2 months 14 years), There were one early death (6.7%) and one late death. Overall 5-year survival rate was 85.6$\pm$9.6%. The Z-value of left ventricular end-diastolic and end-systolic dimensions were 6.4$\pm$3.0 and 5.1 $\pm$3.6 preoperatively, and decreased to 1.7$\pm$ 1.9 and 0.8$\pm$ 1.6 in 3 months (p<0.05). Significant preoperative MR was identified in 6 patients (40%) and all the patients showed immediate improvement of MR within f month postoperatively. There were 3 cases of reoperation due to coronary anastomosis site stenosis and recurrence of MR. However, there was no mortality nor late reoperation in the patients operated on after 1998. Conclusion: The surgical treatment of ALCAPA showed favorable survival and early recovery of ventricular dimensions and mitral valvular function. Although long-term reintervention was required in some cases of earlier period, all the cases after 1998 showed excellent surgical outcome without long-term problem.

The Correction Factor of Sensitivity in Gamma Camera - Based on Whole Body Bone Scan Image - (감마카메라의 Sensitivity 보정 Factor에 관한 연구 - 전신 뼈 영상을 중심으로 -)

  • Jung, Eun-Mi;Jung, Woo-Young;Ryu, Jae-Kwang;Kim, Dong-Seok
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.3
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    • pp.208-213
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    • 2008
  • Purpose: Generally a whole body bone scan has been known as one of the most frequently executed exams in the nuclear medicine fields. Asan medical center, usually use various gamma camera systems - manufactured by PHILIPS (PRECEDENCE, BRIGHTVIEW), SIEMENS (ECAM, ECAM signature, ECAM plus, SYMBIA T2), GE (INFINIA) - to execute whole body scan. But, as we know, each camera's sensitivity is not same so it is hard to consistent diagnosis of patients. So our purpose is when we execute whole body bone scans, we exclude uncontrollable factors and try to correct controllable factors such as inherent sensitivity of gamma camera. In this study, we're going to measure each gamma camera's sensitivity and study about reasonable correction factors of whole body bone scan to follow up patient's condition using different gamma cameras. Materials and Methods: We used the $^{99m}Tc$ flood phantom, it recommend by IAEA recommendation based on general counts rate of a whole body scan and measured counts rates by the use of various gamma cameras - PRECEDENCE, BRIGHTVIEW, ECAM, ECAM signature, ECAM plus, IFINIA - in Asan medical center nuclear medicine department. For measuring sensitivity, all gamma camera equipped LEHR collimator (Low Energy High Resolution multi parallel Collimator) and the $^{99m}Tc$ gamma spectrum was adjusted around 15% window level, the photo peak was set to 140-kev and acquirded for 60 sec and 120 sec in all gamma cameras. In order to verify whether can apply calculated correction factors to whole body bone scan or not, we actually conducted the whole body bone scan to 27 patients and we compared it analyzed that results. Results: After experimenting using $^{99m}Tc$ flood phantom, sensitivity of ECAM plus was highest and other sensitivity order of all gamma camera is ECAM signature, SYMBIA T2, ECAM, BRIGHTVIEW, IFINIA, PRECEDENCE. And yield sensitivity correction factor show each gamma camera's relative sensitivity ratio by yielded based on ECAM's sensitivity. (ECAM plus 1.07, ECAM signature 1.05, SYMBIA T2 1.03, ECAM 1.00, BRIGHTVIEW 0.90, INFINIA 0.83, PRECEDENCE 0.72) When analyzing the correction factor yielded by $^{99m}Tc$ experiment and another correction factor yielded by whole body bone scan, it shows statistically insignificant value (p<0.05) in whole body bone scan diagnosis. Conclusion: In diagnosing the bone metastasis of patients undergoing cancer, whole body bone scan has been conducted as follow up tests due to its good points (high sensitivity, non invasive, easily conducted). But as a follow up study, it's hard to perform whole body bone scan continuously using same gamma camera. If we use same gamma camera to patients, we have to consider effectiveness of equipment's change by time elapsed. So we expect that applying sensitivity correction factor to patients who tested whole body bone scan regularly will add consistence in diagnosis of patients.

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Summer-Time Behaviour and Flux of Suspended Sediments at the Entrance to Semi-Closed Hampyung Bay, Southwestern Coast of Korea (만 입구에서 부유퇴적물 거동과 플럭스: 한반도 서해 남부 함평만의 여름철 특성)

  • Lee, Hee-Jun;Park, Eun-Sun;Lee, Yeon-Gyu;Jeong, Kap-Sik;Chu, Yong-Shik
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.5 no.2
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    • pp.105-118
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    • 2000
  • Anchored measurements (12.5 hr) of suspended sediment concentration and other hydrodynamic parameters were carried out at two stations located at the entrance to Hampyung Bay in summer (August 1999). Tidal variations in water temperature and salinity were in the range of 26.0-27.9$^{\circ}C$ and 30.9-31.5, respectively, indicating exchange offshore and offshore water mass. Active tidal mixing processes at the entrance appear to destroy the otherwise vertical stratification in temperature and salinity in spite of strong solar heating in summer. On the contrary, suspended sediment concentrations show a marked stratification with increasing concentrations toward bottom layer. Clastic particles in suspended sediments consist mostly of very fine to fine silt (4-16 ${\mu}$m) with a poorly-sorted value of 14.7-25.9 ${\mu}$m. However, at slack time with less turbulent energy, flocs larger than 40 ${\mu}$m are formed by cohesion and inter-collision of particles, resulting in a higher settling velocity. Strong ebb-dominated and weak flood dominated tidal currents, in the southwestern and the northeastern part, respectively, result in a seaward residual flow of -10${\sim}$-20 cm $s^{-1}$ at station H1 and a bayward residual flow less than 5.0 cm $s^{-1}$ at station H2. However, mean concentration of suspended sediments at station H1 is higher at flood (95.0-144.1 mg $1^{-1}$) than in ebb (75.8-120.9 mg $1^{-1}$). On the contrary, at the station H2, the trend is reversed with higher concentration at the ebb (84.7-158.4 mg $1^{-1}$) than that at the flood (53.0-107.9 mg $1^{-1}$). As a result, seaward net suspended sediment fluxes ($f_{s}$) are calculated to be -1.7 ${\sim}$-$15.610^{3}$ kg $m^{-2}$ $s^{-1}$ through the whole water column. However, the stations H1 and H2 show definitely different values of the flux with higher ones in the former than in the latter. Alternatively, depth-integrated net suspended sediment loads ($\c{Q}_{s}$) for one tidal cycle are also toward the offshore with ranges of 0.37${\times}$$10^{3}$ kg $m^{-1}$ and 0.21${\times}$$10^{3}$ kg $m^{-1}$, at station H1 and H2, respectively. This seaward transport of suspended sediment in summer suggests that summer-time erosion in the Hampyung muddy tidal flats is a rather exceptional phenomenon compared to the general deposition reported for many other tidal flats on the west coast of Korea.

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Fermentation Characteristics of Juice Pomace Feed by Horse Feces Microbes (말분변 미생물을 이용한 주스박 사료의 발효 특성)

  • Hwang, Won-Uk;Kim, Gyeom-Heon;Niu, Kai-Min;Lim, Joung-Ho;Woo, Jae-Hoon;Chae, Hyun-Seok;Park, Nam-Geon;Kim, Soo-Ki
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.37 no.4
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    • pp.290-300
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    • 2017
  • In vitro fermentation was conducted to figure out alternative fiber sources for horse feed. For the development of value-added products as a horse feed resource, the pomaces from apple, carrot, grape, and citrus were fermented under solid-state conditions in the presence of 60% soybean meal with 40% of each fruit pomace at 60% of moisture content. Lactobacillus plantarum SK3873, Lactobacillus plantarum SK3893, Weissella cibaria SK3880, and Bacillus subtilis SK3889 were isolated from the fermented fruit pomace by inoculation of horse feces. For the growth of Bacillus subtilis, Saccharomyces cerevisiae, and Lactobacillus plantarum, they were inoculated in 3-step order at 0, 12, and 24 h, respectively. The fruit pomace was fermented for 48 h at $35^{\circ}C$. The pH of the apple, carrot, grape, citrus and all mixed pomaces decreased from 5.45~6.25 to 4.40~4.77. Microbial growth was maintained at $10^8{\sim}10^9cfu/g$. After 12 and 24 h incubation, dry matter of carrot pomace were highest at 54.84 and 56.66%, respectively (P<0.05) and that of grape pomace was lower than others during fermentation (P<0.05). Dry matter was generally reduced by about 20%. NDF decreased gradually or maintained after 24 h, indicating the fiber degradation. Ash content tended to decrease during fermentation. After 48 hours fermentation, Bacillus, yeast and Lactobacillus showed an excellent growth by using juice by-products. These results suggest that fermented juice pomace has a potential as horse feedstuff with probiotics to maintain beneficial microflora in horse gut.

Agronomic Characteristics and Productivity of Winter Forage Crop in Sihwa Reclaimed Field (시화 간척지에서 월동 사료작물의 초종 및 품종에 따른 생육특성 및 생산성)

  • Kim, Jong Geun;Wei, Sheng Nan;Li, Yan Fen;Kim, Hak Jin;Kim, Meing Joong;Cheong, Eun Chan
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.40 no.1
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    • pp.19-28
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    • 2020
  • This study was conducted to compare the agronomic characteristics and productivity according to the species and varieties of winter forage crops in reclaimed land. Winter forage crops used in this study were developed in National Institute of Crop Science, RDA. Oats ('Samhan', 'Jopung', 'Taehan', 'Dakyung' and 'Hi-early'), forage barley ('Yeongyang', 'Yuyeon', 'Yujin', 'Dacheng' and 'Yeonho'), rye ('Gogu', 'Jogreen' and 'Daegokgreen') and triticale ('Shinyoung', 'Saeyoung', 'Choyoung', 'Sinseong', 'Minpung' and 'Gwangyoung') were planted in the reclaimed land of Sihwa district in Hwaseong, Gyeonggi-do in the autumn of 2018 and cultivated using each standard cultivation method, and harvested in May 2019(oat and rye: 8 May, barley and triticale: 20 May.) The emergency rate was the lowest in rye (84.4%), and forage barley, oat and triticale were in similar levels (92.8 to 98.8%). Triticale was the lowest (416 tiller/㎡) and oat was the highest (603 tiller/㎡) in tiller number. Rye was the earliest in the heading date (April 21), triticale was April 26, and oat and forage barley were in early May (May 2 and May 5). The plant height was the highest in rye (95.6 cm), and triticale and forage barley was similar (76.3 and 68.3cm) and oat was the lowest (54.2 cm). Dry matter(DM) content of rye was the highest in the average of 46.04% and the others were similar at 35.09~37.54%. Productivity was different among species and varieties, with the highest dry matter yield of forage barley (4,344 kg/ha), oat was similar to barley, and rye and triticale were lowest. 'Dakyoung' and 'Hi-early' were higher in DM yield (4,283 and 5,490 kg/ha), and forage barley were higher in 'Yeonho', 'Yujin' and 'Dacheng' varieties (4,888, 5,433 and 5,582 kg/ha). Crude protein content of oat (6.58%) tended to be the highest, and TDN(total digectible nutrient) content (63.61%) was higher than other varieties. In the RFV(relative feed value), oats averaged 119, while the other three species averaged 92~105. The weight of 1,000 grain was the highest in triticale (43.03 g) and the lowest in rye (31.61 g). In the evaluation of germination rate according to the salt concentration (salinity), the germination rate was maintained at about 80% from 0.2 to 0.4% salinity. The correlation coefficient between germination and salt concentration was high in oat and barley (-0.91 and -0.92) and lowest in rye (-0.66). In conclusion, forage barley and oats showed good productivity in reclaimed land. Adaptability is also different among varieties of forage crops. When growing forage crops in reclaimed land, the selection of highly adaptable species and varieties was recommended.

Effects of Lime and NPK Application Rates on the Soil Characteristics after a 10-year Experiment in Oversown Hilly Pasture of Mixed Grass-Clover Sward I. Changes in the pH, contents of T-N, organic matter and available $P_{2}O_{5}$, coefficient of $P_{2}O_{5}$ absorption, and lime requirement by the soil depth (겉뿌림 산지초지에서 석회 및 3요소 시용수준이 10연후 토양특성에 미치는 영향 I. 토심별 pH, T-N, 유기물 및 유효인산 함량, 인기흡수계수와 석회소요량)

  • Jeong, Yeon-Gyu;Lee, Hyeok-Ho
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.13 no.1
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    • pp.49-57
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    • 1993
  • The main experiment related to this report was undertaken to assess the effects of two rates of $Ca(OH)_2$ (0, 250 kg/10a only at establishment) and five rates of N-$P_{2}O_{5}$-$K_2O$ (0-0-0, 0-10-10, 6-15-15, 12-20-20, 24-25-20 kg/10a/year) on the pasture establishment, on forage yield and quality, vegetation etc. After this 10-year main experiment, this pasture had been used to assess the effects of the above treatments on the soil characteristics in oversown hilly pasture of a grass-clover sward. This 1st part is concerned with the soil properties of pH-value. OM, T-N, avail. $P_{2}O_{5}$ and $P_{2}O_{5}$ absorption coefficient, and lime requirement by the soil depth. 1. The pH of the topsoil(0~l5 cm) was lowered from pH 5.12 of before the experiment to 4.90 of when $Ca(OH)_2$ was applied and to 4.68 of when $Ca(OH)_2$ was not applied. The pH decrease was more evident with the increase of NPK application rate and in the upper part of the top soil(0.0~7.5 cm). The additional application of lime was necessary in all the experiment blocks due to the strong acidity of the soil, and the amounts of lime requirement were increased with increased application rates of NPK and soil depth. 2. The contents of organic matter and T-N were increased in all the blocks by the establishment of the hilly pasture, and were higher in $Ca(OH)_2$ applied blocks than non-applied blocks. The contents were inversely correlated with the soil depth. No correlation was observed between the contents and the application rates of NPK. 3. The content of available $P_{2}O_{5}$-$K_2O$, was increased with the increased application of P, especially in the upper part of top soil. The content in the upper part(0.0~7.5 cm) was about twice of that in the lower part(7.5~15.0 cm). Since the contents of available $P_{2}O_{5}$$P_{2}O_{5}$/10a/year were applied, respectively), it is necessary to decrease the application rate of $P_{2}O_{5}$, gradually. The $P_{2}O_{5}$ absorption coefficient in topsoil (0.0~15.0 cm) was more or less higher when no lime and less $P_{2}O_{5}$, was applied. No correlation was observed in subsoil. 4. Further studies on the methods, rates, time of additional application of lime, and on the methods of decreased apllication of $P_{2}O_{5}$ should be performed for better management of oversown hilly pasture.

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Performance analysis of Frequent Itemset Mining Technique based on Transaction Weight Constraints (트랜잭션 가중치 기반의 빈발 아이템셋 마이닝 기법의 성능분석)

  • Yun, Unil;Pyun, Gwangbum
    • Journal of Internet Computing and Services
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    • v.16 no.1
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    • pp.67-74
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    • 2015
  • In recent years, frequent itemset mining for considering the importance of each item has been intensively studied as one of important issues in the data mining field. According to strategies utilizing the item importance, itemset mining approaches for discovering itemsets based on the item importance are classified as follows: weighted frequent itemset mining, frequent itemset mining using transactional weights, and utility itemset mining. In this paper, we perform empirical analysis with respect to frequent itemset mining algorithms based on transactional weights. The mining algorithms compute transactional weights by utilizing the weight for each item in large databases. In addition, these algorithms discover weighted frequent itemsets on the basis of the item frequency and weight of each transaction. Consequently, we can see the importance of a certain transaction through the database analysis because the weight for the transaction has higher value if it contains many items with high values. We not only analyze the advantages and disadvantages but also compare the performance of the most famous algorithms in the frequent itemset mining field based on the transactional weights. As a representative of the frequent itemset mining using transactional weights, WIS introduces the concept and strategies of transactional weights. In addition, there are various other state-of-the-art algorithms, WIT-FWIs, WIT-FWIs-MODIFY, and WIT-FWIs-DIFF, for extracting itemsets with the weight information. To efficiently conduct processes for mining weighted frequent itemsets, three algorithms use the special Lattice-like data structure, called WIT-tree. The algorithms do not need to an additional database scanning operation after the construction of WIT-tree is finished since each node of WIT-tree has item information such as item and transaction IDs. In particular, the traditional algorithms conduct a number of database scanning operations to mine weighted itemsets, whereas the algorithms based on WIT-tree solve the overhead problem that can occur in the mining processes by reading databases only one time. Additionally, the algorithms use the technique for generating each new itemset of length N+1 on the basis of two different itemsets of length N. To discover new weighted itemsets, WIT-FWIs performs the itemset combination processes by using the information of transactions that contain all the itemsets. WIT-FWIs-MODIFY has a unique feature decreasing operations for calculating the frequency of the new itemset. WIT-FWIs-DIFF utilizes a technique using the difference of two itemsets. To compare and analyze the performance of the algorithms in various environments, we use real datasets of two types (i.e., dense and sparse) in terms of the runtime and maximum memory usage. Moreover, a scalability test is conducted to evaluate the stability for each algorithm when the size of a database is changed. As a result, WIT-FWIs and WIT-FWIs-MODIFY show the best performance in the dense dataset, and in sparse dataset, WIT-FWI-DIFF has mining efficiency better than the other algorithms. Compared to the algorithms using WIT-tree, WIS based on the Apriori technique has the worst efficiency because it requires a large number of computations more than the others on average.

Medical Information Dynamic Access System in Smart Mobile Environments (스마트 모바일 환경에서 의료정보 동적접근 시스템)

  • Jeong, Chang Won;Kim, Woo Hong;Yoon, Kwon Ha;Joo, Su Chong
    • Journal of Internet Computing and Services
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    • v.16 no.1
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    • pp.47-55
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    • 2015
  • Recently, the environment of a hospital information system is a trend to combine various SMART technologies. Accordingly, various smart devices, such as a smart phone, Tablet PC is utilized in the medical information system. Also, these environments consist of various applications executing on heterogeneous sensors, devices, systems and networks. In these hospital information system environment, applying a security service by traditional access control method cause a problems. Most of the existing security system uses the access control list structure. It is only permitted access defined by an access control matrix such as client name, service object method name. The major problem with the static approach cannot quickly adapt to changed situations. Hence, we needs to new security mechanisms which provides more flexible and can be easily adapted to various environments with very different security requirements. In addition, for addressing the changing of service medical treatment of the patient, the researching is needed. In this paper, we suggest a dynamic approach to medical information systems in smart mobile environments. We focus on how to access medical information systems according to dynamic access control methods based on the existence of the hospital's information system environments. The physical environments consist of a mobile x-ray imaging devices, dedicated mobile/general smart devices, PACS, EMR server and authorization server. The software environment was developed based on the .Net Framework for synchronization and monitoring services based on mobile X-ray imaging equipment Windows7 OS. And dedicated a smart device application, we implemented a dynamic access services through JSP and Java SDK is based on the Android OS. PACS and mobile X-ray image devices in hospital, medical information between the dedicated smart devices are based on the DICOM medical image standard information. In addition, EMR information is based on H7. In order to providing dynamic access control service, we classify the context of the patients according to conditions of bio-information such as oxygen saturation, heart rate, BP and body temperature etc. It shows event trace diagrams which divided into two parts like general situation, emergency situation. And, we designed the dynamic approach of the medical care information by authentication method. The authentication Information are contained ID/PWD, the roles, position and working hours, emergency certification codes for emergency patients. General situations of dynamic access control method may have access to medical information by the value of the authentication information. In the case of an emergency, was to have access to medical information by an emergency code, without the authentication information. And, we constructed the medical information integration database scheme that is consist medical information, patient, medical staff and medical image information according to medical information standards.y Finally, we show the usefulness of the dynamic access application service based on the smart devices for execution results of the proposed system according to patient contexts such as general and emergency situation. Especially, the proposed systems are providing effective medical information services with smart devices in emergency situation by dynamic access control methods. As results, we expect the proposed systems to be useful for u-hospital information systems and services.