• Asian-Australasian Journal of Animal Sciences
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• v.28 no.4
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• pp.592-598
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• 2015

Stress adversely affects the wellbeing of commercial chickens, and comes with an economic cost to the industry that cannot be ignored. In this paper, we first develop an inexpensive and non-invasive, automatic online-monitoring prototype that uses sound data to notify producers of a stressful situation in a commercial poultry facility. The proposed system is structured hierarchically with three binary-classifier support vector machines. First, it selects an optimal acoustic feature subset from the sound emitted by the laying hens. The detection and classification module detects the stress from changes in the sound and classifies it into subsidiary sound types, such as physical stress from changes in temperature, and mental stress from fear. Finally, an experimental evaluation was performed using real sound data from an audio-surveillance system. The accuracy in detecting stress approached 96.2%, and the classification model was validated, confirming that the average classification accuracy was 96.7%, and that its recall and precision measures were satisfactory.

• Journal of Aerospace System Engineering
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• v.6 no.4
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• pp.12-17
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• 2012

This paper is focusing on the define the safety of high speed projectiles from aerodynamic load. The Fin loaded from aerodynamic is the roll of high speed projectile's gide. The Fin can rotate about 25deg as maximum, and it has maximum aerodynamic load with 25deg position. For finite element analysis from aerodynamic load, fluid analysis will be conducted before structure analysis and export pressure data. The pressure data will be used as load condition at structure analysis of Fin. The result of structure analysis of Fin, there is some stress concentration and stress closed with yield stress of material. But this problem will be solved with change to another material.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.3
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• pp.275-286
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• 2007

In construction of a structure in underground space, in-situ stress in rock mass has great effect on the stability of the structure. Especially, the direction and magnitude of rock stress have influence on the excavation method, the choice of support and reinforcement method for establishing the stability of tunnel. Therefore, it is very important to consider the characteristics of in-situ stress in rock mass for tunnel stability analysis. In this study, a reasonable design method for underground structure was reviewed through the case study for tunnel design considering in-situ rock stress. For this purpose, the estimation for SRF (Stress Reduction Factor) as input parameter in rock classification using Q-System and the assesment for tunnel support were studied. Also, considering the characteristics of in-situ rock stress such as the magnitude of K and the direction of principal stress, the parameter studies for tunnel stability analysis were carried out. An improved method was proposed for obtaining the better results in the tunnel stability analysis.

• Journal of the Korean Society for Heat Treatment
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• v.32 no.6
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• pp.270-274
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• 2019

In this study, simulation structure analysis was performed for the differential gear system for passenger cars as a prerequisite for the design of the balancing module. The differential gear system was modeled by using CATIA and simulation structure analysis was performed using ANSYS software. The material of the modeled differential gear system uses the mechanical properties of S45C (Q&T). In the structural analysis of the differential gear, the areas where the maximum stress and the maximum strain occurred can be identified. The maximum stress and maximum strain occurred in the pitch circle of the bevel gear. In evaluating the safety factor, it was found that sufficient safety factor was secured. Based on the analysis results for the differential gear, it is expected that it will be a good reference if we design the balancing module device.

• Journal of the Korean Society of Safety
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• v.21 no.1 s.73
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• pp.6-14
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• 2006

The development of automatic production systems have required intelligent diagnostic and monitoring functions to overcome system failure and reduce production loss by the failure. In order to perform accurate operations of the intelligent system, implication about total system failure and fault analysis due to each mechanical component failures are required. Also solutions for repair and maintenance can be suggested from these analysis results. As an essential component of a mechanical system, a bearing system is investigated to define the failure behavior. The bearing failure is caused by lubricant system failure, metallurgical deficiency, mechanical condition(vibration, overloading, misalignment) and environmental effects. This study described slab transfer equipment fault train due to stress variation and metallurgical deficiency from lubricant failure by using FTA.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.888-892
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• 2003

This study was tested for the bending stress analysis of Experimental stress analysis on various ankle foot orthoses(AFOs) was fulfilled. Stress was measured by Strain gages which were attached on 8 region in AFOs Results revealed that the peak compressive/tensile stress in the orthoses occured in the lateral region of neck. The Stress Analysis system was made by the electronic oscilloscope, strain gage sensors, amplifier, A/D converter, PC with C program It will be able to using the important data in splint design. Selected AFOs were some different materials but all have same shape except one type(orthosis with joint). C program Is used for managing data. Thus lateral side of the neck region is failed easily.

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.80-87
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• 2013

Heat transfer analysis and thermal stress analysis for the concrete bridge was performed in order to investigate the damage of the concrete bridge by the fire of the vehicle. Changes in material properties, such as thermal conductivity, specific heat, density, elasticity, caused by temperature rise were considered. Heat transfer analysis and thermal stress analysis were performed according to the various location of the fire by ABAQUS. From the comparison of the numerical results, the degree of structural damage for the concrete bridge was investigated and considerations for the design of a concrete bridge against fire were identified.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2284-2289
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• 1998

The Rotor Stress Indicator is an integrated system of hardware and program components which has been designed to read an assortment of turbine temperature and speed input devices, perform an analysis of the temperature induced stresses and output pertinent temperature and stress information to guide the turbine operator during turbine prewarming, start-ups, load changes, and shut-downs. The purpose of the RSI is to provide guidance to the plant operator during startup, shutdown, loading, and unloading of the turbine. Since the stresses are a function of the temperature changes to which the turbine is exposed, the RSI also provides guidance for operation of the boiler main steam and reheat steam temperatures as they affect the rotor stresses. This may permit more efficient overall boiler turbine start-ups. In this paper, new rotor stress analysis algorithm for RSI is introduced and compared with present system which has been used in thermal power plant.

• Journal of Acupuncture Research
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• v.21 no.5
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• pp.227-239
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• 2004

Objectives : The purpose of this study was to assess the effect of acupuncture for reducing mental stress using power spectrum analysis of the heart rate variability. Methods : 5 healthy volunteers participated in this study. After instrumentation and 5-minute rest period, mental stress was provided for 5-minute. HRV was recorded before and after the mental stress. Acupuncture was put on the HT8, and needle was removed after 15min. Than 2nd mental stress was given for 5-minute with same method. For the control, same process was repeated to same subject except for acupuncture. Results : After mental stress, LF and LF/HF ratio is significantly increased. After acupuncture treatment, LF/HF ratio is significantly decreased, and LF do not significantly changed despite of mental stress. Conclusions : The result suggest that acupuncture treatment can regulate and prevent the alteration of autonomic nerve system due to mental stress.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.111-116
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• 2008

Since the hydraulic fracturing field testing method was introduced first to Korean geotechnical engineers in 1994, there have been lots of progresses in a hardware system as well as an interpretation tool. The hydrofracturing system of first generation was the pipe-line type, and it has been developed to a wire-line system at their second generation. The current up-to-date system is more compact and is able to be operated by all-in-one system. With a progress in a hardware system, the software for analyzing in-situ stress regime has also been progressed. The shut-in pressure, which is the most ambiguous parameter to be obtained from hydrofracturing pressure curves, can now be acquired automatically from the various methods. While the hardware and software for hydrofracturing tests are being developed during the last decade, the author could accumulate the field test results which can cover the almost whole area of South Korea. Currently these field data are used widely in a feasibility study or a preliminary design step for tunnel construction in Korea. Regarding the difficulties in a site selection and a test performance for the in-situ stress measurement at an off-shore area, the in-situ stress regime obtained from the field experiences in the land area can be used indirectly for the design of a sub-sea tunnel. From the hydrofracturing stress measurements, the trend of magnitude and direction of in-situ stress field was shown identically with the geological information in Korea.