• Steel and Composite Structures
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• v.51 no.4
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• pp.351-361
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• 2024

Accurate measurement of K_IC values for gas pipeline steels is important for assessing pipe safety using failure assessment diagrams. As direct measurement of K_IC was impossible for the API X70 pipeline steel, multi-specimen fracture tests were conducted to measure J_IC using three-point bend geometry. The J values were calculated from load-displacement (F-δ) plots, and the associated crack extensions were measured from the fracture surface of test specimens. Valid data points were found for the constructed J-Δa plot resulting in J_IC=356kN/m. More data points were added analytically to the J-Δa plot to increase the number of data points without performing additional experiments for different J-Δa zones where test data was unavailable. Consequently, displacement (δ) and crack-growth (Δa) from multi-specimen tests (with small displacements) were used simultaneously, resulting in the variation of Δa-δ (crack growth law) and δ-Δa obtained for this steel. For new Δa values, corresponding δ values were first calculated from δ-Δa. Then, corresponding J values for the obtained δ values were calculated from the area under the F-δ record of a full-fractured specimen (with large displacement). Given Δa and J values for new data points, the developed J-Δa plot with extra data points yielded a satisfactory estimation of J_IC=345kN/m with only a -3.1% error. This is promising and showed that the developed technique could ease the estimation of J_IC significantly and reduce the time and cost of expensive extra fracture toughness tests.

• Journal of Korean Academy of Nursing
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• v.54 no.3
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• pp.311-328
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• 2024

Purpose: In this study a systematic review and meta-analysis investigated the impact of non-pharmacological interventions on major adverse cardiac events (MACE) in patients with coronary artery disease who underwent percutaneous coronary intervention (PCI). Methods: A literature search was performed using PubMed, Cochrane Library, EMBASE, and Cumulative Index to Nursing & Allied Health Literature databases up to November 2023. The risk of bias was assessed using the Cochrane Risk of Bias 2.0 tool. Effect sizes and 95% confidence intervals were calculated using R software (version 4.3.2). Results: Eighteen randomized studies, involving 2,898 participants, were included. Of these, 16 studies with 2,697 participants provided quantitative data. Non-pharmacological interventions (education, exercise, and comprehensive) significantly reduced the risk of angina, heart failure, myocardial infarction, restenosis, cardiovascular-related readmission, and cardiovascular-related death. The subgroup meta-analysis showed that combined interventions were effective in reducing the occurrence of myocardial infarction (MI), and individual and group-based interventions had significant effects on reducing the occurrence of MACE. In interventions lasting seven months or longer, occurrence of decreased by 0.16 times, and mortality related to cardiovascular disease decreased by 0.44 times, showing that interventions lasting seven months or more were more effective in reducing MI and cardiovascular disease-related mortality. Conclusion: Further investigations are required to assess the cost-effectiveness of these interventions in patients undergoing PCI and validate their short- and long-term effects. This systematic review underscores the potential of non-pharmacological interventions in decreasing the incidence of MACE and highlights the importance of continued research in this area (PROSPERO registration number: CRD42023462690).

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.1 no.1
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• pp.37-44
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• 1998

Purpose: This study aimed at evaluating the therapeutic outcome, cost effectiveness and recurrence rate in children with H. pylori infection after the treatment using various medications. Methods: Seventy five children (mean age $11.4{\pm}2.5$ years) were given an endoscopy with biopsy and H. pylori status assessed by CLO test and histologic examination (Warthin Starry stain). Children were given one of following medications such as DA ($Denol^{(R)}$ and amoxycillin), OA (omeprazole and amoxycillin), DC ($Denol^{(R)}$ and clarithromycin) as primary treatment. And one of following medications such as DAM ($Denol^{(R)}$, amoxycillin and metronidazole), DC, OA, OC (omeprazole and clarithromycin) were used in children who failed the eradication of H. pylori. Results: The endoscopic diagnoses were: nodular gastritis (46 cases), gastric ulcer (9), duodenal ulcer (6), superficial gastritis (6), and normal (8). H. pylori eradication rate was 91% (63 of 69 children) on 4 weeks course of DA, 50% (1 of 2 cases who had treatment failure on DA) on DAM, and 75% (3 of 4 cases who treated on DC primarily) and 50% (1 of 2 cases who had treatment failure on DA) on DC, and 100% on OA (all of 2) and on OC (all of 1 who failed on DA). In 3 of 7 children in whom H. pylori had not been eradicated by primary medications (DA 6 and DC 1 case), H. pylori was re-eradicated by secondary medications (DA 1, DAM 1 and DC 1 case). But in remaining 4 cases, H. pylori infection persisted. Reinfection of H. pylori was found in 4 of 75 children between 3 months and 3 years after completion of the treatment of DA, yielding recurrence rate of 5.3%. In 2 of 4 cases who had relapsed, H. pylori was re-eradicated by secondary medications (OC 1 and DA 1 case). But in remaining 2 cases, H. pylori infection persisted. Conclusion: These results suggest that dual therapy with $Denol^{(R)}$ and amoxycillin is the effective medications in treating H. pylori infection in children. Concerning the cost effectiveness, it can be recommended as first line treatment of choice as well.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.619-624
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• 1996

An experiment was carried out to find out the effects of water foxtail on weed control and rice yield as well as on the reduction of nitrogen application in no tillage transplanted paddy field. Paddy field was dominated by water foxtail whose soil covering degree was adjusted from 8 to 6 by treatment of paraquat (70 l /10a of solution diluted by 1, 000 times). Thirty five-day old seedling was mechanically transplanted and reduced nitrogen, 80% of conventional application was applied at the paddy field. The higher failure in seedling stand was observed at higher degree of soil covering by water foxtail. The failure of seedling stand with covering degree of 8(no paraquat) was 37.4%, while that of covering degree of 6(paraquat-treated) was 12.3%. However, the seedling stand failure was completely recovered at covering degree of six at two weeks after transplanting. The mechanical transplanting made water foxtail in the paddy field fall on the ground whose panicle part was recovered from falling sometimes after transplanting and whole plant died with slow scenesence untill the late of June. But the water foxtail affected by paraquat produced the new panicle from uppernode of stem with dead leaves at early of June and it become die slowly untill the early of July. Though several rice field weeds were observed in the order of Echinochloa crusgallis, Cyperus serotinus, Lemma paucicostata during the active tillering stage of rice, the value of weed control due to the dominance of water foxtail was 77~78%. The death and subsequent decay of water foxtail during the active tillering stage of rice induced the soil reduction which again defect the growth of rice root. The more vigerous rice growth was observed in the plot dominated with water foxtails, than control plot. The yields of rice in the water foxtail (degree 6) plot was 629kg per l0a as brown rice, the same as that of control plot. In conclusion, the no-tillage transplanting with control of covering degree of water foxtail (to degree 6) was effective in reduction of input cost such as herbicide and nitrogen fertilizer, as well as weed control without reduction of rice yield.

• Journal of Animal Environmental Science
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• v.17 no.1
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• pp.39-48
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• 2011

The present survey was conducted to provide basic information on automatic milking system (AMS) in relation to purchase motive, milk yield and quality, customer satisfaction, difficulties of operation and customer suggestions, etc. Purchase motives of AMS were insufficient labor (44%), planning of dairy experience farm (25%), better performance of high yield cows (19%) and others (6%), respectively. Average cow performance after using AMS was 30.9l/d for milk yield, 3.9% for milk fat, 9,100/ml for bacterial counts. Sixty-eight percentage of respondents were very positive in response to AMS use for their successors but 18% were negative. The AMS operators were owner (44%), successor (44%), wife (6%) and company worker (6%), respectively. The most difficulty (31%) in using AMS was operating the system and complicated program manual. The rate of response to system error and breakdown was 25%. The reasons for culling cow after using AMS were mastitis (28%), reproduction failure (19%), incorrect teat placement (12%), metabolic disease (7%) and others (14%), respectively. Fifty-six percentages of the respondents made AMS maintenance contract and 44% did not. Average annual cost of the maintenance contract was 6,580,000 won. Average score for AMS satisfaction measurement (1 to 5 range) was 3.2 with decrease of labor cost 3.7, company A/S 3.6, increase of milk yield 3.2 and decrease of somatic cell count 2.8, respectively. Suggestions for the higher efficiency in using AMS were selecting cows with correct udder shape and teat placement, proper environment, capital and land, and attitude for continuous observation. Systematic consulting was highly required for AMS companies followed by low cost for AMS setup and systematization of A/S.

• The KIPS Transactions:PartC
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• v.19C no.3
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• pp.191-208
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• 2012

Proxy Mobile IPv6 (PMIPv6) is designed to provide network-based mobility management support to an MN without any involvement of the MN in the mobility related signalling, hence, the proxy mobility entity performs all related signalling on behalf of the MN. The new principal functional entities of PMIPv6 are the local mobility anchor (LMA) and the mobile access gateway (MAG). In PMIPv6, all the data traffic sent from the MN gets routed to the LMA through a tunnel between the LMA and the MAG, but it still has the single point of failure (SPOF) and bottleneck state of traffic. To solve these problems, various approaches directed towards PMIPv6 performance improvements such as route optimization proposed. But these approaches add additional signalling to support MN's mobility, which incurs extra network overhead and still has difficult to apply to multiple-LMA networks. In this paper, we propose a improved route optimization in PMIPv6-based multiple-LMA networks. All LMA connected to the proxy internetworking gateway (PIG), which performs inter-domain distributed mobility control. And, each MAG keeps the information of all LMA in PMIPv6 domain, so it is possible to perform fast route optimization. Therefore, it supports route optimization without any additional signalling because the LMA receives the state information of route optimization from PIG.

• Journal of Navigation and Port Research
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• v.37 no.1
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• pp.113-121
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• 2013

IMO(International Maritime Organization) is existed the movement for revising ISM Code so that the maintenance history and the trouble information given trading in a ship can be transferred. An empirical analysis was made on the influence that will have upon shipping industry through surveying on the recognition on ISM Code revision in employees of the relevant field and on the expected problems given being amended ISM Code as the above. In conclusion, the positive effect is judged to be more in the aspect of ship safety, which is the aim of ISM Code, rather than the negative effect, which may take place given being revised ISM Code. In other words, the clean market can be formed through this because fairness is maintained on both sides given trading in a ship by which opening the maintenance record and the trouble history is applied equally to a buyer and a seller. Ships can be reduced a loss of time and cost in preventing similar problems and seeking solution that may appear in important equipments, through this maintenance record. Also, based on these materials, it comes to be available for analyzing a risk of ship and preventing and managing a risk, thereby being increased ability of maintenance and repair in a ship, resulting in being judged to likely contributing to ship safety and environmental-pollution prevention.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.11
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• pp.256-264
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• 2020

Industrial Wireless Sensor Networks (IWSNs) is exploited to achieve various objectives such as improving productivity and reducing cost in the diversity of industrial application, and it has requirements such as low-delay and high reliability packet transmission. To accomplish the requirement, the network manager performs graph construction and resource allocation about network topology, and determines the transmission cycle and path of each node in advance. However, this network management scheme cannot treat mobile devices that cause continuous topology changes because graph reconstruction and resource reallocation should be performed as network topology changes. That is, despite the growing need of mobile devices in many industries, existing scheme cannot adequately respond to path failure caused by movement of mobile device and packet loss in the process of path recovery. To solve this problem, a network management scheme is required to prevent packet loss caused by mobile devices. Thus, we analyse the location and movement cycle of mobile devices over time using machine learning for predicting the mobility pattern. In the proposed scheme, the network manager could prevent the problems caused by mobile devices through performing graph construction and resource allocation for the predicted network topology based on the movement pattern. Performance evaluation results show a prediction rate of about 86% compared with actual movement pattern, and a higher packet delivery ratio and a lower resource share compared to existing scheme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.26-32
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• 2016

Usually, there are many uncertainties regarding the error of an assumed load, material properties, member size, and structure analysis in a structure, and it may have a direct influence on the qualities of optimal design of structures. Probabilistic analysis has developed rapidly into a desirable process and structural reliability analysis is an increasingly important tool that assists engineers to consider uncertainties during the design, construction and life of a structure to calculate its probability of failure. This study deals with the applications of two optimization techniques to solve the reliability-based optimization problem of structures. The reliability-based optimization problem was formulated as a minimization of the structural volume subject to the constraints on the values of componential reliability index determined by the AFOSM approach. This presented method may be a useful tool for the reliability-based design optimization of structures.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.275-282
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• 2006

Recently, Fiber Reinforced Polymers(FRP) has been emerged as an alternative material to solve the corrosion of steel reinforcement in reinforced concrete structures. FRP exhibits higher specific strength and lower weight compared to steel reinforcement. Moreover, good resistance to corrosion of the FRP may be useful in aggressive environments causing deterioration such as chloride environment. However, causes for higher initial cost of FRP than that of steel, little information on the long-term behavior of FRP, and brittle failure make the efforts to apply FRP in civil structures slow. Glass fiber among the fibers used to manufacture FRP can be seen as the most beneficial material with regard to initial costs. But its low elastic modulus, which attains barely a quarter of steel, nay thus lead to excessive deflections when used as reinforcement for flexural members. This research was carried out on the tensile properties of hybrid rods made with glass and carbon fibers to improve those of FRP rod made with glass fiber. Parameters were resin type and the arrangement of glass and carbon fibers. The tensile properties of hybrid rods were compared with those of rods manufactured with only glass or carbon fibers. The results indicated that the tensile properties of hybrid rod were good when the carbon fiber was arranged in the core.