• Applied Microscopy
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• 제44권4호
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• pp.111-116
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• 2014

This study investigates the developmental pattern of adhesive discs (ADs) to highlight the ontogeny and structural changes that occur during the growth of Boston ivy. Initiation to postmortem features of ADs were examined through light and scanning electron microscopy. The study also reveals a new finding of the dislocation of peripheral tissues of adaxial origin. Four phases of attachment are suggested with regards to its climbing behavior: 1) pre-attachment, 2) upon attachment, 3) after attachment, and 4) final attachment. During initiation, several ADs originate from tendril primordia without epidermal differentiation. However, different growth rates in the epidermis results in completely different ADs. ADs were discerned by size, shape, and color during expansion, but cells in the adaxial surface remained alive longer than the other side. Upon contact, the ADs demonstrate simultaneous growth and deterioration, but once attachment is established the latter process subdues to final stages. Epidermal transformation, adhesive secretion, cellular disruption, and mechanical stress were essential for the self-clinging nature of Boston ivy. The post-attachment sequence is also believed to be critical in achieving maximum mechanical strength to provide extensive support. The developmental process of ADs is prompted by tactile stimulation but in a highly organized and systematic manner.

• The Journal of Korean Physical Therapy
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• 제23권1호
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• pp.67-75
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• 2011

Purpose: This study aimed to analyze factors that influence the job satisfaction of physical therapists working in hospitals. Methods: The study was done using a self-administered questionnaire associated with job satisfaction, which was completed by 352 physical therapists working in hospitals. Results: The average job satisfaction score was 3.16. Sub-items scores for job satisfaction were higher for overall satisfaction (3.21) and lower for job satisfaction of achievement (3.12) than the average score. Job satisfaction of subjects showed statistically significant differences with regard to differences in sex, marriage, type of hospital, year of total career, type of patients and motivation level (p<0.05). The average job stress score was 2.38. The sub-items of job stress consisted of problems pertaining to physical environment (2.28), job demand (2.54), job autonomy (2.31), social support (2.14), job instability (2.36), organized management system (2.44), inner motive (2.24), and job culture (2.26). Multiple regression analysis revealed that job satisfaction became significantly lower with increasing levels of job stress. Conclusion: These results suggest that the job stress of physical therapists is closely related to their job satisfaction. An effort to reduce job stress may be helpful in improving the health and quality of life of physical therapists who work in hospitals.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.359-359
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• 2010

Self-organized nanostructures of dots, holes or ripples produced by energetic ion bombardment have been reported in a wide variety of substrates. Ion bombardment on an alloy or compound also draws much attention because it can induce a surface composition modulation with a topographical surface structure evolution. V. B. Shenoy et al. further suggested that, in the case of alloy surfaces, the differences in the sputtering yields and surface diffusivities of the alloy components will lead to a lateral surface composition modulation [1]. In the present work, the classical molecular dynamics simulation of Ar bombardment on metallic alloys at room temperature revealed that this bombardment induces a surface composition modulation in layer-by-layer mode. In both the $Co_{0.5}Cu_{0.5}$ alloy and the CoAl B2 phase, the element of higher-sputtering yield is accumulated on the top surface layer, whereas it is depleted in lower layers. A kinetic model considering both the rearrangement and the sputtering of the substrate atoms agrees with the puzzling simulation results, which revealed that the rearrangement of the substrate atoms plays a significant role in the observed composition modulation.

• 대한한의학방제학회지
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• 제29권4호
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• pp.253-266
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• 2021

Objective : This is to analyze the factors affecting the satisfaction of curriculum at korean medicine college and suggest the direction of the curriculum reformation of korean medicine colleges. Method : The collected data were conducted multiple linear regression analysis using the SPSS ver.26 statistical program, using 'curriculum satisfaction' as a dependent variable after analyzing the frequency of each variable. Result : The average score for curriculum satisfaction at Korean Medicine college was 2.87 points, which was relatively low. The factors affecting the satisfaction of the curriculum were 'A favorable impression of Korean Medicine College of W University' β=0.351(p<.001), 'connectivity between major subjects' β=0.312(p<.001), 'duplex between major subjects' β=-0.163(p<.05), 'recognition of the importance of Chinese characters' β=0.114(p<.0.5). Conclusion : The curriculum of Korean Medicine College should first, be organized to allow students to be proud of themselves, second, the goal of education should set goals optimized for job competency, third, the content of learning should be consisted of student led problem based learning, fourth, the link between major subjects should be intensified, fifth, the clinical practice time should be expanded significantly and lastly the assessment evaluates the performance process.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1213-1237
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• 2019

Vehicular Ad-hoc Network (VANET) facilities envision future Intelligent Transporting Systems (ITSs) by providing inter-vehicle communication for metrics such as road surveillance, traffic information, and road condition. In recent years, vehicle manufacturers, researchers and academicians have devoted significant attention to vehicular communication technology because of its highly dynamic connectivity and self-organized, decentralized networking characteristics. However, due to VANET's high mobility, dynamic network topology and low communication coverage, dissemination of large data packets (e.g. multimedia content) is challenging. Clustering enhances network performance by maintaining communication link stability, sharing network resources and efficiently using bandwidth among nodes. This paper proposes a mobility-based, multi-hop clustering algorithm, (MBCA) for multimedia content broadcasting over an IEEE 802.11p-LTE-enabled hybrid VANET architecture. The OMNeT++ network simulator and a SUMO traffic generator are used to simulate a network scenario. The simulation results indicate that the proposed clustering algorithm over a hybrid VANET architecture improves the overall network stability and performance, resulting in an overall 20% increased cluster head duration, 20% increased cluster member duration, lower cluster overhead, 15% improved data packet delivery ratio and lower network delay from the referenced schemes [46], [47] and [50] during multimedia content dissemination over VANET.

• 한국보건간호학회지
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• 제33권1호
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• pp.33-46
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• 2019

Purpose: Individuals suspected Middle East Respiratory Syndrome (MERS) are continuously surfacing in Korea. study the Korean public's knowledge, attitude, and preventive behaviors related to MERS as well as the factors that affect preventive behaviors for MERS. Methods: The study used a descriptive research design, and included 196 men and women aged 20 to 65 years. Data were collected through Internet surveys and self-reported questionnaires from December 1 to 30, 2017. Results: Among the participants, 88.7 percent knew cough etiquette, 84.7 percent had education about cough etiquette, and 52.6 percent had received education on MERS. The average scores for knowledge of MERS was $73.60{\pm}18.78$; attitude of MERS, $2.22{\pm}0.92$; and preventive behaviors for MERS, $62.43{\pm}16.11$. egression analysis showed that higher knowledge of MERS (${\beta}=.34$, p<.001) and higher attitude of MERS (${\beta}=.05$, p=<.001) resulted in increased preventive behaviors, people with MERS education increased preventive behaviors (${\beta}=.21$, p=.003). Conclusion: the awareness and knowledge of MERS for promoting related preventive behaviors. Therefore, education content that considers the characteristics of the target population should be organized and expanded multiple channels.

• International Journal of Computer Science & Network Security
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• 제22권11호
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• pp.241-247
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• 2022

Ad hoc network is self-organized network powered by battery. The reliability of virtual user identification and channel security are reduced when SNR is low due to limited user energy. In order to solve this problem, a joint virtual user identification and channel security en/decoding method is proposed in this paper. Transmitter-receiver-based virtual user identification code is generated by executing XOR operation between orthogonal address code of transmitter and pseudo random address code of receiver and encrypted by channel security code to acquire orthogonal random security sequence so as to improve channel security. In order to spread spectrum as well as improve transmission efficiency, data packet is divided into 6-bit symbols, each symbol is mapped with an orthogonal random security sequence. Subspace-based method is adopted by receiver to process received signal firstly, and then a judgment model is established to identify virtual users according to the previous processing results. Simulation results indicate that the proposed method obtains 1.6dB E_b/N₀ gains compared with reference methods when miss alarm rate reaches 10^-3.

• International Journal of Computer Science & Network Security
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• 제22권12호
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• pp.212-216
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• 2022

Space based constellation network is a kind of ad hoc network in which users are self-organized without center node. In space based constellation network, users are allowed to enter or leave the network at any given time. Thus, the number of active users is an unknown and time-varying parameter, and the performance of the network depends on how accurately this parameter is estimated. The so-called problem of active user identification, which consists of determining the number and identities of users transmitting in space based constellation network is discussed and a novel active user identification method is proposed in this paper. Active user identification code generated by transmitter address code and receiver address code is used to spread spectrum. Subspace-based method is used to process received signal and judgment model is established to identify active users according to the processing results. The proposed method is simulated under AWGN channel, Rician channel and Rayleigh channel respectively. Numerical results indicate that the proposed method obtains at least 1.16dB E_b/N₀ gains compared with reference methods when miss alarm rate reaches 10^-3.

• 한국식생활문화학회지
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• 제21권6호
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• pp.596-605
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• 2006

This study was conducted to investigate factors affecting gone density of university students in Seoul area. Data for food habits, exercise and health-related behaviors were obtained by self administered questionnaires. BQI(bone quality index) of the subjects was measured by an Quantitative Ultrasound(QUS). The results are summarized as follows: The average hight, weight BMI and osteopenia percentage of the male and female student were 173.3cm, 68.6kg, 22.7 and 24.2%; 161.4cm, 54.4kg, 20.9 and 55.5%, respectively. The BQI and Z-score of the subjects were 99.6, -0.3 in male student group, and 82.7, -1.1 in female student group, respectively. Height, weight, fat weight, fat mass and BMI were positively related with BQI in female group. BQI was positively affected by breakfast and frequence exercise in male student group. In female student group, frequency exercise was positively related with BQI. The result of this study revealed that the desirable food habits, dietary behaviors and health-related lifestyles may have a beneficial effect on bone density. They should have practically and systematically organized nutritional education on optimum body weight, good eating habits, weight bearing exercise for higher bone density level.

• International Journal of Stem Cells
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• 제17권1호
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• pp.30-37
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• 2024

The lung is a complex organ comprising a branched airway that connects the large airway and millions of terminal gas-exchange units. Traditional pulmonary biomedical research by using cell line model system have limitations such as lack of cellular heterogeneity, animal models also have limitations including ethical concern, race-to-race variations, and physiological differences found in vivo. Organoids and on-a-chip models offer viable solutions for these issues. Organoids are three-dimensional, self-organized construct composed of numerous cells derived from stem cells cultured with growth factors required for the maintenance of stem cells. On-a-chip models are biomimetic microsystems which are able to customize to use microfluidic systems to simulate blood flow in blood channels or vacuum to simulate human breathing. This review summarizes the key components and previous biomedical studies conducted on lung organoids and lung-on-a-chip models, and introduces potential future applications. Considering the importance and benefits of these model systems, we believe that the system will offer better platform to biomedical researchers on pulmonary diseases, such as emerging viral infection, progressive fibrotic pulmonary diseases, or primary or metastatic lung cancer.