• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.91-107
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• 2002

This research got the following conclusion as result that analyzed high clear action kinematically to 4 C girls' junior high school badminton players who are situated in Chungchong-bukdo. 1. Most of the subject didn't rotate their right shoulder and elbow joint at back swing and moved speedy to shuttle cock. And an cooperation action of joint decreases displaying only a good action on both subject`s specification joint part. 2. When the subject S1 and S2 swing slowly and largely the joint of shoulder and elbow and then the speed of right wrist and racket head is fast, the cooperation action of joint is better than other subject. 3. An angle change of right shoulder showed angle that all subjects are great being caused in softness of joint and angular velocity was exposed that load enough Impact force and increase the speed of racket head as angular velocity decreases rapidly in Impact except subject S3. 4. All subjects of right elbow angle change showed similar form and was exposed that subject S2 sees form of impact stage serious bends from back swing and do not use force effectively in angular velocity. 5. Angle of right wrist appeared that the speed of shuttle cock is decelerated because fast bends of wrist is not formed shortly after Impact because all subject do not accomplish big angle shortly after back swing. Angular velocity can assume that the subject S1 and S4 are using and move fast strong snap shot offering angular velocity value of Impact stage sound (-). 6. While size of Impact stage knee angle accomplishes angle that is big both subject, hip joint angles sees small angle and is playing swing that do on upper body and arm without using strong waist force that is composition action with knee and hip joint.

• Earthquakes and Structures
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• v.17 no.4
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• pp.411-424
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• 2019

In this study, a numerical model of a shield tunnel with an assembled segmental lining was built. The seismic response of the segmental lining of the section of the shield tunnel in Line 1 of the Chengdu Metro is analyzed as it passes through the interface of sand-cobble and mudstone layers. To do so, the node-stress seismic-motion input method was used to input the seismic motion measured during the 2008 Wenchuan earthquake, and the joint openings and dislocations associated with the earthquake action were obtained. With reference to the Ethylene-Propylene-Diene Monomer (EPDM) sealing gaskets used in the shield tunnels in the Chengdu Metro, numerical simulation was applied to analyze the contact pressure along the seepage paths and the waterproof property under different joint openings and dislocations. A laboratory test on the elastic sealing gasket was also conducted to study its waterproof property. The test results accord well with the numerical results and the occurrence of water seepage in the section of the shield tunnel in Line 1 of the Chengdu Metro during the 2008 Wenchuan earthquake was verified. These research results demonstrate the deformation of segmental joint under earthquake, also demonstrate the relationship between segmental joint deformation and waterproof property.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.311-325
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• 2003

A relation between the movement range of arms and arising moment has been studied to find out efficient movement range to minimize impact concerning arm landing in sports aerobics. Four male athletes who won top three in national-level sports aerobics competition were chosen for the experiment. They were allowed to jump in between two force platform so that the right hand and the right leg could land onto the front and rear force platform, respectively. The sampling frequency was 200 Hz. The main conclusions based on the analysis of the angle and joint moment parameters of wrist, elbow, and shoulder are as follows: 1. The wrist moment was small when its angle was small, indicating that the dorsi-flexion of the wrist joint offered a positive influence to reduce wrist moment. 2. The elbow angle increased as wrist angle decreased and vice versa. This means that the movement range of the wrist joint affects that of the elbow joint. The darsi-flexion of the wrist is the position to absorb the impact of the elbow effectively rather than to absorb the impact of the wrist itself. The impact is absorbed by the flexion of wrist joint rather than the wrist. 3. The degree of moment transfer of the shoulder joint, having absorbed the impact from the elbow and elbow joint, became dependent on the efficiency of the fore-joints impact absorption.

• Korean journal of applied entomology
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• v.19 no.2 s.43
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• pp.73-78
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• 1980

Some experiment were conducted to evaluate the joint toxic action of carbofuran(2,3-Dihydro-2, 2-dimethyl-benzofuranyl methyl carbamate) and diazinon (0.0-Diethyl-0-(2-isopropyl-6-methyl-e-pyrimidinyl)-0-thionophosphate) against 3rd-instar larvae of the common cutworm, Agrotis fucosa (Butler). Acetone solutions of carbofuran or diazinon or mixture of these two insecticides, were topically applied to the mesonotum of the insect in a constant volume of $1.0{\mu}l$ per larva by means of Burkard microapplicator. Joint toxic action of carbofuran and diazinon for 3rd-instar larva of common cutworm was synergistic. The maximum synergistic effect might be obtained when the ratio of carbofuran to diazinon was 4.8 : 5.2.

• Structural Engineering and Mechanics
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• v.16 no.5
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• pp.581-595
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• 2003

Since the conventional direct approaches are hard to be applied for damage diagnosis of complex large-scale structures, a two-step approach for diagnosing the joint damage of framed structures is presented in this paper by using artificial neural networks. The first step is to judge the damaged areas of a structure, which is divided into several sub-areas, using probabilistic neural networks with natural Frequencies Shift Ratio inputs. The next step is to diagnose the exact damage locations and extents by using the Radial Basis Function (RBF) neural network with the second Element End Strain Mode of the damaged sub-area input. The results of numerical simulation show that the proposed approach could diagnose the joint damage of framed structures induced by earthquake action effectively and has reliable anti-jamming abilities.

• Journal of the Korean Wood Science and Technology
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• v.17 no.4
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• pp.35-43
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• 1989

Nailed joints, which are commonly used in Wooden structures, transmit loads from one member to another and induce partial composite actions between members. Long-term loads induce creep slip in nailed joints and affect load sharing and partial composite action, which may reduce joint stiffness. Two theoretical viscous-viscoelastic models were developed for nailed joints to predict creep behavior under long-term variable loads. Those models were also used to predict stiffness changes under long-term variable loads. The stiffness of nailed joint is defined as a Secant modulus which is called the joint modulus or slip modulus. Input data for the models are the results of constant load tests under three different load levels. To verify the models, nailed joints were also tested under two long-term variable load functions. The predictions of the models were very close to the experimental data. Therefore, the theoretical viscous-viscoelastic models and procedures developed in this study can be applied to predict creep slip and the changes in joint moduli of nailed joints under long-term variable loads.

• Journal of Welding and Joining
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• v.16 no.4
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• pp.117-124
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• 1998

During the reflow process in SMT, the molten solder has been observed to move upward and solidify along the gullwing lead, which is called the wicking phenomenon. In this paper, possible causes of the wicking are investigated, and its effects on the solder joint profile are quantitatively estimated by introducing the wicking constant. The free energy reduction by intermetallic formation between the copper and tin seems to be the major source of wicking action. The joint profiles of the gullwing lead are calculated using the previous finite element formulation incorporated with the wicking constant. The calculated results show reasonably good agreements with the experimental data when the wicking effects are considered.

• Journal of Computational Design and Engineering
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• v.1 no.1
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• pp.55-66
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• 2014

A knee joint's longevity depends on the proper integration of structural components in an axial alignment. If just one of the components is abnormally off-axis, the biomechanical system fails, resulting in arthritis. The complexity of various failures in the knee joint has led orthopedic surgeons to select total knee replacement as a primary treatment. In many cases, this means sacrificing much of an other-wise normal joint. Here, we review novel computational approaches to describe knee physiotherapy by introducing a new dimension of foot loading to the knee axis alignment producing an improved functional status of the patient. New physiotherapeutic applications are then possible by aligning foot loading with the functional axis of the knee joint during the treatment of patients with osteoarthritis.

• ETRI Journal
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• v.41 no.4
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• pp.494-505
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• 2019

In this paper, we propose a new framework for detecting the unauthorized dumping of garbage in real-world surveillance camera. Although several action/behavior recognition methods have been investigated, these studies are hardly applicable to real-world scenarios because they are mainly focused on well-refined datasets. Because the dumping actions in the real-world take a variety of forms, building a new method to disclose the actions instead of exploiting previous approaches is a better strategy. We detected the dumping action by the change in relation between a person and the object being held by them. To find the person-held object of indefinite form, we used a background subtraction algorithm and human joint estimation. The person-held object was then tracked and the relation model between the joints and objects was built. Finally, the dumping action was detected through the voting-based decision module. In the experiments, we show the effectiveness of the proposed method by testing on real-world videos containing various dumping actions. In addition, the proposed framework is implemented in a real-time monitoring system through a fast online algorithm.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.3
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• pp.373-392
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• 2018

The emission of air pollutants in China has increased rapidly as its economy expanded over the last decades. The Chinese government has recently acknowledged the seriousness of the resulting air pollution and is trying to improve air quality in many ways. Here, we review the air quality control and management policies in China, one of our closest neighbors, because these policies may also influence the air quality in Korea. This study examined the recent policies on $PM_{2.5}$ reduction and analyzed the variation in air quality and air pollutant emissions in China. The ambient air quality and emission standards in China have been strengthened, based on China's Air Pollution Prevention and Control Action Plan of 2013. As a result, the annual mean concentration of $PM_{2.5}$ in 2015 in 74 large Chinese cities declined by 23.6% compared with 2013 values. Coal consumption in China also has been reduced by more than 10% per year since 2013. Furthermore, the laws controlling atmospheric emissions were revised again in 2016, and an air pollution forecasting and warning system was implemented to help manage air pollution problems. At present, the Chinese government is trying to evaluate its policies on $PM_{2.5}$ and find a new paradigm to mitigate ongoing $PM_{2.5}$ pollution. In this context, a joint study between Korea and China has been initiated to investigate the characteristics and sources of ambient $PM_{2.5}$ and to identify factors contributing to the high $PM_{2.5}$ concentrations in northeast China. We expect that this academic collaboration will benefit both countries in their search for new policies for $PM_{2.5}$ reduction.