• 한국생산제조학회지
• /
• 제6권4호
• /
• pp.130-137
• /
• 1997

The demand for wire-cut EDM is increasing rapidly in the die and tool making industry. In this study machining characteristics such as machining rate, surface roughness, hand drum form and hardness of machined material are investigated experimentally under the conditions varing pulse on time, pulse off time, peak voltage, wire tension after fixing other conditions in SKD 11 and brass and brass workpiece. It was found that various operating conditions had significant influences on machining characteristics. But the hardness of workpiece was uneffected by operating conditions. Also it was obtained experimentally that brass workpeice had better machinability than SKD 11 one.dition according to the current(Ip) in an electric spark machine : 1) Electrode is utilized Cu and Graphite. 2) Work piece is used the material of carbon steel. The condition of experiment is : 1) Current is varied 0.7(A) to 50(A) and the time of electric discharging to work piece in each time is 30(min) to 60(min). 2) After the upper side of work piece was measured in radius(5$\mu$m) of stylus analyzed the surface roughness to ade the table and graph of Rmax by yielding data. 3) Electro wear ratio is : \circled1Cooper was measured ex-machining and post-machining by the electronic balance. \circled2The ex-machining of graphite measured by it, the post-machining was found the data from volume $\times$specific gravity and analyzed to made its table and graph on ground the data. 4) In order to keep the accuracy of voltage affected to the work piece was equipped with the A.V. R and the memory scope was sticked to the electric spark machine. 5) In order to preserve the precision of current, to get rid of the noise occured by internal resistance of electric spark machine and to force injecting for the discharge fluid , it made the fixed table for a work piece to minimize the work error by means of one's failure during the electric discharging.

• 한국의류학회지
• /
• 제38권1호
• /
• pp.123-135
• /
• 2014

This study classifies types of fashion victims and identifies an internal value system that works for their fashion selection. This study reviewed the definition of 'fashion victim' by tracing similar terms such as fashion terrorist, fashion loser, and worst dresser. We classified fashion styles of fashion victims into four types based on an analysis of articles that pertained to Korean celebrities' fashion and image data. The first type is the fashion style of those who dress without any consideration of body shape. The second type is the style for those who have little consideration in regards to personal image. The third type is the style of those who choose a fashion with excessive decoration. The fourth type is the style for those who use too many fashion items at the same time. Based on a consistent analysis of fashion styles, this study identified the internal value system believed to be working in fashion victims' fashion selection. This study presents three internal value system characteristics. The first is the fetishism that is revealed when fashion victims wear expensive clothes or fashion items that are believed to reveal their personal identity and social status. The second is the blindness which becomes apparent when they follow a fashion in vogue indiscriminately without considering a personal image or body shape. The third is an excessiveness shown when individuals select clothes with too many beads or feathers that are decorative and rich in volume.

• 한국자동차공학회논문집
• /
• 제19권4호
• /
• pp.91-98
• /
• 2011

Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of mounting a quill system to lubricate cylinder parts for smoother operation. In order to apply the common-rail lubricating system to the developed cylinder lubricator as the second research stage, the quill system with a progressively quantitative distributor is improved in the electronically controlled quill system with an accumulating distributor. In this study, the effects of lubricator motor speed, plunger stroke and cylinder back pressure on oil feed rate, maximum discharge and delivery pressures are experimentally investigated by using the electronically controlled quill system with an accumulating distributor in the developed cylinder lubricator. It is found that the oil feed rate of the electronically controlled quill system with an accumulating distributor is larger than that of the quill system with a progressively quantitative distributor because of the increase of delivery speed and volume by changing the location of accumulator in the same experimental condition.

• 한국자동차공학회논문집
• /
• 제20권3호
• /
• pp.26-36
• /
• 2012

Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of mounting a quill system to lubricate cylinder parts for a smooth operation. In order to apply the common-rail lubricating system to the developed cylinder lubricator as the second research stage, the mechanical quill system with a progressively quantitative distributor (M.D.S.) is improved in the electronically controlled quill system with an accumulating distributor (E.D.S.). In this study, the effects of lubricator motor speed, plunger stroke and cylinder back pressure on oil feed rate and inequality rate are experimentally investigated by applying E.D.S. to the developed cylinder lubricator. It is found that the oil feed rate of E.D.S. is higher than that of M.D.S. because of the increase of delivery speed and volume by changing the role of accumulator in the same experimental condition. It can be also shown that, in E.D.S., the inequality rate is decreased a little or hardly unchanged as the cylinder back pressure and plunger stroke is elevated, while the inequality rate increased in M.D.S.. The inequality rates of E.D.S. and M.D.S. are lowered as the lubricator motor speed is increased.

• 대한의생명과학회지
• /
• 제8권3호
• /
• pp.195-202
• /
• 2002

Osteoarthritis (OA), the most common form of arthritis, involves the destabilization of the normal balance between the degradation and the synthesis of articular cartilage and subchondral bone within a joint. As articular cartilage degrades over time, its smooth surface roughens and bone-against-bone contact ensues, producing the inflammation response symptomatic of this 'wear and tear' disease. Although a variety of genetic, developmental, metabolic, and traumatic factors may initiate the development of osteoarthritis, its symptoms (joint pain, stiffness, and curtailed function) typically evolve slowly, and patients experience periods of relative calm alternation with episodes of inflammation and pain. Rheumatoid arthritis (RA), an autoimmune disease of unknown etiology characterized by chronic synovitis and cartilage destruction, affect 1% of the total population. Cartilage is a specialized connective tissue in which the chondrocytes occupy only 5% of the volume. Cartilage is particularly rich in extracellular matrix, with matrix making up 90% of the dry weight of the tissue chondrocytes have cell processes that extend a short distance into the matrix, but do not touch other cells thus in cartilage, cell-matrix interactions are essential for the maintenance of the extracellular matrix. In this study, subtractive hybridization method was utilized to detect genes differentially expressed in chondrocytes treated with methylprednisolone. We have isolated 57 genes that expressed differentially in the chondreocytes by methylprednisolone. 13 clones of them were analyzed with sequencing and their homologies were searched. 8 cDNAS included KIAA 0368, upregulated during skeletal muscle growth 5 (usmg 5), ribosomal protein S 18 (RPS 18), skeletal muscle ryanodine receptor, radial spoke protein 3 (RSP 3), ribosomal protein QM, ribosomal protein L37a (RPL37A), cytochrome coxidase subunit VIII (COX8).

• 열처리공학회지
• /
• 제18권5호
• /
• pp.281-287
• /
• 2005

Titanium aluminium nitride((TiAl)N) film is anticipated as an advanced coating film with wear resistance used for drills, bites etc. and with corrosion resistance at a high temperature. In this study, (TiAl)N thin films were deposited both at room temperature and at elevated substrate temperatures of 573 to 773 K by using a two-facing-targets type DC sputtering system in a mixture Ar and $N_2$ gases. Atomic compositions of the binary Ti-Al alloy target is Al-rich (25Ti-75Al (atm%)). Process parameters such as precursor volume %, substrate temperature and Ar/$N_2$ gas ratio were optimized. The crystallization processes and phase transformations of (TiAl)N thin films were investigated by X-ray diffraction, field-emission scanning electron microscopy. The microhardness of (TiAl)N thin films were measured by a dynamic hardness tester. The films obtained with Ar/$N_2$ gas ratio of 1:3 and at 673 K substrate temperature showed the highest microhardness of $H_v$ 810. The crystallized and phase transformations of (TiAl)N thin films were $Ti_2AlN+AlN{\rightarrow}TiN+AlN$ for Ar/$N_2$ gas ratio of 1:3, $Ti_2AlN+AlN{\rightarrow}TiN+AlN{\rightarrow}Ti_2AlN+TiN+AlN$ for Ar/$N_2$ gas ratio of 1:1 and $TiN+AlN{\rightarrow}Ti_2AlN+TiN+AlN{\rightarrow}Ti_2AlN+AlN{\rightarrow}Ti_2AlN+TiN+AlN$ for Ar/$N_2$ gas ratio of 3:1. The above results are discussed in terms of crystallized phases and microhardness.

• 한국생활과학회지
• /
• 제18권5호
• /
• pp.1093-1101
• /
• 2009

To provide basic data to manufacture superior brassieres, we performed a survey on the wearing and buying habits, and preference of functions and materials of brassieres for 189 women subjects in their twenties. The results of this research are as follows; Style and size are the most important in purchasing brassieres. Flat breasted and sagging breasted subjects were dissatisfied in the fit of the upper cup. 70% of the subjects were ignorant of their brassiere size. Sagging breasted subjects were less satisfied with smoothness, softness, and weight when wearing their bras in comparison with the other types. Conical type breasts were common amongst women in their 20s. They are more likely to wear size 75A and 80A where the full bust girth is 10cm larger than the under-bust. They preferred demi cup brassieres with thin or moderate padding to full cup brassieres with thick padding. On the other hand, 56.8% of subjects wore brassieres all day. The subjects were dissatisfied with the slipping down of the shoulder straps. Large-breasted subjects were concerned more with dampness and the fit on the center front of the brassiere, and brassieres with too thick padding had a poor fit on the center front. Sports-brassieres which fit close to the skin and used stretchable fabric caused more itching and dampness and dissatisfaction in removal of the brassiere.

• 대한기계학회논문집
• /
• 제18권9호
• /
• pp.2374-2385
• /
• 1994

SiCw/Al composite material is especially attractive because of their superior specific strength, specific stiffness, corrosion fatigue resistance, creep resistance, and wear resistance compared with the corresponding wrought Al alloy. In this study, Fatigue crack growth behavior and fatigue crack path morphology(FCPM) of SiC whisker reinforced Al 6061 alloy with 25% SiC volume fraction and Al 6061 allay were performed. Result of the fatigue crack growth test sgiwed that fatigue crack growth rate of SiCw/Al 6061 composite was slower than that of Al 6061 matrix therefore it was confirmed that Sic whisker have a excellent fatigue resistance. And Al 6061 matrix had only FCPM perpendicular to loading direction. On the other hand SiCw/Al 6061 composite had three types in fatigue crack path morphology. First type is that both sides FCPM of artificial notch are perpendicular to loading direction. Second type is that a FCPM in artifical notch has slant angle to loading direction and the other side FCPM is perpendicular to loading direction. Third type is that both sides FCPM of notch have slant angle to loading direction. It was considered that this kinds of phenomena were due to non-uniform distribution of SiC whisker and confirmed by SEM observation for fracture mechanism study.

• 한국의류학회지
• /
• 제39권1호
• /
• pp.55-62
• /
• 2015

This study investigated the thermal insulation of an air-cell pack embedded jacket and down jackets to understand the potential of air-cell pack as a filler for winter outdoor wear. A thermal manikin measured the thermal insulation of the following jackets: HD (heavy down jacket, total weight (Tw) 750g, goose down weight (Dw) 350g), LD (light down jacket, Tw 560g, Dw 140g), AF (air-cell pack embedded jacket, Tw 490g, trunk goose down in LD was replaced to air cell), F (film jacket, Tw 469g, but removed the air in the air-cell pack from the AF), and Control (control jacket, Tw 438g, removed the air-cell pack film from the F). Thermal insulations of each experimental condition were measured in a static standing posture. Total thermal insulations (IT) were 1.29clo (HD), 1.23clo (LD), 1.16clo (AF), 1.20clo (F), and 1.08clo (Control). Body regional thermal insulation was higher in the chest and back than in the abdomen and hip in all conditions. The results suggest that an economical and versatile outdoor jacket with superior thermal insulation will be feasible if the air volume is properly controlled in air-cell pack embedded jackets in consideration of regional different distribution and used in combination with film and down.

• 복식
• /
• 제61권4호
• /
• pp.38-51
• /
• 2011

The purpose of this study is to offer data that designers can utilize substantially, by developing creative materials in knit fashion through the analysis relevant to expression characteristics on the mixture in high low class culture, which were shown in knit fashion of contemporary women, as one of methods of pursuing a plan for being able to be appeared creative and unique knit wear. As for a method of this research, studied concept and characteristics on the mixture in high low class culture by preceding researches. And women's knit fashion was selected that is seen to be 3~18 gauge among the world's 4 collections from 2000~2008. The analysis was made with the analytical frame in mixture pattern, and the analytical frame in design element, and item. The results are as follows. The mixture of kidult element and high fashion was shown with characteristic of expressing humor and fun with graffiti, expression like character and cartoon, and fairy-tale fantasy through the exaggerated trifling article. The mixture of grungy element and high fashion was shown with the expression characteristic in the mixture of heterogenous pattern, and in tear, slit without the end treatment due to fraying the end strand in the knit fashion with basic stitch, patch work, fringing and tone-down gray, use of khaki and blue color, and match in opposite color. The mixture of underwear and high fashion was shown the expression characteristic with the emphasis on underwear line like volume up, or with the mixture of details such as pants in diverse lengths, mini skirt, underwear lace, and ribbon.