• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.213-220
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• 2022

Although there have been advances in cancer therapy and surgical improvement, lung cancer has the lowest survival rate (19%) at all stages. This is because most patients are diagnosed with concurrent metastasis, which occurs due to numerous related reasons. Especially, lung cancer is one of the most common and malignant cancers in the world. Although there are advanced therapeutic strategies, lung cancer remains one of the main causes of cancer death. Recent work has proposed that epithelial-mesenchymal transition (EMT) is the main cause of metastasis in most cases of human cancers including lung cancer. EMT involves the conversion of epithelial cells, wherein the cells lose their epithelial abilities and become mesenchymal cells involved in embryonic development, such as gastrulation and neural crest formation. In addition, recent research has indicated that EMT contributes to altering the cancer cells into cancer stem cells (CSCs). Although EMT is important in the developmental stages, this process also activates lung cancer progression, including complicated and diverse signaling pathways. Despite the numerous investigations on signaling pathways involved in the progression of lung cancer, this malignancy is considered critical for treatment. EMT in lung cancer involves many transcription factors and inducers, for example, Snail, TWIST, and ZEB are the master regulators of EMT. EMT-related factors and signaling pathways are involved in the progression of lung cancer, proposing new approaches to lung cancer therapy. In the current review, we highlight the signaling pathways implicated in lung cancer and elucidate the correlation of these pathways, indicating new insights to treat lung cancer and other malignancies.

• Journal of Labour Economics
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• v.25 no.1
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• pp.161-182
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• 2002

The self-employment can provide work time flexibility. Work time flexibility would be a critical factor for married females' labor supply considering allocation of their time to market work and household work. This study used the 1998 and 2000 Korea Labor and Income Panel Survey for the empirical analyses. Applying the bivariate probit model with partial observability, this study analyzed factors related to the choice of participation in labor market and choice of self-employment. Also, this study examined the effects of marriage and the presence of younger children on changes in decisions related to labor supply using the multinomial logit model: exit from the labor market, increasing and decreasing work hours. The presence of the younger children showed a significantly negative effect on the participation in labor market while positive, but insignificant, effect on self-employment. Compared with females working for others, self-employers without employees and unpaid family workers are less likely to exit labor market rather than increasing work hours. The self-employment would be a good alternative to evade females' career interruption and therefore to enhance the potential human resources.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.2
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• pp.102-110
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• 2010

Personal exposure relies on characteristics of time activity patterns of the population of concern as human activities impact the timing, location, and level of personal exposure. The information about time spent in microenvironments plays a critical role for personal exposure to air pollutants. It is useful to determine the precise times of the day that the subjects are in certain locations or engaging in specific activities because exposure to some air pollutants can depend on temporal trends. This study investigated time activity pattern for workers of Korean population over 19 years old with 8,778 workers in weekday. The residential indoor times were 12 hours. Time activity was different by gender and the mean times stayed at home in weekday were 12.9 hours in female and 11.42 hours in male, respectively. The major factors on residential indoor time and workplace time were age, monthly income, occupation and industry type, work position, education, and gender. Considering shorter than those in other countries, Korean workers spent less time at home after the working hours. Determinants of time activity pattern need to be taken into account in exposure assessment, epidemiological analyses, exposure simulations, as well as in the development of preventive strategies. Since there are substantial difference of Korean worker activity pattern, this information can be critical for exposure assessment in Korea.

• Journal of Sensor Science and Technology
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• v.26 no.3
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• pp.149-154
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• 2017

Detection of rain is one of the essential weather factors that are monitored by automatic weather stations in Korea. In this work, we studied the operation standards required for impedance-based rain detectors in terms of surface temperature and sensitivity, in an effort to establish a qualification procedure for rain detectors. The surface temperature of rain detectors was measured at varying air temperatures from $-30^{\circ}C$ to $20^{\circ}C$, considering the hypothetical presence and absence of rain/snow. In addition, the sensitivity of rain detectors was studied generating artificial raindrops of regular size. The sensitivity was evaluated in terms of the critical number of droplets that triggers the activation of the rain detector. We found that the sensitivity is affected by stationary, horizontal, and vertical droplet deposition methods. The critical number of droplets for the stationary deposition is higher than that for both horizontal and vertical depositions, which provides the maximum limit of droplets required to activate the detector. Based on our experiments considering surface temperature measurements and sensitivity tests, we suggest a revised version of surface temperature and sensitivity requirements for the qualification of impedance-based rain detectors.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.4
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• pp.71-80
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• 1990

Model tests for the ultimate pullout resistance of anchorages and investigation of failure behaviors in cohesionless soil have been conducted. The factors affecting the anchorage are mostly the geometry of the system, and soil properties of sands. The main conclusions of the experimental work were as follows. 1. The load - displacement relationship can be a form of parabolic curve for all plates. 2. The change in ultimate pullout resistance of anchor is mostly affected by embedment ratio and size of anchor, and influenced to a lesser degree by its shape. 3. Critical embedment ratio which is defined as the failure mode changes from shallow to deep mode is increased with increasing height of anchor. 4. For a constant anchor height, as the width of anchor increases the ultimate pullout resistance also increases. However, considering the efficiency of anchor for unit area, width of anchor does not appear to have any sigrnificant contribution on increasing anchor city. 5. Anchor capacity has a linear relation to sand density for any given section and the rate of change increases as the section increases. Critical depth determining the failure patterns of anchor is decreased with a decrease of sand density. 6. With increasing inclination angle, size of anchor, and decreasing embedment ratio, the ultimate pullout resistance of anchor under inclined loading is significantly decreased. 7. The ultimate pullout resistance of double anchor, a method of improving single of anchor capacity, is influenced by the center - to - center spacing adjacent anchors. It is also found that tandem and parallel anchor rigging arrangements decrease the anchor system capacity to less than twice the single anchor capacity due to anchor interference.

• Journal of Distribution Science
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• v.16 no.6
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• pp.77-84
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• 2018

Purpose - The aim of this study was to analyze the educational needs of distribution company salespeople in core competencies for convergence and their general perception of convergence education. Furthermore, this study provides basic data on core competencies for convergence needed by them. Research design, data, and methodology - A survey was conducted on 104 distribution company salespeople who worked near Seoul, Korea to analyze the perceptions of their educational needs in core competencies for convergence education, according to their socio-demographic characteristics. The socio-demographic characteristics were gender, age, workplace size, education background, work experience and business category. The questionnaire consisted of demographic factors (7 questions), general perception of convergence education (5 questions), perception of importance of core competency for distribution company salespeople (9 questions), and current perception of distribution company salespeople on core competency of convergence workers (9 questions). Park et al.(2014)'s categorization of convergence core competencies was used: Cognitive convergence (creative thinking, critical thinking and understanding of convergence knowledge), convergence performance (problem solving, communications, collaboration and application of convergence tools) and attitude toward convergence (empathy and responsibility). Data was collected through an independent sample of t-tests and a one-way analysis of variance and the Borich Needs Assessment Model was used to identify the educational needs of distribution company salespeople in the core competencies of convergence education. Results- The results show that the subjects recognized the need for convergence education to be high among the general perceptions. The perception scores for workers of different backgrounds only varied according to the size of the business. Moreover, the results of the educational needs analysis and the ranks of the required core competencies of convergence workers by the subjects were as follows: 1. convergence knowledge understanding competency, 2. creative thinking competency, 3. convergence tool application competency, 3. communications competency, 4. problem solving competency, 5. collaboration competency, 6. critical thinking competency, 7. empathy competency, 8. responsibility competency. Conclusions - This study highlights the necessity of developing university curriculum that can nurture the core competencies of conversion education reflecting distribution company salespeople's requests as well as cultivating qualified convergence workers required by distribution company workers.

• Journal of Korean Critical Care Nursing
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• v.8 no.1
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• pp.62-70
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• 2015

Purpose: This study is a descriptive research study to determine the level of professional autonomy, professional self-concept, and job satisfaction of emergency nurses, and to investigate their correlations and verify the effects of professional autonomy and professional self-concept on job satisfaction. Method: The subjects were 189 emergency nurses with a work experience of 1 year or more, in 14 hospitals located in B and U Metropolitan Cities. The study was conducted from July 20, 2014, to August 30, 2014. The measurement instruments for professional autonomy, professional self-concept, and job satisfaction were used as the measurement tools. The collected data were analyzed using the t-test, analysis of variance, Scheffe's test, Pearson's correlation coefficient, and multiple linear regression. Results: Job satisfaction among emergency nurses showed a significant positive correlation with professional autonomy (r=.28, p <.001), and with professional selfconcept (r=.50, p <.001) with sub-areas of professional practice (r=.79, p <.001), satisfaction (r=.64, p <.001), and communication (r=.25, p <.001). Factors affecting job satisfaction were satisfaction (${\beta}$=0.60, p <.001), followed by low professional autonomy (${\beta}$=-0.24, p <.001) and communication (${\beta}$=0.14, p =.008), which accounted in total for 48.3% of the effect. Conclusion: This study suggests that enhancing professional satisfaction, maintaining proper communication, and securing autonomy are required to improve the job satisfaction among emergency nurses.

• Journal of Korean Critical Care Nursing
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• v.15 no.3
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• pp.51-61
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• 2022

Purpose : This study aimed to verify the effectiveness of the clinical ladder system (CLS) by identifying the perception of the CLS, professional self-concept, self-efficacy, and organizational commitment among intensive care unit (ICU) nurses. Methods : Data were collected through a questionnaire survey of 173 nurses working in 11 ICUs at a tertiary hospital in Seoul. Results : The perception of the CLS, self-efficacy, and organizational commitment showed significant difference according to the CLS level. As a result of the partial Spearman correlation analysis after adjusting for demographic difference according to CLS (age, marital status, education, and clinical career), CLS positively correlated with the perception of the CLS (r=.16, p=.045), professional self-concept (r=.24, p=.001), and self-efficacy (r=.21, p=.007). On the contrary, organizational commitment negatively correlated with the perception of the CLS (r=-.43, p<.001) and self-efficacy (r=-.32, p<.001). Conclusion : The CLS is effective for professional self-concept and self-efficacy. However, specialists 2 nurses, who had high professional self-concept and self-efficacy, showed low level of organizational commitment. Thus, it is necessary to examine the factors of work burden and career plateau that are imposed after promotion and improve experience and planning according to the growth needs. Moreover, regular evaluation of the CLS will require hospital support to ensure that ICU nurses appreciate and actively participate in the support.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.435-437
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• 2002

Polishing of copper, a process called copper chemical mechanical polishing, is a critical, intermediate step in the planarization of silicon wafers. During polishing, the electrodeposited copper films are removed by slurries: and the differential polishing rates between copper and the surrounding silicon dioxide leads to a greater removal of the copper. The differential polishing develops dimples and furrows; and the process is called dishing and erosion. In this work, we present the results of experiments on dishing and erosion of copper-CMP, using patterned silicon wafers. Results are analyzed for the pattern factors and properties of the copper layers. Three types of pads - plain, perforated, and grooved - were used for polishing. The effect of slurry chemistries and pad soaking is also reported.

• Journal of Korean Academy of Nursing Administration
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• v.20 no.1
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• pp.106-116
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• 2014

Purpose: In this paper issues and challenges of the workforce policy for nursing were explored and appropriate policy responses identified. Results: Many countries, including South Korea, are facing a shortage of nurses. In South Korea, the number of practicing registered nurses is about half the average for Organization for Economic Cooperation and Development (OECD) member countries. The shortage of nurses is not necessarily a shortage of individuals with nursing qualifications but also includes complex issues, such as lack of well-educated nurses, shortage of nurses willing to work, and geographical imbalances of nurses. The present nurse workforce policies are to increase number of nursing schools, to reduce the length of training, and to replace nurses with nursing assistants. However, the findings of many studies have shown that these attempts resulted in a worsening of patient outcomes and increasingly low quality of care. Conclusion: The findings in this study indicate that nurse workforce policy should have a multi-faceted approach in order to address the many factors affecting nurse shortages.