• Steel and Composite Structures
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• v.43 no.1
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• pp.107-116
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• 2022

This paper presents results of numerical studies completed on unreinforced and doubler plate reinforced Elliptical Hollow Section (EHS) T-joints subjected to axial compressive loading on the brace member. Non-linear finite element (FE) models were developed using the finite element code, ABAQUS. Available test data in literature was used to validate the FE models. Subsequently, a parametric study was carried out to investigate the effects of various geometrical parameters of main members and reinforcement plates on the ultimate capacity of reinforced EHS T-joints. The parametric study found that the reinforcing plate significantly increases the ultimate capacity of EHS T-joints up to twice the capacity of the corresponding unreinforced joint. The thickness and length of the reinforcing plate have a positive effect on the ultimate capacity of Type 1 joints. This study, however, found that the capacity of Type 1 orientation is not dependent on the brace-to-chord diameter ratio. As for type 2 orientations, the thickness and length of the reinforcement have a minimal effect on the ultimate capacity. A new design method is introduced to predict the capacity of the reinforced EHS T-joints Type 1 and 2 based on the multiple linear regression analyses.

• East Asian Journal of Business Economics (EAJBE)
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• v.10 no.3
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• pp.51-61
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• 2022

Purpose - The purpose of this study is to establish the government's logistics policy by calculating the logistics cost of the company and grasping the management status, to reduce the logistics cost of the related companies and to provide basic statistical data necessary for the management strategy. This work examines some associations between reasons for reducing corporate logistics costs (RCLC) and corporate classification such as industry and sales size. Research design, data, and methodology - The survey was conducted in 2018 for 2,000 companies based on the business of mining, manufacturing and wholesale and retail industries since 2010. The survey population is 94,976, of which 92,708 are small and medium enterprises and 2,268 are large corporations. The association among factors may be statistically and visually explored by using chi-squared test and correspondence analysis. Result - This study reveals the association between reasons for RCLC and corporate classification and properties and closeness that exist between the categories of each factor can be mined. Conclusion - As a task to reduce logistics costs of industrial products, expansion and operation of joint logistics business, establishment of cooperative logistics network, and establishment of ordinance on support for smart distribution logistics can be proposed.

• The Journal of Korea Robotics Society
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• v.17 no.4
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• pp.438-446
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• 2022

In this paper, we propose an intelligent three-legged landing system that can maintain stability and level even on rough terrain than conventional four-legged landing systems. Conventional landing gear has the limitation that it requires flat terrain for landing. The 3-leg landing system proposed in this paper extends the usable range of the legs and reduces the weight, allowing the quadcopter to operate in various environments. To do this, kinematics determine the joint angles and coordinates of the legs of the two-link structure. Based on the angle value of the quadcopter detected via the IMU sensor, the leg control method that corrects the posture is determined. A force sensor attached to the end of the leg is used to detect contact with the ground. At the moment of contact with the ground, landing control starts according to the value of the IMU sensor. The proposed system verifies its reliability in various environments through an indoor landing test stand. Finally, in an outdoor environment, the quadcopter lands on a 20 degree incline and 20 cm rough terrain after flight. This demonstrates the stability and effectiveness of the 3-leg landing system even on rough terrain compared to the 4-leg landing system.

• Clinics in Shoulder and Elbow
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• v.25 no.1
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• pp.42-48
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• 2022

Background: Total shoulder arthroplasty (TSA) has been demonstrated to be an effective treatment for multiple shoulder pathologies. The purpose of our study was to compare the relative value units (RVUs) per minute of surgical time for primary and revision TSA. Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried to identify patients that underwent primary TSA, one-component revision TSA, and two-component revision TSA between January 1, 2015 and December 31, 2017 using current procedure terminology codes. RVUs were divided by mean operative time for each procedure to determine the amount of revenue generated per minute. Rates were compared between the groups using a one-way analysis of variance with post-hoc Tukey test. Statistical significance was set at p<0.05. Results: When dividing compensation by surgical time, we found that two-component revision generated more compensation per minute compared to primary TSA (0.284±0.114 vs. 0.239±0.278 RVU per minute or $10.25±$4.11 vs. $8.64±$10.05 per minute, respectively; p=0.001). Conclusions: The relative value of revision TSA procedures is weighted to account for the increased technical challenges and time associated with these procedures. This study confirms that reimbursement is higher for revision TSA compared to primary TSA.

• Structural Engineering and Mechanics
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• v.84 no.5
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• pp.591-604
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• 2022

A gravity wall combined with an anchoring lattice frame (a combined retaining structure) is adopted at a typical engineering site at Dali-Ruili Railway Line China. Where, the combined retaining structure supports a soil deposit covering on different inclined rock slopes. With an aim to investigate and compare the effects of inclined rock slopes on the response of combined retaining structure under seismic excitation, three groups of shaking table tests are conducted. The rock slopes are shaped as planar surfaces inclined at angles of 20°, 30°, and 40° with the horizontal, respectively. The shaking table tests are supplemented by dynamic numerical simulations. The results regarding the horizontal acceleration response, vertical acceleration response, permanent displacement mode, and axial anchor force are comparatively examined. The acceleration response is more susceptible to outer structural profile of combined retaining structure than to inclined angle of rock slope. The permanent displacement decreases when the inclined angle of the rock slope increases within a range of 20°-40°. A critical inclined angle of rock slope exists within a range of 20°-40°, and induces the largest axial anchor force in the combined retaining structure.

• The Journal of Korea Robotics Society
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• v.18 no.3
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• pp.241-250
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• 2023

This paper describes the posture stabilization control of a bipedal transformer robot being developed for military use. An inverted pendulum model with a rectangular that considers the robot's inertia is proposed, and a posture stabilization moment that can maintain the body tilt angle is derived by applying disturbance observer and state feedback control. In addition, vertical force and posture stabilization moments that can maintain the body height and balance are derived through QP optimization to obtain the necessary torques and vertical force for each foot. The roll and pitch angles of the IMU sensor attached to the robot's feet are reflected in the ankle joint to enable flexible adaptation to changes in ground inclination. Finally, the effectiveness of the proposed algorithm in posture stabilization is verified by comparing and analyzing the difference in body tilt angle due to disturbances and ground inclination changes with and without algorithm application, using Gazebo dynamic simulation and a down-scale test platform.

• Journal of Powder Materials
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• v.30 no.4
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• pp.339-345
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• 2023

This study investigates the melting point and brazing properties of the aluminum (Al)-copper (Cu)-silicon (Si)-tin (Sn) alloy fabricated for low-temperature brazing based on the alloy design. Specifically, the Al-20Cu-10Si-Sn alloy is examined and confirmed to possess a melting point of approximately 520℃. Analysis of the melting point of the alloy based on composition reveals that the melting temperature tends to decrease with increasing Cu and Si content, along with a corresponding decrease as the Sn content rises. This study verifies that the Al-20Cu-10Si-5Sn alloy exhibits high liquidity and favorable mechanical properties for brazing through the joint gap filling test and Vickers hardness measurements. Additionally, a powder fabricated using the Al-20Cu-10Si-5Sn alloy demonstrates a melting point of around 515℃ following melting point analysis. Consequently, it is deemed highly suitable for use as a low-temperature Al brazing material.

• Steel and Composite Structures
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• v.48 no.5
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• pp.547-564
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• 2023

This study investigates the effect of bolt preloading on the rotational stiffness of stainless steel end-plate connections. An experimental programme incorporating 11 full-scale joint specimens are carried out comparing the behaviours of fully pre-tensioned (PT) and snug-tightened (ST) flush/extended end-plate connections, made of austenitic or lean duplex stainless steels. It is observed from the tests that the presence of bolt preloading leads to a significant increase in the rotational stiffness. A parallel finite element analysis (FEA) validated against the test results demonstrates that the geometric imperfection of end-plate has a strong influence on the moment-rotation response of preloaded end-plate connections, which is crucial to explain the observed "two-stage" behaviour of these connections. Based on the data obtained from the tests and FE parametric study, the performance of the Eurocode 3 predictive model is evaluated, which exhibits a significant deviation in predicting the rotational stiffness of stainless steel end-plate connections. A modified bi-linear model, which incorporates three key properties, is therefore proposed to enable a better prediction. Finally, the effect of bolt preloading is demonstrated at the system (structure) level considering the serviceability of semi-continuous stainless steel beams with end-plate connections.

• International journal of advanced smart convergence
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• v.12 no.1
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• pp.157-163
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• 2023

The current research aims to examine the moderating effect of consumers' mindset on their product purchase intention in the multi-promotion offers containing both a bonus pack and a price discount (i.e., BP + PD offers). That is, this research investigateswhether consumers' product purchase intention in the BP + PD offers variesdepending on their mindset (growth mindset vs. fixed mindset). Specifically, it is predicted that consumers with a fixed mindset will have higher product purchase intention in the offers containing the high PD but low extra amount of BP (LBP HPD) than in the offers with a high extra amount of BP but low PD (HBP LPD), whereas consumers with a growth mindset will have higher product purchase intention in the HBP LPD offers than in the LBP HPD offers. An experiment wasconducted to test the prediction. Consistent with the prediction, it was found that participants' mindset moderates their product purchase intention in multi-promotion offers. The findings imply that marketers can evoke more positive consumer purchase intention toward BP and PD offers, considering consumer mindset.

• Korean Journal of Head & Neck Oncology
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• v.39 no.1
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• pp.27-31
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• 2023

Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis, is a rare immunological small vessel disease which usually affects respiratory tract and kidneys. However, salivary gland involvement in GPA is rare as a primary manifestation. We report a case of GPA with the primary presentation of submandibular gland involvement. A 48-year-old female patient presented submandibular swelling with a skin defect that lasted for 1 month. Although the biopsy result was chronic inflammation, the skin defect did not heal for a month. Further imaging study revealed multiple lung and renal masses. More clinical manifestations such as gingivitis, ischemic change of finger joint and nasal tip skin, and positive c-ANCA test was presented. Additional biopsy was made at the submandibular gland, lung, and finger skin. The patient was finally diagnosed with GPA and treated with steroid pulse therapy and cyclophosphamide. The patient showed improvement of prior clinical symptoms.