• Journal of the Microelectronics and Packaging Society
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• v.17 no.3
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• pp.79-84
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• 2010

Formation of TSV (Through-Si-Via) with an Au seed layer and Cu filling to the via, simplification of bumping process for three dimensional stacking of Si dice were investigated. In order to produce the via holes, the Si wafer was etched by a DRIE (Deep Reactive Ion Etching) process using $SF_6$ and $C_4F_8$ plasmas alternately. The vias were 40 ${\mu}m$ in diameter, 80 ${\mu}m$ in depth, and were produced by etching for 1.92 ks. On the via side wall, a dielectric layer of $SiO_2$ was formed by thermal oxidation, and an adhesion layer of Ti, and a seed layer of Au were applied by sputtering. Electroplating with pulsed DC was applied to fill the via holes with Cu. The plating condition was at a forward pulse current density of 1000 mA/$dm^2$ for 5 s and a reverse pulse current density of 190 mA/$dm^2$ for 25 s. By using these parameters, sound Cu filling was obtained in the vias with a total plating time of 57.6 ks. Sn bumping was performed on the Cu plugs without lithography process. The bumps were produced on the Si die successfully by the simplified process without serious defect.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.4
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• pp.302-309
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• 2017

If a hydrogen explosion occurs in a containment building, its multiplex defense wall may be destroyed and a large amount of radioactive material may be released. The hydrogen occurred interacting with melting fuel rods must be effectively controlled and removed. however, the countermeasures for reducing explosion risk are difficult to carry out, due owing to the various variety of accident scenarios causes and the irregularity of hydrogen distribution and behavior. In this study, We examine the guide structures while considering the ambient flows, in order to improve the efficiency of PAR the widely used Passive Autocatalytic Recombiner(PAR). We simulate the fluid behavior and the hydrogen reduction rate were simulated when a guide is attached to the two-step catalyst PAR. For an upward flow, the consisting of a height of 150mm, a gap of 0mm, and a performs $60^{\circ}$ showed the best. In contrast, for a sideways flow, a consisting of the height of 150mm, a gap of 100mm, and a performs $60^{\circ}$ showed the best in the case of side ward flow. for a downward flow, a consisting of the height of 50mm and a directly attached guide produce the best in the case of down ward flow results.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.4
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• pp.337-346
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• 2014

This study aimed to understand the mode characteristics of a droplet subject to periodic forced vibration and the detachment of a droplet placed on a plate surface. An surface was coated with Teflon to clearly observe the behavior of a droplet. The contact angle between the droplet and surface and the hysteresis were found to be approximately $115^{\circ}C$ and within $25^{\circ}C$, respectively. The coating process was performed in a clean room that had an environment with a low level of contaminants and impurities such as air dust, detergents, and particles. To predict the resonance frequency of a droplet, theoretical and experimental approaches were applied. Two high-speed cameras were configured to acquire side and top views and thus capture different characteristics of a droplet: the mode shape, the detachment, the separated secondary droplet, and the waggling motion. A comparison of the theoretical and experimental results shows no more than 18 discrepancies when predicting the resonance frequency. These differences seem to be caused by contact line friction, nonlinear wall adhesion, and the uncertainty of the experiment. For lower energy inputs, the contact line of the droplet was pinned and the oscillation pattern was axisymmetric. However, the contact line of the droplet was de-pinned as the oscillation became more vigorous with increased energy input. The size of each lobe at the resonance frequency is somewhat larger than that at the neighboring frequency. A droplet in mode 2, one of the primary mode frequencies, exhibits vertical periodic movement as well as detachment and secondary ejection from the main droplet.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.514-519
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• 2000

In order to develop the method for the calculation of flow resistance acting on cage net, the relation between the velocity reduction factor and $S_n/S$, the ratio of total area of netting projected to the perpendicular to the water flow $S_n$ to wall area of netting S, was derived based on the numerical and experimental analysis of the wake flow through a netting twine simplified by a cylinder and a netting panel. The velocity was reduced in accordance with the velocity reduction factor when the flow passed the netting panel upstream of a cage net. The proposed method for the calculation of fluid force acting on a square cage net was based upon the assumption that it could be divided into four side panels and one bottom panel. It was proved that the force could be calculated by the sum of the drag forces acting on the individual netting panels.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.2
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• pp.29-39
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• 1989

Ossifying fibroma is a relatively slow growing tumor, and likely to have presented for some years before its clinical diognosis. The usually well circumscribed nature of ossifying fibroma in jaws lends itself to relative ease of excision and hence the favorable therapeutic results. On occasion, however, particulary in juvenile patient, if maxilla the tumor assumes an aggressive behavior. In that case, because the tumor grows invasively, resection with a margin of healthy tissue is indicated. The case presented is 34 - year old female. The patient had noticed a gradual swelling of the right side of the face approximately 2 months in duration correlation with a intermittent pain on the right maxillary molar area. Palpation disclosed firm swelling on the right anterior and lateral walls of the maxillary sinus extended to the maxillary tuberosity area. The radiographic examination revealed soft tissue mass with multiple dense round calcifications with destruction of anterior and posterolateral wall of the right maxillary sinus and right alveolar process, and hard palate. The mass totally obliterated maxillary sinus and extended to the pterygopalatine fossa. The histologic diagnosis from the biopsied specimen revealed ossifying fibroma. The tumor mass was resected by subtotal maxillectomy procedure due to a recent rapid infiltrative growth. In 5 months of postoperative follow - up period, the patient has favorable prognosis.

• The Korean Journal of Physiology
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• v.4 no.1
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• pp.59-67
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• 1970

In recent observations on vestibular eye movements in mammals, reported by several different workers, it was indicated that the pattern of reflex eye movement from semicircular canal nerve stimulation in rabbits was different from that observed in the other species such as cats and dogs. Observing the different anatomical features of the extraocular muscles of rabbits, Kim ascribed the different pattern of eye movement of rabbits to the functional difference of inferior and superior oblique muscles from those of other species. Present experiment was carried out to elucidate a physiological mechanism underlying in such particular pattern of reflex eye movement in rabbits. An individual canal nerve was selectively stimulated, under a dissecting microscope, by a fine electrode induced into an ampulla through a hole provided on the wall of corresponding osseous canal, and responses of the extraocular muscles were checked by recording the isotonic changes of muscle length. Following results were obtained. 1. Direct stimulation of the superior or inferior oblique muscles Produced upward or downward movement of the eye turning toward medial side respectively. 2. Stimulation of the unilateral canal nerve Produced a marked contraction of a main contracting ocular muscle and simultaneous relaxation of an antagonistic muscle in both eyes. Less potent contraction of an additional ocular muscle was observed and it appeared to augment the function of the main contracting muscle in the ipsilateral eye. 3. Stimulation of superior semicircular canal nerve caused a primary contraction of superior rectus, synergic contraction of superior oblique and relaxation of inferior rectus in ipsilateral eye. Contraction of inferior oblique and relaxation of superior oblique were observed in the contralateral eye. 4. Stimulation of lateral semicircular canal nerve produced a primary contraction of medial rectus, synergic contraction of superior oblique and relaxation of lateral rectus in the ipsilateral eye. Contraction of lateral rectus and relaxation of medial rectus were observed in the contralateral eye. 5. Stimulation of inferior semicircular canal nerve produced a primary contraction of superior oblique, synergic contraction of superior rectus and relaxation of inferior oblique in the ipsilateral eye. Contraction of. inferior rectus and relaxation of superior rectus were observed in the contralateral eye. 6. Upon stimulation of individual canal nerve, the pattern of eye movement in rabbits is different from those of cats, however, the responses of the extraocular muscles appear to be similar in two species. Therefore, it is concluded that the different Pattern of eye movement in both species are not due to the possible difference of vestibule-ocular reflex pathways but to the functional difference of superior and inferior oblique muslces.

• Research in Plant Disease
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• v.23 no.2
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• pp.114-149
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• 2017

World-wide crop loss caused by insect pest and nematode reaches critical level. In Korea, similar crop loss has been gradually augmented in the field and greenhouse due to continuous crop rotation. The current methods on controlling herbivorous insects and plant parasitic nematodes are mostly depended on agro-chemicals that have resulted additional side-effect including occurrence of resistant insects and nematodes, environmental contamination, and accumulation in human body. To overcome the pitfalls, microbe-based control method have been introduced and applied for several decades. Here, we revised biological control using by the bacteria, fungi, and virus in order to kill insect and nematode and to attenuate its virulence mechanism. The introduced microbes mainly secreted out the hydrolysing enzymes and toxic compounds to target host membrane or cell wall directly. Indirectly, the microbe-triggered plant innate immunity against insects and nematodes was also reported. In conclusion, we provide a new frontier of microbe-based environmentally friendly procedure and effective methods to manage insects and nematodes.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.202-210
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• 2005

In this study, the fly ash was employed as a possible alternative to the bentonite for its high sorption capacity against cationic heavy metal. To consider the constituents of barrier possibly used, the specimens were mixed with different material contents (fly ash : weathered soil : bentonite), then sorption test was performed. Also the specimens were molded on the wet side of optimum moisture contents like mixing ratio of sorption test and their hydraulic conductivities were measured in flexible-wall permeameters. And to confirm the effect of dissolved cations, the hydraulic conductivity tests were repeated by converting the permeant liquids from water to $Cd^{2+}$ solution. Finally, the Cd-concentration at the effluent was analyzed for 500hrs to compare the effectiveness of each specimen in contaminant retardation. Test results showed that the more the ratio of fly ash increase, the more Kd value increase, and the hydraulic conductivity of weathered soil/bentonite (95:5) mixture was the lowest $(2.9*10^{-8}cm/sec)$, and specimens made of fly ash and fly ash/weathered soil mixtures showed similar hydraulic conductivity. Although the permeant liquid was changed from water to $Cd^{2+}$ solution, the hydraulic conductivity of all specimens except for weathered soil maintained similarly like before. Consequently, the initial breakthrough point of Cd in weathered soil specimen was observed at about 5hrs after the test started while that of fly ash specimens was not observed during the whole test period of 500hrs. The results implied that fly ash had a sufficient retardation capacity against contaminant transport possibly by its high sorption capacity although it showed little effect on the reduction of hydraulic conductivity. Based on the test results, it could be concluded that the fly ash can be possibly used as a suitable barrier material in containment system to attenuate the contaminant transport for its high retardation capacity and for the low cost.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.6
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• pp.689-694
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• 2014

We report a female small cell lung cancer patient in the extensive stage(T3N3Mx). After 6 cycles of chemotherapy combined radiation therapy, she received inpatient Korean medical care including herbal medicine, acupuncture therapy and concurrent western oral medications of opioid analgesics and anti-anxiety agent. The chief complaint was right side thoracic wall pain which had started after chemotherapy and was not effectively controlled by analgesics. For this condition, we treated her with 2Hz of constant electrical stimulation on Jiaji (Ex-B2) points T5-T7 laterally (right) using three needles for 20 minutes once a day for 9 days. With every session of electrical acupuncture treatment, thoracic pain decreased acutely. Korean medicine treatments including Jiaji (Ex-B2) point stimulation might be tried for lung cancer patients with uncontrolled thoracic pain at least for the acute analgesic effect.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.107-115
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• 2011

In this study, the vibration analysis of the underground box structures induced train movement is studied. In order to perform these analysis, dynamic data, which was measured when subway is in service, are gained by attaching accelerometers on the structure such as lower beam, lateral wall and upper slab. Also, accelerometers are attached on the lower beams and side walls of the gravel ballast and concrete ballast sections in order to compare vibration due to ballast materials. The vibration results of upper slabs and lower beams reveal that the vibration on the upper slabs is greater than the lower beams. Also, the results of the crack gauge on the upper slab show that crack width dose not change due to vibration, These means that the effect of the vibration on the structure is very limited. In order to evaluate the vibration of the structure, acceleration unit is converted to velocity unit comparing with the existing velocity data gained from the platforms.