• Journal of Magnetics
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• v.10 no.4
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• pp.137-141
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• 2005

We confirmed that the improvement in properties of magnetic tunnel junctions prepared by radical oxidation after thermal treatment was mostly resulted from the redistribution of oxygen at the $AIOx/Co_{90}Fe_{10}$ interface. The as-deposited Al oxide barrier was oxygen-deficient but most of it re-oxidized into $Al_2O_3$, the thermodynamically stable stoichiometric phase, through thermal treatment. As a result, the effective barrier height was increased from 1.52 eV to 2.27 eV. On the other hand, the effective barrier width was decreased from 8.2 ${\AA}$ to 7.5 ${\AA}$. X-ray absorption spectra of Fe and Co clearly showed that the oxygen in the CoFe layer diffused back into the Al barrier and thereby enriched the barrier to close to a stoichiometirc $Al_2O_3$ phase. The oxygen bonded with Co and Fe diffused back by 6.8 ${\AA}$ and 4.5 ${\AA}$ after thermal treatment, respectively. Our results confirm that controlling the chemical structures of the interface is important to improve the properties of magnetic tunnel junctions.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.82-82
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• 2015

Industrial crystalline silicon (c-Si) solar cells with using a screen printing technology share the global market over 90% and they will continue to be the same for at least the next decade. It seems that the $2^{nd}$ generation and the $3^{rd}$ generation technologies have not yet demonstrated competitiveness in terms of performance and cost. In 2014, new world record efficiency 25.6% (Area-$143.7cm^2$, Voc-0.740V, $Jsc-41.8mA/cm^2$, FF-0.827) was announced from Panasonic and its cell structure is Back Contact $HIT^*$ c-Si solar cell. Here, amorphous silicon passivated contacts were newly applied to back contact solar cell. On the other hand, 24.9% $TOPCon^{**}$ cell was announced from Fraunhofer ISE and its key technology is an excellent passivation quality applying tunnel oxide (<2 nm) between metal and silicon or emitter and base. As a result, to realize high efficiency, high functional technologies are quite required to overcome a theoretical limitation of c-Si solar cell efficiency. In this presentation, Si solar cell technology summarized in the International Technology Roadmap for Photovoltaics ($^{***}ITRPV$ 2014) is introduced, and the present status of R&D associated with various c-Si solar cell technologies will be reviewed. In addition, national R&D projects of c-Si solar cells to be performed by Korea University are shown briefly.

• PNF and Movement
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• v.11 no.1
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• pp.7-16
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• 2013

Purpose : The purpose of this study is to analyze the effect of the proprioceptive exercise program on balance performance in order to the suggest hemiplegic patients the therapeutic intervention. Methods : In this study, Proprioceptive exercise program was applied to 11 hemiplegic patients for 6 weeks as follows: First of all, hemi leg flexion-extension pattern was applied in a supine position. Secondly, alternated leg flexion pattern was applied in a standing posture with one hand support on the unstable platform. Thirdly, rhythmic stabilization techniques were applied in a standing posture on the unstable platform. Results : Significant differences were observed the chronic low back pain patient for VAS, BBS. Chronic low back pain patient improved all test. The results of this study were summarized as follows: 1. After intervention, there was a statistically significant change in the dynamic balance (FSST, TUG, FRT) performance(p<.05). 2. After intervention, there was also a statistically significant change in the static balance (FICSIT-4) performance(p<.05). Conclusion : The result of the study suggests that muscle strength exercise by the intervention of proprioceptive exercise program improves the hemiplegic patients' static and dynamic balance performance.

• Transactions of Materials Processing
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• v.33 no.1
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• pp.18-35
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• 2024

In the present work, the evolution rules for the internal variables including continuum damage factors are obtained using the thermodynamic framework, which are in turn facilitated to derive the elastic-plastic constitutive relation for the particulate composites. Using the Mori-Tanaka scheme, the homogenization on state and internal variables such as back-stress and damage factors is carried out to procure the rate independent plasticity relations. Moreover, the degradation of mechanical properties of constituents is depicted by the distinctive damages such that the phase and interfacial damages are treated individually accordingly, whereas the kinematic hardening is depicted by combining the Armstrong-Frederick and Phillips' back-stress evolutions. On the other hand, the present constitutive relation for each phase is expressed in terms of the respective damage-free effective quantities, then, followed by transformation into the damage affected overall nominal relations using the aforementioned homogenization concentration factors. An emphasis is placed on the qualitative analyses for strain localization by observing the perturbation growth instead of the conventional bifurcation analyses. It turns out that the proposed constitutive model offers a wide range of strain localization behavior depending on the evolution of various internal variable descriptions.

• Journal of Families and Better Life
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• v.28 no.1
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• pp.87-98
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• 2010

The purpose of the present study was to examine the desire of married women to be re-employed and the factors related to this desire. The study gathered information from 240 women who gave up their jobs and careers after marriage. Information included their career history, current psycho-social condition, and family situation. Multiple regression and covariation structure analyses indicated that the desire of married women to go back to paid work was influenced by family economic condition, psycho-social condition, and child care situation. Specifically, the study found that family's monthly income and the age of the last child were negatively related to the women's desire for re-employment. On the other hand, economic pressure and achievement motivation were positively related to the women's desire. Finally, the study found that socio-economic background and external social support were not significantly related to the women’s wish to go back to the workforce.

• Physical Therapy Rehabilitation Science
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• v.5 no.3
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• pp.138-142
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• 2016

Objective: The purpose of this study was to investigate how light touch with a finger affects balance ability when a posture is maintained in the condition of visual information blockage and to provide a fundamental material for developing balance ability in the process of rehabilitation treatment. Design: Cross-sectional study. Methods: The study subjects were 17 healthy men and women in their twenties and thirties who were studying at S University in Seoul. The system was comprised of an equilateral triangular force platform. Subjects were asked to step on the foot position of the force platform (Good Balance, Finland) barefooted for 30 seconds, with eyes closed, hands hanging down loosely, and feet comfortably apart. It was connected to a laptop by using Bluetooth technology. An experiment was conducted in the following three circumstances: 1) no-touch trial, 2) light touch to the back (T7 area), and 3) light touch to the middle finger of the left hand. Each subject was given a 10-minute break between consecutive measurements. The experimental circumstances were performed randomly. Anteroposterior sway (APSV), mediolateral sway velocity (MLSV), and velocity moment (VM) were measured. Results: The APSVs (mm/s) were $9.32{\pm}3.37$ and $5.45{\pm}2.98$; the MLSVs (mm/s), $6.39{\pm}3.35$ and $3.31{\pm}2.48$; and VM ($mm^2/s$), $17.13{\pm}11.75$ and $6.76{\pm}8.31$ in the first and second experimental circumstances, respectively. APSV, MLSV, and VM values were significantly improved with the 1) no-touch trial and 2) light touch to the back trail conditions compared with the 3) light touch to the middle finger of the left hand condition (p<0.05). Conclusions: This study revealed that the balance ability for maintaining a body posture was influenced more by light touch to the back (T7) than by light touch with the sensitive fingertip and body sway diminished after visual information was blocked.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.227-237
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• 2007

The purpose of this study was to examine the effect of precision that kinematics had when short approach shots were taken. In this study, the subjects chosen were 5 skilled and 5 unskilled subjects, who were allowed to shoot 10 rounds of shots at target distances of 1m, 2m, 4m, and 8m. Three dimensional analysis was used as methods to obtain kinematics of each shots. In order to verify the statistical significance of the kinematic factors followed by the results of different skills and target distances, we used the two-way repeated ANOVA. The study was experimented within the level of p<.05. The results obtained were as follows: 1) the difference of shots of the forward and backward variations were larger than those of the left and right variations, the unskilled subjects' shot distances greatly got larger than that of the skilled subjects as the distance of the target increased, 2) not being affected by the target distance variations, the skilled subjects' rate of down-swing was shorter than the back-swing on short approach shots, 3) the skilled subjects' center of body weight tended to move more naturally towards the target when doing the down-swing to finish than that of the unskilled subjects on short approach shots, 4) the skilled subjects' right hand angle of cocking were narrower and tended to be kept much more consistent than that of the unskilled subjects on short approach shots, 5) the unskilled subjects when doing their back-swings, their right hips swayed towards the back, their trunk-flexion angles were shown to be lower than that of the skilled subjects on short approach shots, 6) the skilled subjects`body weight tended to move more naturally towards the left foot when doing the down-swing to finish than that of the unskilled subjects on short approach shots.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.5
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• pp.693-698
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• 2012

This study was designed to investigate the effects of 1-fluoro-2,4 dinitrobenzene (DNFB) on Induction of dermatitis in mice. We investigated the effects of DNFB on induction of dermatitis in terms of changes in body weights, ear thickness, ear weight, spleen/body ratio, histopathological observation and cytokine productions in inflammed tissue of contact dermatitis (CD) mice. In our experiments, we induced CD by using two different methods. First, mice were sensitized and challenged on the back of each ear (topical induction). Second, mice were sensitized on shaved back and challenged back of each ear (systemic induction). In our results, average weights were lowered in both topical and systemic group. But, there was no statistical significance between topical and systemic group. Treatment with DNFB enlarged ear weights and thicknesses in both topical and systemic groups. In addition, both groups were showed almost same features such as immune cell infiltration, spongiosis and hyperplasia in histopathological observations. Finally production levels of TNF-a, IFN-g and IL-6 were markedly elevated in both topical and systemic groups. On the other hand, systemic induction was more effective in spleen/body ratio and IL-6 production compared to topical induction respectively. These results suggest that dermatitis model using DNFB was used as model of CD, not for atopic dermatitis model.

• Journal of Fashion Business
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• v.9 no.4
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• pp.145-160
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• 2005

On the subjects of the female adults in their 20s who love to wear jeans, the wearing reality of basic jean pants and engineered jean pants was examined while pattern comparison and the evaluation of appearance and functions were made to reach the following conclusions: 1. Wearing reality of engineered jean pants Among the examined subjects, 74.8% were found out to favor engineered jean pants. Those who have engineered jean pants turned out to pursue well-known brands more than practicality. 2. Pattern comparison analysis of basic jean pants and engineered jean pants Though similar sizes existed in pants tips and belt width, engineered jean pants showed bigger values in waist circumference, crotch circumference, hip circumference, knee circumference, thigh circumference and so on. There were no big differences in the front part except for the items like crotch circumference and crotch length, but engineered jean pants had bigger sizes in the rear part. Engineered jeans in the rear contained the outward curved silhouette of the legs, curved tips, and a dart design instead of a back yoke. 3. Evaluation of appearance and functions In the scores of appearance, basic jean pants were higher at 3.65 in the order of front > side > back. On the contrary, engineered jean pants were excellent in the order of side > back > front. In the items of functions, engineered jean pants were higher at 4.23 in the order of hips > thighs> waist > abdomen > knee > crotch. On the other hand, basic jean pants showed the order of knee > crotch & thighs > abdomen > hips > waist. In every movement, engineered jean pants revealed higher functionality. In particular, the bigger physical movement led to the greater functional differences between the two kinds of jean pants.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.7
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• pp.571-574
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• 2010

Surface recombination loss should be reduced for high efficiency of solar cells. To reduce this loss, the BSF (back surface field) is used. The BSF on the back of the p-type wafer forms a p+layer, which prevents the activity of electrons of the p-area for the rear recombination. As a result, the leakage current is reduced and the rear-contact has a good Ohmic contact. Therefore, the open-circuit-voltage (Voc) and fill factor (FF) of solar cells are increased. This paper investigates the formation of the rear contact process by comparing aluminum-paste (Al-paste) with pure aluminum-metal(99.9%). Under the vacuum evaporation process, pure aluminum-metal(99.9%) provides high conductivity and low contact resistance of $4.2\;m{\Omega}cm$, but It is difficult to apply the standard industrial process to it because high vacuum is needed, and it's more expensive than the commercial equipment. On the other hand, using the Al-paste process by screen printing is simple for the formation of metal contact, and it is possible to produce the standard industrial process. However, Al-paste used in screen printing is lower than the conductivity of pure aluminum-metal(99.9) because of its mass glass frit. In this study, contact resistances were measured by a 4-point probe. The contact resistance of pure aluminum-metal was $4.2\;m{\Omega}cm$ and that of Al-paste was $35.69\;m{\Omega}cm$. Then the rear contact was analyzed by scanning electron microscope (SEM).