• Journal of the Korean Society for Precision Engineering
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• v.18 no.3
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• pp.107-114
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• 2001

The durability of head/disk interface is an important issue for hard disk drives. Currently, there are several means of assessing the performance and integrity of the head/disk interface. In this work Track Average Amplitude(TAA) signal was used to analyzed the head/disk interface with respect to variations in disk velocity, slider pre-load and preformed scratch on the disk. Particularly, TAA variation due to disk defect in the form of a scratch was investigated.

• Tribology and Lubricants
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• v.15 no.1
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• pp.52-58
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• 1999

Nano-indentation and nano-scratch tests were peformed to assess the mechanical and tribological properties of the coating on a commercially available thin-film magnetic recording disk. Surface topography and roughness of the disk was studied using atomic force microscopy. The hardness and elastic modulus data show a peak at an indentation depth equivalent to the thickness of carbon overcoat, indicating strong influence of the coatin $g_strate interaction and the coating surface roughness on the measurements. The variations of surface roughness data were analysed statistically based on the normal probability distribution theories and Weibull cumulative probability theories.es.

• Journal of the Korean Society of Costume
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• v.15
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• pp.47-54
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• 1990

Kyu-Soo Park wrote the book "Gur Ga Jap Bok Ko" (Proposition for Household Casuals) around A.D. 1865. He was a widely-learned man and a proponent of Korean self-consciou-seness like his fellow Pragmafist against then prevailing Chinese influence, which had already penetrated deeply into ordinary life style. According to this fact we can see not only the general dress-cystoms but the new customs of some high-birth People with evident self-consciouseness like him at that time. For example, they wore "Sim Eui" and "Bok Gun" as the dress of their ordinary life in spite of the general dress custom wearing the "Do Po" (Traditional Korean full-dress attire) and "Gat" (Traditional cylindrical Korean hat) as an ordinary or a ceremonial dress irrespective of rank at that time. Women wore an overcoat with "Chima" and "Jur. Go Ri" instead of the shortened "Jur, Go Ri" and buttock exagerating "Chima" largely popular at that time too. And also wore "So Eui" instead of "won Sam" or "Dang Eui" prevailing for the psychological resemblance of higher ranking group. Male yougnsters wore "Sa Gyu Sam" as an ordinary life dress and Girls wore "Chima and Jur Go Ri".

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.3
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• pp.79-86
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• 1992

The cause of excess current noise which appears some times in RuO$_2$ thick film chip resistors and the process to reduce such noise are investigated. We observed that too large thermal expansion coefficients of resistor paste and electrode metal paste can induce the mechanical stress and microcracks in the contact region of the two sintered materials. Such microcracks result in the reduction of conduction paths in the sintered electrode and this provokes the increase of the resistance value and the current noise. Such excessive current noise induced by microcracks could be reduced or even eliminated by using an enlarged overcoat patterns in the plating process or by adding an additional annealing process before plating.

• Tribology and Lubricants
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• v.17 no.4
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• pp.312-320
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• 2001

In magnetic hard disk drives, higher areal recording density requires reduction of head-disk spacing. To overcome the increase of stiction associated with reduction of head-disk spacing, a padder slider, which adds pads to slider's air bearing surface, can be one of the practical solution for sub 20 nm flying height, and even for near contact recording. This study investigated the tribological characteristics of a padder slider. A padder slider took off slowly but showed less friction force than a normal slider. The hot/dry CSS test and drag test indicated that pad wear of a padder slider was negligible. The tribological performance of disk is an important factor to be considered. In particular, less carbon overcoat layer of the disk will result in higher stiction and wear in slider/disk interface. In conclusion, a padder slider shows encouraging tribological performances for practical use in HDD.

• Korean Journal of Materials Research
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• v.3 no.1
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• pp.12-18
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• 1993

Abstract The effect of the film stress on the thermal stability of TiSi, films under the dielectric overcoat was investigated. TiS$i_2$ films with the sheet resistance of 1.2 ohm/sq. were produced by a solid-state reaction between sputtered Ti film and single-crystalline Si in an RTA (rapid thermal anneal) machine. Dielectric overcoats such as the USG (Undoped Silicate Glass, Si$O_2$) film and the PE-SiN(S$i_3$$N_4$) film were deposited by AP-CVD and PE-CVD, respectively, on the TiS$i_2$ film. The thermal stability of the TiSi, film was evaluated by changes in the sheet resistance, film stress and microstructure after furnace anneals at 90$0^{\circ}C$. Agglomeration of the TiSi2 film high temperatures results in the increase of sheet resistance and the decrease of tensile stress of TiSi, film. The stress level of the TiSi" PE-SiN and ~SG films at 90$0^{\circ}C$C was 1.3${\times}{10^{9}}$, 1.25 ${\times}{10^{10}}$, 2.26 ${\times}{10^{10}}$ dyne/c$m^2$ in tensile, respectively. Dielectric films deposited by CVD on TiSi, was effective on preventing agglomeration of TiSi,. The PE-SiN film mproved the thermal stability of TiSi, more effectively than the AP-CVD USG film. It is considered that agglomeration of the TiS$i_2$ film under the stress of dielectric overcoat at high temperature can be caused by a diffusional flow of atom called Nabarro-Herring microcreep.reep.

• Conservation Science in Museum
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• v.20
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• pp.61-76
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• 2018

The National Museum of Korea conducted conservation treatmenton the armor in its collection for the purposes of public display and appropriate preservation. This was preceded by a literature study on the types and features of the armor in order to collect basic data for secure and accurate conservation treatment. The literature study found that during the Joseon dynasty, armor was named in reflection of precise details including the color, material, status of the wearer, and even the certain parts of a suit of armor. In general, the name of armor includes the details in the order of color, underlying textile, and scale material (e.g., iron, leather). The former part of the name presents the features of the garment and the latter part refers to the material of the scales or the status of the wearer. The study also found that main materials used in armor include textiles, leather, and metal, and armor can be classified by the materials of the scales-e.g., metal armor (鐵甲), leather armor (皮甲), paper armor (紙甲), paper-and-fabric armor (淹心甲), silk armor (緞甲). Joseon-period armor can also be classified into four types according to its structure and the method of wearing, and overcoat(袍)-style armor was the most widely used in the period following the Japanese Invasion of Joseon (1592-1598) through the late nineteenth~early twentieth century. Overcoat-style armor was commonly worn by infantry, and the four examples of armor with leather scales at the National Museum of Korea belong to this category.

• The Research Journal of the Costume Culture
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• v.6 no.3
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• pp.56-72
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• 1998

Vest is a general term for a sleeveless upper garment and it derives from a kolobus of a sleeveless tunic style that was started to be worn as a substitution of a chiton by the peasantry in Greek period. The kolobus started to be called a colobium or a tunica from Roman period and the former was named for a vest style tunica which was worn by the people of the lower classes in early Roman period. Similarly, a German colobium of North Europe which was worn during the same period was the same kind of clothe as the Roman colobium. The colobium came to be worn over a dalmatica as an outer garment by early Christians when it was the Middle Ages, who succeeded the tradition of colobium as they went through ancient Rome, Creek and Byzantine days. North Germans also succeeded the colobium tradition of ancient Germans as it was and so continued to wear it in tight style. The simple vest style of colobium was getting vanished from the mid of the Middle Agnes and a new style of vest named jupon was started to be worn by soldiers. The jupon was to protect soldiers' bodies from either were cold weather or enemies wearing under armors as it was made with double cotton pad by quilt. From 14th century, the jupon began to be worn by not only soldiers but also the humble of lower classes. All the jupon which were made in quilting and padding of that time began to be named a pourpoint by the humble. When Renaissance in 16th century came, the pourpoint began to be developed to an exaggerating body-line style. The neckline of pourpoint was getting highly influenced by Spain and a peacecod-belly of it emphasized the exaggerated masculine beauty of Renaissance by padding in round. The sleeves were puffed out and the whole purpoint was made to expose an inner chemise by slashing vertically or obliquely. But in 17th century, the pourpoint has been changed into more simple style without padding, puffing out and slashing influenced by the citizens' clothes of Netherlands. The pourpoint came to be more comfortable bulky style with short sleeves or sleeveless and straight side lines. The pourpoint in mid 17th century turned to be a bolero jacket style by gradually being tightened. It had been then changed into a vest style with sleeves and worn under an overcoat with the name of vest in the end of 17th century. The early vest was 2∼3 inches les in length than the overcoat and had long sleeves and many ornamental buttons on front. It was also made as a home wear to be worn it alone at home. In 18th century, the length of the vest became shorter compared with that of 17th century and the most important decorative item in clothes. It again came to have complete sleeveless vest style and had very short length reaching waist in the end of 18th century. When it was in 19th century, the vest had developed into more various style and colors and style had been applied to be worn by individuals with their tastes. Around the end of 19th century, the increasing tendency to be casual by industrialization influenced on clothes in all aspects of life and so the male vest has been gradually changed into more casual style. Nowadays, it has been developing into various uses in modern male clothes to show their characters.

• Journal of KSNVE
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• v.9 no.4
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• pp.643-651
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• 1999

A brief description of the current technology (contact-start-stop) employed in most of today's hard disk drive is presented. The dynamics and head/disk interactions during a start/stop process are very complicated and no one has been able to accurately model the interactions. Thus, the head/disk interface that meets the start/stop durability and stiction requirements are always developed statistically. In arriving at a solution. many sets of statistical tests are run by varying several parameters. such as, the carbon overcoat thickness. lubricant thickness. disk surface roughness, etc. Consequently, the cost associated III developing an interface could be significant since the outcome is difficult to predict. An alternative method known as Load/Unload technology alters the problem set. such that. the start/stop performance can be designed in a predictable manner. Although this techno¬logy offers superior performance and significantly reduces statistical testing time, it also has some potential problems. However. contrary to the CSS technology. most of the problems can be solved by design and not by trial and error. One critical problem is that of head/disk contacts during the loading and unloading processes. These contact can cause disk and slider damage because the contacts are likely to occur at high disk speeds resulting in large friction forces. Use of glass substrate disks also may present problems if not managed correctly. Due to the low thermal conductivity of glass substrates. any head/disk contacts may result in erasure due to frictional heating of the head/disk interface. In spite of these and other potential problems. the advantage with L/UL system is that these events can be understood. analyzed. and solved in a deterministic manner.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.15-16
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• 2010

We used Brewster's Law to examine the mechanism of liquid crystal (LC) alignment on an organic insulation layer when subjected to ion-beam irradiation. Brewster's Law implies that the maximum rate polarized rayon a slanted insulation layers on the substrate and it illustrates the dependence of polarization and themechanical structure on the ion beam irradiation process. The pretilt angle of nematic LCs on the organic insulation surface was about $1.13^{\circ}$ for an ion beam exposure of $45^{\circ}$ for 1 minute at 1800eV. This shows the dependence of LC alignment on the polarization ratio in a slanted organic insulation layer. We also discussed the electro-optical characteristic of twisted nematic (TN) LCD using ion beam irradiation on organic overcoat layer.