• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.42 no.9 s.339
• /
• pp.9-18
• /
• 2005

To make high-performance, low-power transistors beyond the technology node of 60 nm complementary metal-oxide-semiconductor field-effect transistors(C-MOSFETs) possible, the effect of electron mobility of the thickness of strained Si grown on a relaxed SiGe/SiO2/Si was investigated from the viewpoint of mobility enhancement via two approaches. First the parameters for the inter-valley phonon scattering model were optimized. Second, theoretical calculation of the electronic states of the two-fold and four-fold valleys in the strained Si inversion layer were performed, including such characteristics as the energy band diagrams, electron populations, electron concentrations, phonon scattering rate, and phonon-limited electron mobility. The electron mobility in an silicon germanium on insulator(SGOI) n-MOSFET was observed to be about 1.5 to 1.7 times higher than that of a conventional silicon on insulator(SOI) n-MOSFET over the whole range of Si thickness in the SOI structure. This trend was good consistent with our experimental results. In Particular, it was observed that when the strained Si thickness was decreased below 10 nm, the phonon-limited electron mobility in an SGOI n-MOSFT with a Si channel thickness of less than 6 nm differed significantly from that of the conventional SOI n-MOSFET. It can be attributed this difference that some electrons in the strained SGOI n-MOSFET inversion layer tunnelled into the SiGe layer, whereas carrier confinement occurred in the conventional SOI n-MOSFET. In addition, we confirmed that in the Si thickness range of from 10 nm to 3 nm the Phonon-limited electron mobility in an SGOI n-MOSFET was governed by the inter-valley Phonon scattering rate. This result indicates that a fully depleted C-MOSFET with a channel length of less than 15 m should be fabricated on an strained Si SGOI structure in order to obtain a higher drain current.

• Journal of Advanced Marine Engineering and Technology
• /
• v.41 no.4
• /
• pp.337-344
• /
• 2017

The demand of liquified natural gas is increasing due to environmental issues. This reason has resulted in increasing the capacity of liquified natural gas cargo tank. The Mark-III type primary barrier directly contacts liquified natural gas. Also, the primary barrier is under various loading conditions such as weight of liquified natural gas and sloshing loads. During a ship operation, various loads can cause fatigue failure. Therefore, the fatigue life prediction should be evaluated to prevent leakage of liquified natural gas. In the present study, the fatigue analysis of insulation system including primary barrier is performed using a finite element model. The fatigue life of primary barrier is carried out using a numerical study. The value of principle stress and the location of maximum principle stress range are calculated, and the fatigue life is evaluated. In addition, the effects on the insulation panel status and the arrangement of knot or corrugation are analyzed by comparing the fatigue life of various models. The insulation system which has best structural performance of primary barrier was selected to ensure structural integrity in fatigue assessment. These results can be used as a design guideline and a fundamental study for the fatigue assessment of primary barrier.

• Journal of Society of Preventive Korean Medicine
• /
• v.8 no.2
• /
• pp.55-63
• /
• 2004

Objectives : This study was designed to identify the possibility of aroma oils as the complementary medical goods specially for the effects of aromatheraphy on xerosis cutis. Materials and Methods : The participants were 23 adult patients and all participants of this study use aroma oils which is known to effect on xerosis cutis. The subjects consist of voluntary patients with xerosis cutis in Seong-So Hospital in Andong Kyoungbuk, Korea. From April 1st to April 30th, 2004 for 4 weeks, the subjects massaged aroma oils on itching parts or the whole body. Aroma oils were Lavender, Losemary, Jasmine and blended drop by drop per 10ml jojoba oil which used a carrier oil. Skin pH was measured with a skin pH meter(Model : HI98110, Se-Chang instruments, made in Portuga. After 4weeks using aroma oils, the participants answered questions about the feeling of satisfaction with aroma oils. Results : Changes in the physiological indices. The mean deviation of skin pH was $5.58{\pm}0.47$ points before using aroma oils and $5.53{\pm}0.45$ points after 2 weeks, no statistical significance was found(p=0.221). MD was $5.36{\pm}0.41$ points after 4 weeks using aroma oils, which was statistically significant decrease of 0.22 points(p=0.001) Changes on the Pruritus Score Scale. A modified scale of the Pruritus Score Scale(Duo, 1987) was used to measure the severity, location, frequency, and the inconveniences of daily life due to prurius. The maximum scale of severity was 4 points, the full marks of location was 2 points, the full marks of frequency was 3 points, the full marks of inconveniences of daily life due to pruritus was 3 points. The scores ranged from 0 to 12, with 12 indicating the most severe pruritus. There was no statistical difference in severity and frequency score at 4 weeks later(severity p=0.097, frequency p=0.633). A statistically significant difference was found in the score of location and the inconveniences of daily life due to pruritus(each p=0.003). Conclusion : Generally speaking, the patient suffering from renal itch is the higher than normal in skin pH levels. that means to show alkaline condition of skin surface. In some case in this study, skin pH levels was rather lower than normal levels when measured actually patients suffering from renal itch by skin pH meter. But in this study post-test skin pH levels decreased, showing the contribution of aromathrapy to acidic condition of skin surface in suffering from renal itch. It seems to be some help to cure a pruritus and also have no ill effects on aroma oils.

• Korean Journal of Materials Research
• /
• v.23 no.12
• /
• pp.714-721
• /
• 2013

A stoichiometric mixture of evaporating materials for $ZnAl_2Se_4$ single-crystal thin films was prepared in a horizontal electric furnace. These $ZnAl_2Se_4$ polycrystals had a defect chalcopyrite structure, and its lattice constants were $a_0=5.5563{\AA}$ and $c_0=10.8897{\AA}$.To obtain a single-crystal thin film, mixed $ZnAl_2Se_4$ crystal was deposited on the thoroughly etched semi-insulating GaAs(100) substrate by a hot wall epitaxy (HWE) system. The source and the substrate temperatures were $620^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the single-crystal thin film was investigated by using a double crystal X-ray rocking curve and X-ray diffraction ${\omega}-2{\theta}$ scans. The carrier density and mobility of the $ZnAl_2Se_4$ single-crystal thin film were $8.23{\times}10^{16}cm^{-3}$ and $287m^2/vs$ at 293 K, respectively. To identify the band gap energy, the optical absorption spectra of the $ZnAl_2Se_4$ single-crystal thin film was investigated in the temperature region of 10-293 K. The temperature dependence of the direct optical energy gap is well presented by Varshni's relation: $E_g(T)=E_g(0)-({\alpha}T^2/T+{\beta})$. The constants of Varshni's equation had the values of $E_g(0)=3.5269eV$, ${\alpha}=2.03{\times}10^{-3}eV/K$ and ${\beta}=501.9K$ for the $ZnAl_2Se_4$ single-crystal thin film. The crystal field and the spin-orbit splitting energies for the valence band of the $ZnAl_2Se_4$ were estimated to be 109.5 meV and 124.6 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $ZnAl_2Se_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-exciton for n = 1 and $C_{21}$-exciton peaks for n = 21.

• Journal of Sensor Science and Technology
• /
• v.23 no.2
• /
• pp.134-141
• /
• 2014

A stoichiometric mixture of evaporating materials for $BaIn_2Se_4$ epilayers was prepared from horizontal electric furnace. To obtain the single crystal thin films, $BaIn_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $620^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the epilayers was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $BaIn_2Se_4$ epilayers measured from Hall effect by van der Pauw method are $8.94{\times}10^{17}cm^{-3}$ and 343 $cm^2/vs$ at 293 K, respectively. The temperature dependence of the energy band gap of the $BaIn_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)$=2.6261 eV-$(4.9825{\times}10^{-3}eV/K)T^2/(T+558 K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $BaIn_2Se_4$ have been estimated to be 116 meV and 175.9 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $BaIn_2Se_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1-$, $B_1$-exciton for n = 1 and $C_{21}$-exciton peaks for n=21.

• Restorative Dentistry and Endodontics
• /
• v.28 no.4
• /
• pp.334-340
• /
• 2003

This study was performed to evaluate the actual temperature rise on the surface of Buchanan plugger using thermocouple. The heat carrier system 'System B Heatsource'(Model 1005, Analytic Technologies, Redmond, WA, USA) and the Buchanan pluggers of F, FM, M and ML sizes are used for this study. The temperature was set to 200^{\circ}C on digital display and the power level on it was set to 10. Five thermocouples were placed in direct contact with the surface of each size of Buchanan's pluggers at 1 mm increments from the tip to the 4 mm length of shank. The heat control spring was touched for 5 seconds. and the temperature rise on the surface of the pluggers were measured at 1 sec intervals for more than 5 seconds with an accuracy of 0.01 using Data Logger. The data were statistically analyzed by one-way ANOVA. The results were as follows. 1. The position at which the temperature peaked was approximately at 1~2 mm far from the tip of Buchanan plugger (p<0.01). 2. The peak temperature was $215.25{\pm}2.28^{\circ}C$ in F plugger. $185.94{\pm}2.19^{\circ}C$ in FM plugger, $169.51{\pm}9.12^{\circ}C$ in M plugger, and 160.79{\pm}1.27^{\circ}C in ML plugger and the peak temperature was highest in F plugger and followed by. in descending order. FM plugger. M plugger. ML plugger showed the lowest peak temperature (p<0.01). 3. The temperature on the plugger was decreased with the increase of touching time. This results suggest that the actual temperature on the surface of the pluggers does not correlate well with the temperature set on digital display. Heat concentrates around the tip. The larger plugger reveals lower temperature rise relatively.

• Korean Journal of Psychosomatic Medicine
• /
• v.5 no.1
• /
• pp.3-11
• /
• 1997

In becoming parents, the marital partners enter into a new developmental phase. The conception of the child is an act of mutual creativity during which the boundaries between the self and another were temporarily obliterated more completely than at any time since infancy. The infant is a physical fusion of the parents, and their personalities unite within the child. for many women, creativity as a mother becomes a central matter that provides meaning and balance to their lives. The husband usually has strong desires for an offspring and can be transformed by it. The child can profoundly affect one or both parents, and the influences are reciprocal-a child's needs or specific difficulties uncover a parent's inadequacy. following the child's development, each transition into a new developmental phase requires an adaptation by the parents, and one or another of these required adaptations may disturb a parent's equilibirium. And the personality changes, emotional difficulties, and regressions of a spouse that occur in response to some phase of parenthood can upset the marriage. Not only do children identify with parents, but parents also identify with their children. The parents take pleasure in child's joy and suffer with the child's pain more than in almost any other relationship. certain respects e parents lives again in the child. Through the process of identification the child can also provide one of the two parents with the opportunity to experience intimately the way in which a person of the opposite gender grows up. Parenthood also provides the opportunity to be loved, admired, and needed simply because one is a parent and, as such, a central and necessary object in the young child's life. The many potentialities for emotional satisfactions from parenthood manage to outweigh the tribulations and sacrifices that are required. The child also exerts an indirect effect through changing the parent's position in the society, for new sets of relationships are established as the parents are drawn to other couples with children of the same age, and for a new impetus toward economic and social mobility often possesses the parents. frequently the couple's relatedness to their own parents improves and grows firmer once again. Parenthood, the satisfactions it provides and the demands it makes, varies as life progresses : and changes with the parent's interests, needs, and age as well as with the children's maturation. There are phases in the child's life that the parents are reluctant to have pass, whereas they tolerate others largely through knowing that they will soon be over. The changing lives of the children provide many satisfactions that offset the tribulations, uncertainties, and regrets. The parents change. The young father, who was just starting on his carrier whom the first child was born, settles into a life pattern. He becomes secure with increasing achievement and interacts differently with the youngest child and provides a different model for him than for the oldest. The mother may have less time for a second or third child than for her first, but she may also be more assured in her handling of them. The birth of a baby when the parents art in their late thirties will find them Less capable of physical exertion with the child and less tolerant of annoyances, but they are less apt to be annoyed. Eventually the children min and leave home, but the couple do not cease to be parents.

• Journal of Korea Port Economic Association
• /
• v.27 no.2
• /
• pp.313-331
• /
• 2011

Due to have been more keen in East-North Asia Hub Port competition, to be accelerated Busan New Port development, and to result to supply excess position, Busan port has been confronted by many problems. Also, as facilities of North Port is old, it is impossible to secure 16m depth of water at North Port, and North Port redevelopment is being, container traffic of North Port is accelerated to shift at New Port. Therefore, it. is time to seek for connection growth plan of succeeding together-Busan North & New Port as soon as possible. Connection growth plan of succeeding together-Busan North & New Port is focused, as follows. First, it is required to set up model for connection growth plan of succeeding together-Busan North & New Port. It is valid to specialize for ULCC, to promote to global port at New Port, and it is effective to focus on feeder service and general cargo handling, and to include most space to North Port redevelopment. Second, through port function reorganization, it is required to create a synergy by port function clustering. Third, through effective connection traffic network expansion for moving T/S cargo effectively, it is required to develop Busan Port for T/S cargo-focused port. Fourth, it is required to develop port hinterland logistics zone for creating container traffic through connection development of New Port-BJFEZ. Finally, it is required to build SCM system for creating container traffic among shipper, carrier, freight forwarder and related institution.

• Journal of Positioning, Navigation, and Timing
• /
• v.6 no.3
• /
• pp.125-133
• /
• 2017

Time comparison is necessary for the verification and synchronization of the clock. Two-way satellite time and frequency (TWSTFT) is a method for time comparison over long distances. This method includes errors such as atmospheric effects, satellite motion, and environmental conditions. Ionospheric delay is one of the significant time comparison error in case of the carrier-phase TWSTFT (TWCP). Global Ionosphere Map (GIM) from Center for Orbit Determination in Europe (CODE) is used to compare with Bernese. Thin shell model of the ionosphere is used for the calculation of the Ionosphere Pierce Point (IPP) between stations and a GEO satellite. Korea Research Institute of Standards and Science (KRISS) and Koganei (KGNI) stations are used, and the analysis is conducted at 29 January 2017. Vertical Total Electron Content (VTEC) which is generated by Bernese at the latitude and longitude of the receiver by processing a Receiver Independent Exchange (RINEX) observation file that is generated from the receiver has demonstrated adequacy by showing similar variation trends with the CODE GIM. Bernese also has showed the capability to produce high resolution IONosphere map EXchange (IONEX) data compared to the CODE GIM. At each station IPP, VTEC difference in two stations showed absolute maximum 3.3 and 2.3 Total Electron Content Unit (TECU) in Bernese and GIM, respectively. The ionospheric delay of the TWCP has showed maximum 5.69 and 2.54 ps from Bernese and CODE GIM, respectively. Bernese could correct up to 6.29 ps in ionospheric delay rather than using CODE GIM. The peak-to-peak value of the ionospheric delay for TWCP in Bernese is about 10 ps, and this has to be eliminated to get high precision TWCP results. The $10^{-16}$ level uncertainty of atomic clock corresponds to 10 ps for 1 day averaging time, so time synchronization performance needs less than 10 ps. Current time synchronization of a satellite and ground station is about 2 ns level, but the smaller required performance, like less than 1 ns, the better. In this perspective, since the ionospheric delay could exceed over 100 ps in a long baseline different from this short baseline case, the elimination of the ionospheric delay is thought to be important for more high precision time synchronization of a satellite and ground station. This paper showed detailed method how to eliminate ionospheric delay for TWCP, and a specific case is applied by using this technique. Anyone could apply this method to establish high precision TWCP capability, and it is possible to use other software such as GIPSYOASIS and GPSTk. This TWCP could be applied in the high precision atomic clocks and used in the ground stations of the future domestic satellite navigation system.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.33 no.5
• /
• pp.405-418
• /
• 2007

Mesenchymal stem cells(MSCs) have been though to be multipotent cells that can replicate that have the potential to differentiate into lineages of mesenchymal tissue including the bone, cartilage, fat, tendon, muscle, and marrow stroma. Especially, scaffolds to support cell-based tissue engineering are critical determinants of clinical efforts to regenerate and repair the body. Selection of a matrix carrier imvolves consideration of the matrix's role as a scaffold for physical support and host tissue integration as well as its ability to support of synergize the osteoinductive program of the implanted mesenchymal stem cell. The aim of this study is to evaluate the effect of autobone and Bio-$Oss^{(R)}$ to adherent mesenchymal stem cells as scaffolds on sinus augmentation with fibrin glue mixture in a rabbit model. 16 New Zealand White rabbits were divided randomly into 4 groups based on their time of sacrifice(1, 2, 4 and 8 weeks). First, mesenchymal stem cells were isolated from iliac crest marrow of rabbits and expanded in vitro. Cell culture was performed in accordance with the technique described by Tsutsumi et al. In the present study, the animals were sacrificed at 1, 2, 4 and 8 weeks after transplantation, and the bone formation ability of each sides was evaluated clinically, radiologically, histologically and histomorphologically. According to the histological observations, autobone scaffolds group showed integrated graft bone with host bone from sinus wall. At 2 and 4 weeks, it showed active newly formed bone and neovascularization. At 8 weeks, lamellae bone was observed in sinus graft material area. Radiologically, autobone with stem cell showed more radiopaque than Bio-$Oss^{(R)}$ scaffolds group. there were significant differences in bone volume between 4 and 8 weeks(p<0.05).