• Journal of the Korean Wood Science and Technology
• /
• v.48 no.4
• /
• pp.562-568
• /
• 2020

This study investigates the relationship between ultrasonic velocity and density in the direct method, the effect of distance between transducers in the indirect method, and the difference between the direct and indirect methods with transducers placed at a distance of 200 mm in nondestructive ultrasonic testing of spruce lumber. The direct method using 54 kHz ultrasonic transducers was applied to two planes, namely, radial section (LR) and tangential section (LT) of samples. The indirect method measurements were taken using the same transducers. Two velocities were measured at the top and bottom of the LT plane and at the two sides of the LR plane; the two values for each plane were averaged. The relationship between density and ultrasound velocity in the direct method demonstrated a positive correlation between the two variables. The difference between the two planes, LT and LR, was not statistically significant. Moreover, the distance between the transducers in the indirect method affected ultrasound velocity, with the ultrasonic velocity increasing as the distance between the transducers became larger. A transducer distance of 200 mm yielded a close approximation of the direct method results with a ratio of 0.87. Finally, no statistical evidence of a difference between the two planes in the indirect method was found. If the direct method, which requires access to two surfaces, is impractical, the indirect method can be applied.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.8
• /
• pp.87-94
• /
• 2020

The paper aims to investigate the impact of presenting statements of cash flow using the direct method and the indirect method on loan decision by credit officers at Vietnamese banks. The data was collected from 150 credit officers of commercial banks in Vietnam based on the questionnaire about making loan decision when the cash flow statement is presented in different methods, namely, direct and indirect methods. This research uses T-tests to check whether using the direct or indirect method affects the accurate calculation of loan criteria, affects the loan decision by credit officers, and compare these two methods in the aspects of information provision. The research has pointed out that: 1) the direct method helps the calculation of indicators related to loans more accurately; 2) credit officers say that, while the direct method of presenting cash flow statement provides clearer information, the use of either the direct method or the indirect method does not affect the banks' loan decision. Since then, the author recommends that cash flow statements should be provided with information in a direct method to present the information needed for loan decision more accurately so as to improve the quality of cash flow statement.

• Journal of Drive and Control
• /
• v.11 no.4
• /
• pp.8-14
• /
• 2014

The transmission control method of a small forklift is classified into a pilot control method and a direct control method. In the pilot control method, the complex hydraulic circuit consists of many components, making the production process too costly and time consuming. The direct control method contains fewer components that can be configured to simple hydraulic circuits. As another advantage, the input profile easily changes the shift sensitivity of the transmission. Therefore, this research considers the characteristics of the direct control method in the development of hydraulic system design. This paper will present a simulation of the direct control transmission using AMESim. First, modeling of the direct control method is obtained and simulated with real parameters. The simulation results then are carried out and compared with the experimental results to verify and analyze the characteristics of the direct control method.

• ETRI Journal
• /
• v.45 no.3
• /
• pp.394-403
• /
• 2023

Direct tracking problem of moving noncircular sources for multiple arrays is investigated in this study. Here, we propose an improved unscented particle filter (I-UPF) direct tracking method, which combines system proportional symmetry unscented particle filter and Markov Chain Monte Carlo (MCMC) algorithm. Noncircular sources can extend the dimension of sources matrix, and the direct tracking accuracy is improved. This method uses multiple arrays to receive sources. Firstly, set up a direct tracking model through consecutive time and Doppler information. Subsequently, based on the improved unscented particle filter algorithm, the proposed tracking model is to improve the direct tracking accuracy and reduce computational complexity. Simulation results show that the proposed improved unscented particle filter algorithm for noncircular sources has enhanced tracking accuracy than Markov Chain Monte Carlo unscented particle filter algorithm, Markov Chain Monte Carlo extended Kalman particle filter, and two-step tracking method.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2008.11a
• /
• pp.13-16
• /
• 2008

This paper is to present the performance data for improved direct setting method using tile bond for application of porcelain tile under 1 percent absorptance. For this purpose, improved direct setting method type 1 & 2(tile bond curing time 0, 24H) were compared with the conventional setting methods(including direct setting method and improved pressure setting method) in the sight of the adhesive stability of porcelain tile. It tested for tiles after 14, 28days under standard condition and severe conditions. The severe conditions were water immersion, heat ageing(70℃) and freeze-thaw cycle. On the basis of test results, the adhesive strength of direct setting method was lowest for the conventional setting methods. But improved direct setting method using tile bonds(A, B) came close to the result of improved pressure setting method using tile bonds.

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.231-234
• /
• 1997

This paper presents improved direct method for calculating the closest saddle node bifurcation (CSNB) point, which is also applicable to the selection of appropriate load shedding, reactive power compensation point detection. The proposed method reduced dimension of nonlinear equation compared with that of Dobson's direct method. The improved direct method, utilizing Newton Iterative method converges very quickly. But it diverges if the initial guess is not very close to CSNB. So the direct method is performed with the initial values obtained by carrying out the iterative method twice, which is considered most efficient at this time. Since sparsity techniques can be employed, this method is a good choice to a large scale system on-line application. Proposed method has been tested for 5-bus, New England 30-bus system.

• Journal of Korea Multimedia Society
• /
• v.24 no.2
• /
• pp.167-177
• /
• 2021

In the field of augmented reality, edge-based methods have been popularly used in tracking textureless 3D objects. However, edge-based methods are inherently vulnerable to cluttered backgrounds. Another way to track textureless or poorly-textured 3D objects is to directly align image intensity of 3D object between consecutive frames. Although the direct methods enable more reliable and stable tracking compared to using local features such as edges, they are more sensitive to occlusion and less accurate than the edge-based methods. Therefore, we propose a method that combines an edge-based method and a direct method to leverage the advantages from each approach. Experimental results show that the proposed method is much robust to both fast camera (or object) movements and occlusion while still working in real time at a frame rate of 18 Hz. The tracking success rate and tracking accuracy were improved by up to 84% and 1.4 pixels, respectively, compared to using the edge-based method or the direct method solely.

• Steel and Composite Structures
• /
• v.29 no.4
• /
• pp.509-526
• /
• 2018

The direct strength method adopted by the AISI Standard and AS/NZS 4600 is an advanced design method meant to substitute the effective width method for the design of cold-formed steel structural members accounting for local instability of thin plate elements. It was proven that the design strength formula for the direct strength method could predict the ultimate strength of medium strength steel welded section compressive and flexural members with local buckling reasonably. This paper focuses on the modification of the direct strength formula for the application to high strength and high performance steel welded section columns which have the nominal yield stress higher than 460 MPa and undergo local buckling, overall buckling or their interaction. The resistance of high strength steel welded H and Box section columns calculated by the proposed direct strength formulae were validated by comparison with various compression test results, FE results, and predictions by existing specifications.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.3 no.1
• /
• pp.30-47
• /
• 2001

This research was performed to develope a stable direct seeding method in rice cultivation using by a direct seeder with soil application. A principle of this methodology was introduced from seeding nursery system of machine transplanting enable to increase high seeding establishment direct seeding method with soil application was high of 89-95% while that of water seeding was 68%. During seeding growth plant height was ralatively small but seeding health was high. A total soil consumption of this methodology was 145kg/10a in dirll seeding and 26kg/10a in hill seeding respectively, there was 100% erected in direct seeding with soil application while water seeding was 45% in erected seeding stand. In direct seeding method with soil application total carbohydrate content was higher than that of water seeding. This machine was manufactured to attach and/or detach to a machine transplanter with riding type and machine cultivator with multipurpose. In the farmer's demonstrated rice field this method was well performed like machine transplanting in terms of rice growth and development. There was highly cost reduction for rice production like other direct seeding methods.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.2
• /
• pp.55-64
• /
• 2010

This study tried to focus on nontraditional job that has not been studied in terms of the subjects associated with MSDs(Musculoskeletal Disorders). Specifically, dental procedure was the job to be analyzed in this study. An alternative method as well as a traditional method for viewing teeth while performing simulated dental procedures. Four graduated students did both methods(direct view and indirect view) as the subjects in this study. The method based on indirect view used a video camera and monitor to view the teeth. The experiment was conducted five times for each subject. The major findings in this study were as follows; 1) Job speed was increased with the repetitions for both methods, 2) Difference of Neck flexion between direct and indirect methods was statistically siginificant(Neck flexion for indirect method was dramatically decreased), 3) Difference of job speed between direct and indirect methods was statistically significant(Job speed for direct method was faster than that of indirect method), 4) Difference of error rate between direct and indirect methods was statistically significant(error rate for direct method was lower than that of indirect method), 5) Even though indirect method did not provide better performance in terms of job speed and error rate yet, it seemed to need a trade-off between two methods in the future since indirect method provided better working postures than that of direct method.