• Journal of the Korean Society of Radiology
• /
• v.11 no.2
• /
• pp.157-165
• /
• 2017

The active transport characteristics of $K^+$ and $Na^+$ pumping system of cell membrane model which irradiated by high energy x-ray(linac 6MeV) was investigated. The cell membrane model used in this experiment was a $Na^+$ type sulfonated copolymerized membrane of styrene and divinylbenezene. The initial flux of the ion was increased with increase of both $H^+$ ion concentration. In this experiment range(pH 1.5-5, temperature $36.5^{\circ}C$), the initial flux of $K^+$ which was not irradiated by radiation was found to be from $2.09{\times}10^{-4}$ to $1.32{\times}10^{-3}mole/cm^2{\cdot}h$ and that of $Na^+$ from $7.09{\times}10^{-4}$ to $1.09{\times}10^{-3}mole/cm^2{\cdot}h$. the initial flux of $K^+$ which was irradiated by radiation was found to be from $21.0{\times}10^{-4}$ to $16.7{\times}10^{-3}mole/cm^2{\cdot}h$ and that of $Na^+$ from $62.0{\times}10^{-4}$ to $20.6{\times}10^{-3}mole/cm^2{\cdot}h$. The ratio $K^+$/$Na^+$ of membrane was about 1.10. And the driving force of pH of irradiated membrane was significantly increased about 9-20 times than membrane which was not irradiated. As active transport of $K^+$ and $Na^+$ of cell membrane model were abnormal, cell damages were appeared at cell.

• Korean Management Science Review
• /
• v.3
• /
• pp.58-61
• /
• 1986

본 고는 P사의 원료 수급에 관한 계량적 모델을 제시함으로써 문제의 규모와 복잡성 때문에 해결이 어려웠던 문제를 단계적 의사결정에 의해 접근함으로써 현상의 이해와 더불어 실제 응용을 가능케하기 위한 시도의 일환이다. 먼저 고려되어야 할 적정 재고수준의 산정과 배선계획은 향후 기술하기로 하며 컴퓨터의 발전과 더불어 조직적인 문제해결을 위한 계량적 모델을 통한 접근방법의 한 예를 기술하였다.

• The Korean Journal of Pesticide Science
• /
• v.9 no.4
• /
• pp.279-286
• /
• 2005

The herbicidal activities against pre-emergence barnyard grass (Echinochloa crus-galli) by a series of new 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-phenylpopionamide derivatives as substrate molecule were studied using molecular holographic (H) quantitative structure activity relationships (HQSAR) methodology. From the based on the findings, the higher herbicidal active compounds are predicted by the derived HQSAR model. The best HQSAR model (VI-1) was derived from fragment distinction combination of atoms/bonds in fragment size, $7{\sim}10$bin. The herbicidal activities from atomic contribution maps showed that the activity will be able to increased according to the R-substituents variation of the N-phenyl ring and change of 6-chloro-2-benzoxazolyloxy group. Based on the results, the statistical results of the best HQSAR model (VI-1) exhibited the best pedictability and fitness for the herbicidal activities based on the cross-validated value ($q^2=0.646$) and non cross-validated value ($r^2_{ncv.}=0.917$), respectively. From the graphical analyses of atomic contribution maps, it was revealed that the lowest herbicidal activitics depends upon the 4-(6-chloro-2-benzoxazolyloxy)phenoxy group ($pred.pI_{50}=-3.20$). Particularly, the R=4-fluoro, X=isobutoxy substituent (P2) of (X)-phenoxy-N-(R)-phenylpropionamide derivative is predicted as the highest active compound ($pred.pI_{50}=9.12$).

• The Journal of Korean Academy of Prosthodontics
• /
• v.57 no.2
• /
• pp.102-109
• /
• 2019

Purpose: The purpose of this study was to evaluate the accuracy of three types of intraoral scanners and the accuracy of the single abutment and bridge abutment model. Materials and methods: In this study, a single abutment, and a bridge abutment with missing first molar was fabricated and set as the reference model. The reference model was scanned with an industrial three-dimensional scanner and set as reference scan data. The reference model was scanned five times using the three intraoral scanners (CS3600, CS3500, and EZIS PO). This was set as the evaluation scan data. In the three-dimensional analysis (Geomagic control X), the divided abutment region was selected and analyzed to verify the scan accuracy of the abutment. Statistical analysis was performed using SPSS software (${\alpha}=.05$). The accuracy of intraoral scanners was compared using the Kruskal-Wallis test and post-test was performed using the Pairwise test. The accuracy difference between the single abutment model and the bridge abutment model was analyzed by the Mann-Whitney U test. Results: The accuracy according to the intraoral scanner was significantly different (P < .05). The trueness of the single abutment model and the bridge abutment model showed a statistically significant difference and showed better trueness in the single abutment (P < .05). There was no significant difference in the precision (P = .616). Conclusion: As a result of comparing the accuracy of single and bridge abutments, the error of abutment scan increased with increasing scan area, and the accuracy of bridge abutment model was clinically acceptable in three types of intraoral scanners.

• Korean Journal of Agricultural Science
• /
• v.22 no.1
• /
• pp.103-109
• /
• 1995

The model foods were prepared by simulating mositure, protein and starch, and they were heated for 30 mins, at $80^{\circ}C$ and then cooled at $25^{\circ}C$ in water bath. Their rheological properties were investigated by the use of Brookfield wide-gap rotational viscometer at $30{\sim}60^{\circ}C$, and the rotation speed ranged from 0.6 to 6 rpm and solid content ranged from 8% to 11%, the results obtained were as follows. 1. All the model foods ($P_1S_3$, $P_2S_2$, $P_1S_1$, $P_2S_1$, $P_3S_1$, $P_4S_0$) exhibited pseudoplastic behaviors with yeild stress and were thixotropic foods which showed time - dependent structural decays, but the starch food of 8 ~ 11 % solid content did not show the flow behavior. 2. The correlation between the rheological parameters and the protein content of model foods in various moisture content did not appeared a constant relationship. 3. The change of shear stress against shear rate in high starch foods was larger than that in high protein foods and the structure at initial shear time was decayed with a quatic equation according to the Tiu's Model and structural decay was in parallel with the increase of shear rate. 4. The temperature dependency of the apparent viscosity of $P_1S_2$, and $P_2S_1$ was fully expressed by Arrhenius equation and activation energies of their food were 2.35 and $1.34Kcal/g{\cdot}mol$, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.8
• /
• pp.277-286
• /
• 2020

This study aimed to examine bone health awareness and knowledge and the bone mass-improving behaviors of female nursing college students. The subjects were 172 nursing students attending nursing colleges. The data were collected from March 16 to April 4, 2020, by using bone health awareness, bone health knowledge, and bone mass-promoting behavior assessment tools. Descriptive statistics are presented, and t-tests, ANOVA, Pearson's correlation, and multi-regressions were used for data analysis. Students' bone health awareness was 1.79, bone health knowledge was 8.86, and bone mass-promoting behavior level was 2.78. There were significant negative correlations between bone mass-promoting behavior level and age of menarche (r = 0.21, p = .004) and sun exposure (r = 0.44, p < .000). Also, bone mass-promoting behavior level and knowledge of bone health were negatively correlated (r = 0.21, p = .005). Regression analysis showed that knowledge of bone health (β = 0.21, p = .005), age of menarche (β = 0.20, p = .005), and sun exposure (β = 0.38, p < .000) were significant predictors of bone mass-promoting behaviors and their variance explanation power was 20.6%. Based on these results, education to improve knowledge of bone health will help to improve bone health and increase bone mass-promoting behaviors among young women.

• Tunnel and Underground Space
• /
• v.25 no.4
• /
• pp.341-358
• /
• 2015

This study analyzes the relationship between parameters of the discontinuity in Discrete Fracture Network model such as fracture intensity, fracture orientation, fracture size, fracture shape etc. In this paper, FracMan code was used to model and analyze 3D DFN. A sensitivity analysis was performed in order to analyze the relationship between linear fracture intensity measure ($P_{10}$) and parameters of the discontinuity in $100m{\times}100m{\times}100m$ model area. As a result the sensitivity analysis showed that key parameters affecting fracture intensity are fracture orientation (Trend / Plunge). Conversion factor($C_{13}$) for $P_{10}$, to calculate volumetric fracture intensity measure ($P_{32}$), is derived in case of vertical well and horizontal well when trend is $10^{\circ}$, $30^{\circ}$, $60^{\circ}$, $90^{\circ}$, $120^{\circ}$, $150^{\circ}$, $180^{\circ}$ (7cases) and plunge is $5^{\circ}$, $15^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, $75^{\circ}$, $85^{\circ}$ (7cases). It is expected that this paper can be used effectively for modeling and understanding DFN model.

• Journal of the Korean Society of Radiology
• /
• v.7 no.1
• /
• pp.85-91
• /
• 2013

The selective transport characteristics of $K^+$ and $Na^+$ of cell membrane model which irradiated by 60Co ${\gamma}$-ray was investigated. The cell membrane model used in this experiment was a Na+ type sulfonated copolymerized membrane of styrene and divinylbenezene. The initial flux of the ion was increased with increase of both $H^+$ ion concentration. In this experiment range(pH 0.5-3, temperature $15-65^{\circ}C$), first, the selectivity of $K^+$ and the ratio K+/Na+ of membrane which was not irradiated was about 1.06 - 1.13 and second, that of K+ and the ratio $K^+/Na^+$ of membrane which was irradiated was near about 0. And the driving force of pH of irradiated membrane was significantly increased about 4-5 times than membrane which was not irradiated. As selective transport of K+ and Na+ of cell membrane model were abnormal, cell damages were appeared at cell.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.48 no.3
• /
• pp.302-312
• /
• 2021

The purpose of this study was to develop prototype of virtual reality(VR) simulation with malocclusion models and evaluate its applicability. Task abilities, task completion time, and a satisfaction survey were compared between dentist trainees and dental students. Participants were instructed to observe virtual malocclusion models and then performed three tasks to diagnose the type of malocclusion, determine clinical findings and develop treatment plans. Their satisfaction with the simulation experience were evaluated using a questionnaire containing five questions. Task abilities of trainees related to clinical features and treatment plans were significantly higher than that of students(p < 0.01). In both groups, the task completion time for the second case was significantly reduced compared to that for the first case(p < 0.01). The satisfaction survey showed high scores and positive responses for this simulation in both groups. If the prototype of VR simulation is continuously advanced, it will be applicable for orthodontic education in pediatric dentistry.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.17 no.3
• /
• pp.304-309
• /
• 2007

What is important in ubiquitous computing is collecting users' context information from various sensors and providing services suitable for use's current situation. Particularly in mobile environment, each area has different context awareness structure and this makes it difficult to share information with other areas. As a result, context resources for recognizing users' context ate insufficient. Moreover, because mobile devices have a limited processing capacity, there are difficulties in the real time analysis of users' context. This paper proposed a context awareness and integration model for analyzing users' context actively and providing adaptive services using mobile devices. The proposed model distinguishes users' context between dynamic and static structure to analyze the context, and obtains context resources by sharing context information of users within an area.