• Tribology and Lubricants
• /
• v.22 no.4
• /
• pp.225-229
• /
• 2006

The issue with the drainpipe now a day is that they are laid underground. Causing us to perform additional work to repair, such as digging up the ground and peeling off the insulator that surrounds the pipe. And such series works are difficult that concession appears from government and municipal office. However, if we can save time and money. Performance of piping robot that we are studied in existing session through fixing unit and improvement of cutting bit shorten and wished to heighten work efficiency. And we are trying to develop a unit that can cut up the projecting parts which connects with the interior part of the drainpipes.

• Journal of Power System Engineering
• /
• v.6 no.1
• /
• pp.82-87
• /
• 2002

Not only ferrous but also non-ferrous materials such as aluminum, brass, plastic and woods need cutting operation in recent manufacturing industry. Over the past few years a considerable number of studies have been made on non-ferrous metal cutting. But more study is required to meet various engineering needs. The purpose of this paper is to preform an experiment on the influence of feed-rate adjustment and side rake angle in turning operations from non-ferrous metals. As a result, the surface roughness was reduced when a side-rake angle increases and feed-rate decreases in the case of the plastic, brass, aluminum, and paulownia. Therefore, this papers develop a new type bite that be used to adjust side-rake angle.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.11 no.9
• /
• pp.833-836
• /
• 2001

One of the most important technology in Factory Automation and Unmanned Automation is to construct the diagnostic system for manufacturing process. To improve the productivity in cutting process, the state of tools such as bite, drill, endmill should be monitored continuously. In this study, fuzzy logic was used to check the wear of drill in drilling process. The input variables to construct the fuzzy rules are cutting force and the rate of cutting force's change. The experiment was done with the fixed spindle speed and feed rate in cutting condition. The proposed algorithm is verified by comparing Fuzzy wear with real wear measured.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.16 no.2
• /
• pp.133-147
• /
• 2000

A well-planned, precise occlusal adjustment of natural teeth has some distinct advantages over other forms of occlusal therapy. It should be emphasized, however, that an occlusal adjustment is an irreversible procedure and has definite contraindications in some mouths. Generally, the treatment methods for the patients that has open-bite will be following as below. : (1) Use of removable orthopedic repositioning appliance, (2) Orthodontics, (3) Full or partial reconstruction of the dentition, (4) Orthognathic surgical procedure, (5) Occlusal adjustment of the existing natural teeth, (6) Any combination of the above. Above all, the advantages of occlusal adjustment of natural teeth are : (1) the patient is more able to adapt to the changes in jaw position and posture; (2) the phonetic or speaking ability of the patient is not significantly changed and usually is improved; (3) the esthetics of the natural teeth is not altered and often is better; (4) the hygiene of the individual teeth is easily maintained; and (5) the functional usage of the teeth as cutting and chewing devices is markedly improved. The objective of an occlusal adjustment, as with any form of occlusal therapy, is to correct or remove the occlusal interferences, or premature contacts, on the occluding parts of the teeth which prevent a centric relation closure of the mandible. A systematic, disciplined approach can be followed in treatment, the objectives should be listed. They are : (1) Centric relation occlusion of the posterior teeth. (2) Proper "coupling" of the anterior teeth. (3) An acceptable disclusive angle of the anterior teeth in harmony with the condylar movement patterns. (4) Stability of the corrected occlusion. (5) Resolution of the related symptoms. For the patient with open-bite on anterior and posterior teeth, this case report shows the treatment methods in combination the fixed prosthesis with the selective cutting of the natural teeth. Occlusal adjustment is no longer an elective procedure but a mandatory one for patients requiring restorations and those in treatment for TMD dysfunctions or those whose dentitions show signs of occlusal trauma. Occlusal adjustment is essential for all who do not display the above lists.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.10a
• /
• pp.1025-1028
• /
• 2002

In this paper, a micro-turning lathe is introduced for micro machining of aluminum rod. To give feed motion, stepwise motion[2] actuators are used instead of the conventional inchworm mechanism. These are consisted of two Piezoelectric ceramics; one is for feeding the slider, and the other is for clamping the slider in the guide way of the body. The guide is V-form. The linearity and positional accuracy of the actuators is good enough far high precision motion. Since the system is more compact than the conventional system using three Piezoelectric ceramics, it is applicable for the micro-machine or MEMS unit. To fabricate the lathe, a small spindle unit with ball bearings of diameter of 10 millimeter is built-up on the top the slider. The motion is feed backed with miniaturized linear encoder attached each axis slider. The diamond tool bite is used for cutting tool. The machining is tried to make small diameter rod. The possible diameter that can be machined in this machine is presented as well as chip formation, surface roughness, and machinability.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.21 no.2
• /
• pp.191-195
• /
• 2012

Heavy flint optical glass(SF57HHT) is new material that has extremely high transmittance. Due to brittleness and high hardness, optical glass is one of the most difficult to materials for ultra-precision turning. According to the hypothesis of ductile machining, all materials, regardless of their hardness and brittleness, will undergo transition from brittle to ductile machining region below critical undefromed chip thickness. In this study, cutting test was carried out to evaluate cutting performance of heavy flint glass using ultra-precision machine with single crystal diamond bite. The machined workpiece surface topography, tool wear and surface roughness were examined using AFM and SEM. The experimental results indicate that the machining mode become the brittle mode to ductile mode, when the maximum undeformed chip thinkness is large than critical value. Tool wear mainly occurs on the flank face and its wear mechanism is dominated by abrasion. This study demonstrates the feasibility of SF57HHT by diamond turning.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.16 no.3
• /
• pp.184-191
• /
• 1996

The purpose of this paper is to investigate components of surface roughness in turning with respect to the tool configuration and the changes of working conditions. Tool configurations of SNMG120404, SNMG120408 and DNMG150404, DNMG150408 are used, and working conditions such as cutting speed 3nd feed are varied. That is, the changes of cutting speed and feed were 150, 200, 250 m/min and 0.05, 0.1, 0.3 mm/rev, respectively. From the results obtained by the frequency analysis with spectrum, it is noted that the surface roughness was influenced most significantly by the feed. It is also observed that the vibration of bite had an effect on both the surface roughness and the surface waviness. Moreover, the influence of surface roughness increases as the feed decreases. Lastly, the vibration of the spindle was found to have little influence on the surface roughness in normal cases and the tool configuration was not the components of the surface roughness.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.45 no.2
• /
• pp.77-84
• /
• 2009

This paper is to investigate the effect of the immersion time in the traditional hairtail hand line for developing the fishing methods and the fishing gear in the coast of jeju. The operating of 32 times was made with each different immersion time of hairtail hand line, and the relations between the catch and the immersion time were examined. As the result, targeted species rate was over 98% of total catch. From about 800 seconds after casting, the hooking rate was decreased and the bite loss rate was increased, it seems to be made by the decreasing factors of predators including the cutting of branch lines etc. In addition, it was supposed that the hooking rate and the bait loss rate had a deep connection with feeding time zone. The level of the correlation coefficient of the bait loss rate according to the immersion time was 0.54 at $p{\leq}0.01$, in the case of the hooking rate, 0.59 was chosen after about 800 seconds. The hooking rate and the bait loss rate according to the hook number were not irrelevant to the fish school layer. Additionally, it was assumed that the bait loss rate was related to the depth of water.

• Journal of the Korean Society of Food Culture
• /
• v.29 no.2
• /
• pp.163-177
• /
• 2014

This study aimed to investigate the perception, consumption, and acceptability of convenience mealsin low-income female elderly attending a lunch program at a community well fare center. Using in-depth interviews, qualitative data were collected 11 elderly females ($62.5{\pm}11.2y$) living in Seoul. Participants tried to eat various foods in small-portionsat home, although they ate out what they were offered. Elderly females preferred lunch box-type meals containing a bowl of rice served with toppings, gruel, or Bibimbop due to the growing unavailability of cooking or preparing a meal. Side-dish type convenience mealswere also preferred among elderly females since boiled rice can be easily prepared according to individual preferences. In addition, participants preferred healthy foods. Convenience meal planning and production, appropriate kinds of foods, cooking methods, menus, and packaging should be selected based on the elderly's functional atrophy in chewing, swallowing, digestion, and metabolic diseases. Furthermore, food preferences and comfort foods among the elderlyneed to be identified and characterized. Therefore, more information, including bite size, cutting size, and food texture, should be provided to understand and develop convenience meals for the elderly.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.3
• /
• pp.1645-1651
• /
• 2015

This paper describes the changes of shape accuracy in workpiece materials depending on the turning clearance angle. The experiments started from choosing three workpiece materials, SM45C(machine structural carbon steel), STS303(stainless steel) and SCM415 (chrome-molybdenum steel). The experiments showed specifically how features of selected materials changed when they were processed with diverse machining depths, 0.1 mm, 0.2 mm and 0.3 mm, with various negative angles, $0.0^{\circ}(-6.0^{\circ})$, $0.3^{\circ}(-6.3^{\circ})$ and $0.9^{\circ}(-6.9^{\circ})$, and called cutting edge inclination starting from a fixed rotational speed, 2,500 rpm, focusing on the feed rate, 0.07 mm/rev and 0.10 mm/rev. The results of the accuracy of processing, cylindricity, deviation from coaxiality, etc. were compared using the graph and table. The accuracy of cylindricity in the order of degree $0.0^{\circ}{\rightarrow}0.3^{\circ}{\rightarrow}0.9^{\circ}$ depending on the workpiece materials showed the best cylindricity when it was $0.9^{\circ}$. In conclusion, the accuracy improved in specific degrees irrespective of the quality of the materials when the bite negative angles increased. This means that workability improved in these experiments. In addition, the processing shape changed depending on depth of the cut and feed rate.