• Journal of Acupuncture Research
• /
• v.22 no.6
• /
• pp.173-180
• /
• 2005

Objectives : The purpose of this study was to assess the effect auricular acupuncture for acute mental stress using power spectrum analysis of the heart rate variability(HRV). Methods : 10 healthy volunteers participated in this study. After 5 minute rest, the first mental stress was provided for 5 minute. And then subjects rested for 15 minute. The second mental stress was provided for 5 minute. The acupoint, Shin-Mun point of the ear was stimulated for 15 minute. HRV was recorded before and after the first and second mental stress, and after auricular acupuncture stimulation. Results : After mental stress, normalized LF and LF/HF ratio is significantly increased. Before and after simple rest, normalized LF and normalized HF is significantly changed, but LF and LF/HF ratio is not significantly changed. On the other hand, before and after auricular acupuncture treatment, normalized LF, normalized HF is significantly changed, and also LF and LF/HF ratio is significantly decreased. Conclusion : The result suggest that auricular acupuncture can decrease more significantly in cardiac sympathetic activity due to mental stress than simple rest.

• The KSFM Journal of Fluid Machinery
• /
• v.19 no.5
• /
• pp.61-67
• /
• 2016

Turbine blade cooling is one of the major technologies to enhance the performance of gas turbine and combined cycle power plants. In this study, two cases of coolant pre-cooling schemes were applied in combined cycle power plant: decrease of coolant mass flow needed to cool turbine blade and increase of turbine inlet temperature (TIT). Both schemes are benefited by the decrease of coolant temperature through coolant pre-cooling. Under the same degree of pre-cooling, increasing TIT exhibits larger plant power boost and higher plant efficiency than reducing coolant flow. As a result, the former produces the same gas turbine power with a much smaller degree of pre-cooling than the latter. Another advantage of increasing TIT is a higher plant efficiency. Even with an assumption of partial achievement of the theoretically predicted TIT, the method of increasing TIT can provide considerably larger power output.

• The KIPS Transactions:PartB
• /
• v.10B no.7
• /
• pp.847-852
• /
• 2003

This paper implements MOD system using multicast delivery. Conventional system provide server-based system in multicast delivery but implemented system provides on-demand client-based multicast system. The scheduler aggregates clients' request and it generate multcast group addresses and port numbers according to requested video items and service request time. Then it transmits immediately multicast address to MOD server and client who request service. And then MOD server transmits requested streams with a multicast group address and the client joins the group automatically. The scheduler assigns the same multicast group address when other clients request an identical video within the same scheduling duration. The system can reduce load of server and support many clients at the same time.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.1
• /
• pp.21-28
• /
• 2004

In the field of content-based image retrieval, many numerical features have been proposed for representing visual image content such as color, torture, and shape. Because the features are assumed to be independent, each of them is extracted without ny consideration of the others. In this paper, we consider the relationship between color and texture and propose a new feature called CCE(channel color energy). Simulation results with natural images show that the proposed method outperforms the conventional regular weighted comparison method and SCFT(sequential chromatic Fourier transform)-based color torture method.

• Physical Therapy Korea
• /
• v.14 no.4
• /
• pp.14-20
• /
• 2007

To improve abdominal muscles strengthening, double straight leg lowering (DSLL) has been widely used in physical therapy, fitness program, and athletic program. The purpose of this study was to investigate the effects of the lumbar stabilization maneuver with a pressure biofeedback unit on the muscle activity of rectus abdominis (RA), external oblique (EO), and internal oblique (IO) during DSLL. Fourteen healthy young men were recruited from university population. The electromyography (EMG) activity was recorded from the RA, EO, and IO of both sides. The normalized EMG activity was compared using a paired t-test. The study showed that EMG activity in the RA, EO, and IO was significantly higher during DSLL with lumbar stabilization (DSLL-LS) compared to performed DSLL (p<.05). These results suggest that DSLL-LS is recommended as an effective method for strengthening exercise for the abdominal muscles.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.1 s.256
• /
• pp.51-61
• /
• 2007

This paper presents numerical and theoretical studies of acoustic wave interactions in slightly compressible liquids within piezoelectrically driven inkjet print heads. The interconnected flow channels may cause jet crosstalk, resulting in poor printing quality. It should be reduced by modifying the channel structure with the acoustic wave interactions considered. Compressible gas flow driven by the sudden movement of a top wall in the channel is calculated using Flow3D and is validated with the narrow gap theory. Limited compressibility model of the Flow3D is employed to calculate pressure waves of slightly compressible ink flow. It is found that reducing restrictor width can damp out the jet crosstalk by inhibiting the pressure wave propagation. The degree of crosstalk has been quantified using the maximum values of cross-correlations between neighboring channels and a critical channel dimension for acceptable crosstalk has been proposed. This finding is verified by drop visualization experiments using silicon-micromachined piezo inkjet print heads that are fabricated by our group.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.5
• /
• pp.639-645
• /
• 2011

Wheel-loader is a construction vehicle for uploading soil or sand into truck and transportation of materials, which requires large driving power and high rotational speed. To improve the working efficiency, the operator has to shift gears and control levers for bucket & boom simultaneously. Therefore, the automatic transmission has been introduced to enhance operator's convenience and enable effective operation. To develop the automatic transmission for the wheel-loader, technologies such as gears and a clutch-pack design and shift algorithm are required for improvement of shift quality. In this paper, the shift algorithm for the wheel-loader was developed and its shift pattern was analyzed. As the shift control is affected by the pressure profile for the clutch control, the shift quality depending on the pressure profile has been evaluated using experiment and simulation model analysis.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.32 no.1
• /
• pp.44-51
• /
• 2009

A bonded warehouse is the warehouse located in bonded area. It functions not only as a general warehouse but also as a place for managing the work related to import and export bonded goods. As a general warehouse, it uses the rack system to store the goods and the folk lift truck to move the unitized goods. The operation of the storing system closely related to the efficiency of space uses in a warehouse and vehicle working. Thus, vehicle performance measured in distance units in the ware-house could be used as one of the key performance measure in warehouse system. This paper focuses on the operation efficiency of the bonded warehouse which uses rack system for the storing and the folk lift truck for moving goods. The method of load allocation for balancing the rack uses and vehicle operation for maximizing efficiency are the specific concerns in this paper. The simulation study is conducted to find a policy for efficient vehicle operation based on balanced rack utilization, and the favorable result for the system operation would lead the usable proposal in vehicle operation.

• Korean Journal of Environmental Biology
• /
• v.25 no.1
• /
• pp.42-55
• /
• 2007

We investigated the species richness of lepidopteran insects (excluding butterflies and microlepidoptera) of Mt. Seungdal-san, Muan-gun, Jeollannam-do, Korea, from 2003 to 2005 using two portable light traps. A total of species comprised 423 species belongs to 17 families were identified. The family Noctuidae with 209 species was dominant in the area followed by Geometridae with 132 species. Based on the number of individuals collected, Geometridae was the highest mostly due to an ennomine species (Alcis angulifera). Monthly fluctuations of moth species richness present an M-shaped curve with two high peaks at June and August. Comparisons of species diversity of yearly captures revealed that the diversity of 2003 was higher than that of 2004, but the diversities of between 2003 and 2005, and between 2004 and 2005 were no different.

• Journal of Sensor Science and Technology
• /
• v.20 no.3
• /
• pp.199-206
• /
• 2011

Sell call radio buoy is mostly used for searching for the location of fishing nets. Sell call radio buoy for the detection of the code uses the band pass filter(BPF). All BPF is used by imported from Japanese companies. But, Japanese companies stopped selling buoys for searching for the location of fishing nets, and domestic manufacturing companies could not sell buoys any more. Therefore, In this paper, a new method to replace the conventional buoy code detector is proposed. The proposed methods are constructed with an analog filter division composed of BPFs and notch filters as well as a microprocessor with analog digital converters. The advantage of proposed methods is able to combine various codes, can enhance receiver sensitivity. The experimental results confirm the usefulness of the proposed method.