• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.140-140
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• 2018

The 3D interconnect technologies have been appeared, as the density of Integrated Circuit (IC) devices increases. Through Silicon Via (TSV) process is an important technology in the 3D interconnect technologies. And the process is used to form a vertically electrical connection through silicon dies. This TSV process has some advantages that short length of interconnection, high interconnection density, low electrical resistance, and low power consumption. Because of these advantages, TSVs could improve the device performance higher. The fabrication process of TSV has several steps such as TSV etching, insulator deposition, seed layer deposition, metallization, planarization, and assembly. Among them, TSV metallization (i.e. TSV filling) was core process in the fabrication process of TSV because TSV metallization determines the performance and reliability of the TSV interconnect. TSVs were commonly filled with metals by using the simple electrochemical deposition method. However, since the aspect ratio of TSVs was become a higher, it was easy to occur voids and copper filling of TSVs became more difficult. Using some additives like an accelerator, suppressor and leveler for the void-free filling of TSVs, deposition rate of bottom could be fast whereas deposition of side walls could be inhibited. The suppressor was adsorbed surface of via easily because of its higher molecular weight than the accelerator. However, for high aspect ratio TSV fillers, the growth of the top of via can be accelerated because the suppressor is replaced by an accelerator. The substitution of the accelerator and the suppressor caused the side wall growth and defect generation. The suppressor was used as Single additive electrodeposition of TSV to overcome the constraints. At the electrochemical deposition of high aspect ratio of TSVs, the suppressor as single additive could effectively suppress the growth of the top surface and the void-free bottom-up filling became possible. Generally, copper was used to fill TSVs since its low resistivity could reduce the RC delay of the interconnection. However, because of the large Coefficients of Thermal Expansion (CTE) mismatch between silicon and copper, stress was induced to the silicon around the TSVs at the annealing process. The Keep Out Zone (KOZ), the stressed area in the silicon, could affect carrier mobility and could cause degradation of the device performance. Cobalt can be used as an alternative material because the CTE of cobalt was lower than that of copper. Therefore, using cobalt could reduce KOZ and improve device performance. In this study, high-aspect ratio TSVs were filled with cobalt using the electrochemical deposition. And the filling performance was enhanced by using the suppressor as single additive. Electrochemical analysis explains the effect of suppressor in the cobalt filling bath and the effect of filling behavior at condition such as current type was investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4763-4768
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• 2014

Recently, aluminum pipes have been used instead of steel pipes for open and shut machines in vinyl housing because of its corrosion-resistance and light weight. In particular, the light weight is very useful for fitting and removal by human resources. On the other hand, an aluminum pipe is weak in winter because aluminum has a larger thermal expansion coefficient than steel. This study examined the freezing and bursting of aluminum pipes by numerical analysis. The mechanical-thermal deformation characteristics were analyzed under the condition of ice volumetric expansion in aluminum pipes reaching 50%. From numerical analysis, large stresses above the yield stress occurred in aluminum pipe after ice expanded in the net diameter immediately. In addition, the freezing and bursting of aluminum pipes was predicted around an ice volumetric expansion of 6 - 7% because the thickness of the aluminum pipe reached an aluminum elongation ratio of 17%. Therefore, it is recommended that aluminum pipes be sealed perfectly to prevent water flow in the pipe. These results suggest that it is very difficult to prevent freezing and bursting of aluminum pipes by water freezing in the pipe.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.5
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• pp.526-546
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• 2001

Fiber-reinforced composite(FRC) was developed as a structural component for dental appliances such as prosthodontic framework. FRC provides the potential for fabrication of a metal-free, excellent esthetic prostheses. It has demonstrated success as a result of its simple fabrication, natural colour, and marginal integrity, and fracture resistance of veneering composite resin and the FRC material. Although it has lots of merits, clinical and objective data are insufficient. The purpose of this study was to evaluate the fracture strength and the marginal fitness of fiber reinforced composite bridge in the posterior region for clinical application. Sixteen bridges of each group. $Targis/Vectris^{(R)}$, $Sculpture-Fibrekor^{(R)}$, and In-Ceram, were fabricated. All specimens were cemented with Panavia 21 to the master dies. Strength evaluation was accomplished by a universal testing machine (Instron). The marginal fitness was measured by using the stereoscope (${\times}50$). The results were as follows. : 1. The fracture strength according to the materials was significantly decreased in order In-Ceram($238.81{\pm}82$), Targis Vectris($176.25{\pm}18.93$), Sculpture-Fibrekor($120.35{\pm}20.08$) bridges. 2. FRC resin bridges were not completely fractured, while In-Ceram bridges were completely fractured in the pontic joint. 3. The marginal accuracy was significantly decreased in order Targis/Vectris ($60.71{\mu}m$), Sculpture-Fibrekor($73.10{\mu}m$) In-ceram Bridge ($83.81{\mu}m$). 4. The fitness of occlusal sites had a lower value than the marginal sites(P<0.001), and the marginal gaps of inner site of the pontic were greater than that of outer sites of the pontic. Fiber reinforced composite bridges are new, esthetic prosthesis and can be clinically used in anterior regions and short span bridges. However, caution must be exercised when extrapolating laboratory data to the clinical situation because there are no long term clinical data regarding the overall success of the FRC.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.6
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• pp.545-559
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• 2002

There has been increasing use of IPS Empress $2^{(R)}$ owing to easy fabrication method, high esthetics similar to natural teeth, good marginal accuracy, and sufficient fracture strength. However, in clinical application, although a luting agent and the tooth cementation bonding procedure influence the marginal accuracy and fracture strength restoration, there has been a controversy in the selection of proper luting agent. This study was to measure the marginal fidelites and fracture strength of IPS Empress crowns according to three cement types, Protec $cem^{(R)}$, Variolink $II^{(R)}$ and Panavia $21^{(R)}$. After construction of 12 experimental dies for each group, IPS Empress $2^{(R)}$ crowns were fabricated and luted the metal master die prepartion of the maxillary right premolar. Marginal gaps before cementation and after cementation were measured. Buccal incline on the functional cusp of specimens were loaded until the catastrophic failure and fracture strength was measured. The results of this study were as follows: 1. The range of gap was $34.04{\pm}4.84{\mu}m$ before cementation and $37.88{\pm}5.00{\mu}m$ after cementation, which showed significant difference by paired t-test (p<0.05). The difference in the results from marginal accuracy according to measuring point proved to be not statistically significant by two-way ANOVA test (p>0.05). 2. The difference in the results from marginal accuracy according to three cement types Proved that The Variolink $II^{(R)}$ cement group had the least gap, $35.43{\pm}5.03{\mu}m$, and showed superior marginal accuracy while there existed statistic significance in Protec $cem^{(R)}$ cement group, $39.06{\pm}4.41{\mu}m$ or Panavia $21^{(R)}$ cement group, $39.16{\pm}4.39{\mu}m$ by two-way ANOVA test & multiple range test (p<0.05). 3. The difference in the results from fractures strength testing according to three cement type groups proved to be statistically significant (p<0.05). The Variolink $II^{(R)}$ cement group shows highest fracture strength of $1257.33{\pm}226.77N$, Panavia $21^{(R)}$ cement group has $1098.08{\pm}138.45N$, and Protec $cem^{(R)}$ cement group represents the lowest fracture strength of $926.75{\pm}115.75N$. 4. Three different cement groups of different components showed acceptable marginal fidelity and fracture strength. It is concluded that IPS Empress $2^{(R)}$ crowns luted using Variolink $II^{(R)}$ cement group had stronger fracture strength and smaller marginal gap than the other cement groups. Although Variolink $II^{(R)}$ resin cement seemed acceptable to clinical applications in IPS Empress $2^{(R)}$ system, the IPS Empress $2^{(R)}$ system still requires long-term research due to the lack of data in clinical applications.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.3
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• pp.243-249
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• 2001

Statement of the problem. The interest in all-ceramic restorations has increased as more techniques have become available. With the introduction of machinable dental ceramics and CAD/CAM systems or Copy-milling systems there is a need for evaluating the quality levels of these new fabrication techniques. Purpose. This study was to evaluate the fitting accuracy of machined all-ceramic crowns made out of an industrially prefabricated feldspathic porcelain. Material and Methods. Three master models with different cutting depth (0.8mm/1.0mm/1.2mm)were produced using a palladium-silver alloy. A total of 36 working dies, 12 of each form, was used for the modellation of prototype resin copings and 36 additional crowns, 12 of each cutting depth, were produced by using the $CEREC^{(R)}2$ system for all crowns. The maginal fit of all 72 crowns was then evaluated on their respective master die at 54 circularly staggered points of measurement per crown under a fixation pressure of 30 N by using a computerized video image system. Results. The medians of the copy-milled $CELAY^{(R)}$ crowns ranged from 29 to $36{\mu}m$. The highest value for the marginal gap was found in group B (cutting depth 1.0mm) at $107{\mu}m$. The median for the $CEREC^{(R)}2$ crowns was found between 43.5 and $70{\mu}m$. The maximum values for all three groups ranged from $181{\mu}m$ to $286{\mu}m$. With $286{\mu}m$ the highest value for marginal gap was found in group C. the Kruskal-Wallis test and multiple comparisons analysis procedure revealed a significant influence of the production technique on the marginal fit in all three groups (p<0,02). Conclusion. 1. The $CELAY^{(R)}$ system is capable to produce all-ceramic crowns with a significantly better marginal fit than the $CEREC^{(R)}2$ system. 2. As far as premolar crowns produced with the $CEREC^{(R)}2$ system are concerned, the cutting depth has a significant influence on fitting accuracy. 3. The production of crowns with an acceptable marginal fit is possible with both systems. However, adhesive luting is recommended for milled feldspathic porcelain crowns.

• Korean Journal of Hospice Care
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• v.5 no.1
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• pp.42-49
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• 2005

To determine which are the culturally specific factors of Korean bereavement, this chapter focuses on the view of death and the traditional mourning process which reflect Korean values and norms. The formation of the Korean view and understanding of death has been strongly influenced by three of its major traditional religions: Shamanism, Buddhism, and Confucianism (Park:1994: Hao:1999) and Christianity more recently. Each religion has a different view of death and the appropriate expression of mourning. Korea accommodates funeral customs and rules strictly as a cultural system and has retained these traditions over a long period; hence, some of the traditional funeral rituals still remain in modern Korean life, although some of the rites have been simplified. We have looked at the various ways in which grief and mourning is displayed and shared in a collective manner over a long period of time. This fits in well within the other Eastern cultures that are collectively organized, and contrary to the Eurocentric models do not hastily seek to detach the living from the dead and recognize that grief is a long process, and different individuals may take different amounts of time to recover from the grief. The view of death and bereavement in Korea has sprung from the roots of three Korean religions, together with the recent addition of Christianity, although they mainly result from the three earlier religions. The beliefs of these religions are still closely linked together in the rituals of Korean bereavement on both conscious and unconscious levels. The influence of these religions is evident in practice through the bereaved family's mourning reactions, funeral rites and customs and its views about death. Korea used to have a period of mourning for three years, following traditional mourning rites; then the chief mourner and the bereaved families could return to their normal life. In spite of this long mourning process for the bereaved family, once the funeral ceremony is finished, people expect the bereaved family not to express their grief in public; even the bereaved family does not like to talk about death. The process for bereaved people is related to mourning processes in terms of detachment from the deceased in order to start a new life. Relatives and the community recommend the performance of the kut ceremony for relieving the grief of the bereaved. When one family member dies in an unlucky way, the bereaved family may have some fear or other psychological reactions of grief such as pain, depression, insomnia and nightmares, hallucinations or other physical reactions. Unlucky deaths give the bereaved a very painful time and these types of reactions are often more serious than reactions to natural death. But through the kut ceremony, the bereaved family can start to make a new relationship with the deceased. The taboo of this type of death and death generally remains a crucial aspect of the isolation that bereaved people might face and the collective nature of mourning(even where it is still present) is unable to address this aspect of the privatization of grief.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7729-7735
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• 2015

As plastic injection mold parts is suitable system mass production making mold. So thick steering wheel parts is desirable to carry out gas injection molding. Gas injection mold is skill to inject nitrogen gas postfilling melting raw material into mold. Gas injection mold have many advantage like retrenchment of material cost, upgrading the guality. etc. It was decided gate position to minimize warpage of parts analysis injection mold process using mold flow software and incase doing gas injection mold using normal p.p material. it occur big warpage. so it is object minimizing warpage of injection parts to change p.p material containing mineral 18% and removing fingering phenomenon trouble as changing gate position. Also in case carrying out gas injection mold, I did comparison and analysis to grasp shape flow in gas setting a standard gate after flowing in raw material. Through this study, I found out changing of thickness by parts shape and it can occur warpage of parts by plastic material even though it carry out gas injection mold and it had a direct influence on trouble of parts by gate position.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.566-571
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• 2012

Marginal and internal fit are very important factor for the clinical long-term success of fixed dental prostheses (FDPs). A variety of methods have been applied to the measuring marginal and internal fit of FDPs. The purpose of this study was to compare the marginal and internal fit of 2 different measuring methods silicone replica technique [SRT] and die cutting technique (DCT). SRT, the space between die and FDPs were filled with light-body silicone, then stabilized by medium-body silicone. DCT, the FDPs were cemented on definitive dies and embedded into epoxy. The silicone replicas and epoxies were sectioned mesio-distal and measured 4 locations (margin, rounded chamfer, axial, occlusal) and using a digital microscope at a magnification $\times$160. For the SRT the mean${\pm}$SDs fit (${\mu}m$) recorded were: margin $88.7{\pm}22.2$, rounded chamfer $90.6{\pm}25.0$, axial wall $61.5{\pm}21.8$, occlusal $134.9{\pm}30.8$. For the DCT the mean${\pm}$SDs fit (${\mu}m$) recorded were: margin $85.3{\pm}18.0$, rounded chamfer $85.4{\pm}24.7$, axial wall $62.0{\pm}21.3$, occlusal $131.7{\pm}30.5$. The mean${\pm}$SDs size (${\mu}m$) of SRT margin was $88.7{\pm}22.2$ and of DCT margin was $85.3{\pm}18.0$. There were no statistically significant difference (p<0.05) of the four parts between SRT and DCT. It is considered an appropriate case to use SRT at fit of FDPs.

• Journal of Korean Philosophical Society
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• v.147
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• pp.215-237
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• 2018

The purpose of this study is to illuminate the precise nature and the central line of Kant's proof of the causal principle stated in the Second Analogy of the 2nd. edition of the Critique of Pure Reason. The study argues for the following thesis: 1. The proof of the Second Analogy concerns only the causal principle called the "every-event-some-cause" principle, and not the causal law(s) called the "same-cause-same-event" principle. 2. The goal of the proof is to establish the possibility of knowledge of an temporal order of successive states of an object. 3. The proof is broadly an single transcendental argument in two steps. The 1st. step is an analytic argument that infers from the given perceptions of an oder of successive states of an objects to the conclusion that the causal principle is the necessary condition for the objectivity of dies perceived order. The 2nd. step is a synthetic argument that infers from the formal nature of time to the conclusion that the causal principle is a necessary condition for die possibility of objective alterations and of empirical knowledge of these alterations. 4. The poof involves not the 'non sequitur' assumed by P. F. Strawson, that is, Kant infers not directly from a feature of our perceptions to a conclusion regarding the causal relations of distinct states of affairs that supposedly correspond to these perceptions.

• Journal of Korean Philosophical Society
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• v.116
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• pp.281-312
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• 2010

Der vorliegende Beitrag problematisiert die Zeichen einer Zeit, in der nach der 'Wende des Sprachparadigmas' alle Prozesse einer Posttranszendenz, die in der heutigen philosophischen Problemsituation versucht werden, $bel{\ddot{a}}chelt$ werden, der Relativismus, Partikularismus und Skeptizismus $verst{\ddot{a}}rkt$ wird, und als Resultat die Kritik, Ablehnung und das Desinteresse an der Ideologie der Vernunft und Wahrheit sich verbreitet. Ich werde daher umgekehrt gerade an diesem Punkt ansetzen und ${\ddot{u}}ber$ die Notwendigkeit und Dringlichkeit der Rehabilitierung der "$Realit{\ddot{a}}t$ einer moralischen Vernunft" nachdenken. Zweck dieses Beitrags ist es, in Zusammenhang mit der Rehabilitierung der $Realit{\ddot{a}}t$ einer moralischen Vernunft, aufzuzeigen, welche theoretische Erkenntnis bzw.moralische Erkenntnis wahr ist, d.h., dass ein 'bewiesenes', da 'objektiv gerechtfertigtes' Argument existiert. $Daf{\ddot{u}}r$ werde ich als erstes auf das Problem der Relativistischen und Skeptizistischen Anhaltspunkte philosophisch eingehen(2), zur ${\ddot{U}}berwindung$ dieser Anhaltspunkte eine Rechtfertigung der rationelen und moralischen $Begr{\ddot{u}}ndung$ versuchen(3). In Folge soll betrachtet werden, dass die Rechtfertigung der rational moralischen $Begr{\ddot{u}}ndung$ mit dem Problem der $Letztbegr{\ddot{u}}ndung$ in enger Verbindung steht(4), und nachdem darauf hingewiesen wird, dass dies durch eine Konfrontation mit der Fallibilismus These zu erkenntnistheoretisch objektiver $G{\ddot{u}}ltigkeit$ gelangt(5), werde ich den Beitrag $abschlie{\ss}en$(6).