• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.6
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• pp.560-565
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• 2005

This paper deals with the development of manually operated die used for the manufacture of octagonal boxes into two sets of automated die. In particular, theoctagonal boxes are used fur the switch boxes intended fur the cable conduit of buildings or f3r wiring connection. Manufacturing these boxes requires forming the materials using the primary press before they undergo 2nd through 6th processing by the press machine including the four sides of the octagonal outlet box and bending. Such complicated process hikes up labor cost, slows down production, and results in defect rate of $10\%$ or higher; hence the overall rise in manufacturing cost. Moreover, workers avoid this type of work due to the roar and vibration coming from the press and the risk of accident. To eliminate such phenomenon, a CAM die made by integrating five sets of die into one set of die and an automatic conveyor system were developed. As a result, unmanned work was realized with only two units of press and two sets of die; thus solving the problem of work being avoided and saving on manufacturing cost.

• The Journal of the Korean dental association
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• v.49 no.4
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• pp.219-226
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• 2011

Snoring and obstructive sleep apnea (OSA) are common sleep disordered breathing conditions. Habitual snoring is caused by a vibration of soft tissue of upper airway while breath in sleeping, and obstructive sleep apnea is caused by the repeated obstructions of airflow for a sleeping, specially airflow of pharynx. Researchers have shown that snoring is the most important symptom connected with the obstructive sleep apnea syndrome The treatment is directed toward improving the air flow by various surgical and nonsurgical methods. The current surgical procedures used are uvulopalatopharyngoplasty(UPPP), orthognathic surgery, nasal cavity surgery. Among the nonsurgical methods there are nasal continuous positive air pressure(CPAP), pharmacologic therapy. weight loss in obese patient, oral appliance(sleep splint). Sleep splint brings the mandible forward in order to increase upper airway volume and prevents total upper airway collapse during sleep. However, the precise mechanism of action is not yet completely understood, especially aerodynamic factor. The aim of this study evaluated the effect of conservative treatment of snoring and OSAS by sleep splint through measured aerodynamic change by an aerophone II. We measured a airflow, sound pressure level, duration, mean power from overall airflow by aerophone II mask. The results indicated that on a positive correlation between a decrease in maximum airflow rate and a decrease in maximum sound pressure level, on a negative correlation between a decrease in maximum airflow rate and a increase in duration.

• The Korean Fashion and Textile Research Journal
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• v.16 no.1
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• pp.55-65
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• 2014

This study analyzes music visualization characteristics in modern fashion based on Wassily Kandinsky's music visualization theory. Alexander McQueen's 2014 Spring Ready-to-wear Collection (as inspired by Mondrian's paintings) was selected as the research subject. First, an analysis of Mondrian's paintings based on Wassily Kandinsky's theory shows that music visualization characteristics can be categorized into spatiality, mobility, and duality. Second, McQueen applied Mondrian's paintings to the overall design, structured the model's shape in the painting, or created patterns using colors and lines that introduced them in clothes; symbolic forms were also introduced as part of or a decorative factor of the clothes. Third, spatiality refers to the creation of a feeling of space through emptiness or fill using lines, colors, and shape. Musical atmosphere such as dissonance were expressed in clothing through the application of color contrast, lines and silhouette dynamics, and symbolic format and patterns by Mondrian. Fourth, mobility generally refers to motion caused by a certain stimulus. Mondrian expressed vibration, internal resonance, sound level in music that emphasized color irregularity, primary color contrast, and rough brush touches as well as free and organic patterns. McQueen expressed this with primary color contrast using different materials, rough touch based on texture, and pattern repetition through transformation. Fifth, duality generally refers to the artistic effect caused by overlap. Mondrian created a resemblance of dissonance and music through line and color as expressed through the duality of clothing design components based on the artistic sense of the designer.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1521-1527
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• 2010

Since inkjet printing is being employed in production lines of electronics and display industries, the tack time for inspection of jetting failure has become very important because the throughput of the inkjet printing system can be extended to the maximum limit by adopting a shorter jetting inspection time. The most popular method for inspecting jetting failure involves the use of a linear stage, a high magnification lens, and a charge coupled devicecamera. However, this conventional approach requires approximately 60 s to complete the jetting inspection and might not be suitable for a high-speed reciprocating jetting inspection in endurance tests due to the unwanted mechanical vibration. In this study, a novel concept of an inkjet monitoring module is introduced, which has an overall inspection time of 18 s. For the shorter tack time of jetting inspection, the parameters affecting the tack time are discussed in this paper.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.106-113
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• 2008

The starter motor noise is usually well identified by the customers since it is operated while the engine is quiet, and leaves distinct impressions of the vehicle. In this study the design of experiments(DOE) was applied to the identification of the noise sources of direct drive starter motor since this process usually requires lengthy analysis and elaborate experiments. In the first stage of the test, five controllable factors(alignment and dynamic unbalance of armature, tightening torques of T/bolt and center bracket bolt, and alignment of the center bracket-yoke-rear bracket), excluding static unbalance, are sorted out of all possible factors. Test results showed that the dynamic unbalance and misalignment of armature are the major factors. However, the error level of the first test was relatively high, indicating that there might be some missing major factors. In the second stage test the results showed that both static and dynamic unbalances are the dominant factors contributing to more than 80% of the overall noise, while the misalignment contributes around 12%. Error of the second test was about 4% that could be considered satisfactory. The noise level of the optimal product was predicted to be reduced by 19dBA, and verification test showed the average noise reduction of 16.8dBA with the standard deviation of 3.2dBA, and proved the usefulness of the whole DOE process.

• Journal of environmental and Sanitary engineering
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• v.1 no.1 s.1
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• pp.81-96
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• 1986

510 random samples were studied during the months of may through November 1985 at the various industries and conclustions were made as follows; 1. $43.94\%$ of the plants studied operated their plants with semiautomatic control system, and better efficiency were observed at the plants where automatic control systems emplorid and also large industries showed more tendency adopting the automatic plant control system. 2. Overall efficiency of the treatment plants were seen much higher at the first and secand discharge class categories then the lower discharge classes, $80.79\%$ of the plants were see their daily plant operation being controlled by the operator himself. 3. The main causes of the plant stopage and in efficient discharge control were found to be malfunctioning of the plants machineries and equipment or inadequate decision made by the management to save chemicals or electricity. 4. The study showed $60\%$ of the industry treated their wastwater wholly and the rest discharged only with dilution without receiving any further treatment, and this tendency pronounced at the 4th and 5th class discharge category industries. 5. $66.17\%$ of the industry had their storage capacity to accommodate the waste discharge during plants outage while $92.67\%$ of the air pollution discharge industries had no means for the plant outage. 6. $56.77\%$ of the studied industry maintained 24 hour operation of their discharge control systems whill $18.67\%$ of air pollution discharge industries and $10.53\%$ of the waste water discharge industries showed no control effort during the night.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2231-2236
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• 2005

CP (Cellular Phone) is currently one of the most attractive technologies and RT (Robot Technology) is also considered as one of the most promising next generation technology. We present a new technological concept named RCP (Robotic Cellular Phone), which combines RT and CP. RCP consists of 3 sub-modules, $RCP^{Mobility}$, $RCP^{Interaction}$, and $RCP^{Integration}$. $RCP^{Interaction}$ is the main focus of this paper. It is an interactive emotion system which provides CP with multi-emotional signal receiving functionalities. $RCP^{Interaction}$ is linked with communication functions of CP in order to interface between CP and user through a variety of emotional models. It is divided into a tactile, an olfactory and a visual mode. The tactile signal receiving module is designed by patterns and beat frequencies which are made by mechanical-vibration conversion of the musical melody, rhythm and harmony. The olfactory signal receiving module is designed by switching control of perfume-injection nozzles which are able to give the signal receiving to the CP-called user through a special kind of smell according to the CP-calling user. The visual signal receiving module is made by motion control of DC-motored wheel-based system which can inform the CP-called user of the signal receiving through a desired motion according to the CP-calling user. In this paper, a prototype system is developed for multi-emotional signal receiving modes of CP. We describe an overall structure of the system and provide experimental results of the functional modules.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.38-43
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• 2017

Sensor Networks (WSNs) can be defined as a self-configured and infrastructure-less wireless networks to monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants and to cooperatively pass their data through the network to a main location or base-station where the data can be observed and analyzed. Typically a wireless sensor network contains hundreds of thousands of sensor nodes. The sensor nodes can communicate among themselves using radio signals. A wireless sensor node is equipped with sensing and computing devices, radio transceivers and power components. The individual nodes in a wireless sensor network (WSN) are inherently resource constrained: they have limited processing speed, storage capacity, communication bandwidth and limited-battery power. At present time, most of the research on WSNs has concentrated on the design of energy- and computationally efficient algorithms and protocols In order to extend the network life-time, in this paper we are looking into a routing protocol, especially LEACH and LEACH-related protocol. LEACH protocol is a representative routing protocol and improves overall network energy efficiency by allowing all nodes to be selected to the cluster head evenly once in a periodic manner. In LEACH, in case of movement of sensor nodes, there is a problem that the data transmission success rate decreases. In order to overcome LEACH's nodes movements, LEACH-Mobile protocol had proposed. But energy consumption increased because it consumes more energy to recognize which nodes moves and re-transfer data. In this paper we propose the new routing protocol considering nodes' mobility. In order to simulate the proposed protocol, we make a scenario, nodes' movements randomly and compared with the LEACH-Mobile protocol.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.8 s.173
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• pp.143-150
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• 2005

To verify applicability of multi-dimensional spectral analysis (MDSA) fur noise source identification two different approaches which are frequency response and coherent function have been investigated. The coherence function approach appears able to separate the correlated system when the noise sources were coherent. In this study, we identify contribution of structure-borne-noise of vehicle HVAC system using MDSA method. Firstly, to identify the applicability of MDSA method, 4-inputs of vehicle HVAC system were the signals measured by accelerometers attached on the selected noise sources which were composed of blower, evaporator, heater and duct. While 1-output which was driver's position sound was the SPL signals measured by a remote microphone, when the blower motor was operating. We identify efficiency of systems modeled with four Inputs/single output through ordinary coherence function (OCF) and partial coherence function (PCF). As a result of experiment, the blower accounted for $62-88\%$ of the overall level of sound energy density. Also, according to the analysis of acoustic signal and vibration signals measurement, an investigation of the noise source identification in the vehicle HVAC is presented. With the sound intensity method, the major sources of the vehicle HVAC radiation are verified. Also the method of improving the noise reduction is proposed by attaching damping patch access to blower motor and noise reduction is verified.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.1
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• pp.1-15
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• 2008

Recently, because of the various factors by uncertainty of underground, the risks in tunnelling have been occurred increasingly. Therefore, it is very important to estimate and control the risks considering geotechnical conditions for tunnel stability and environmental problems by tunnel construction. In this study, the risk analysis for tunnel stability was carried out by classifying the risk factors such as ground support capacity, ground settlement, the inflow of groundwater into the tunnel and the damage by the earthquake. Also, the risk assessment for the environmental problems was performed by calculating the vibration and noise by blasting and the drawdown of the groundwater level caused by tunnel construction. Each risk factor was evaluated quantitatively based on the probabilistic and statistic technique, then it was analyzed the distribution characteristic along overall tunnel site. Finally, it was evaluated that how much each risk factor influences on the construction cost with a period for tunnel construction, so it is possible to perform reasonable tunnel design which was capable of minimizing the risks in the tunnel construction.