• Journal of Biomedical Engineering Research
• /
• v.22 no.5
• /
• pp.393-402
• /
• 2001

A computational model representative of cardiovascular circulation was built using 12 standard lumped compartments. Especially, both the baroreceptor reflex and the cardiopulmonary reflex control model were implemented to explain the auto-regulation of cardiovascular system. Another important aspect of this model is to utilize the impulse-response curve of the nerve system in transferring the impulse error signals to autonomous nerve system. For the verification of this model, we have computed the normal hemodynamic conditions and compared those with the clinical data. Then. hemodynamic shock of 20% hemorrhage to cardiovascular system was simulated to test the effects of the control system model. The results of these two simulations were well matched with the experimental ones. The steady state LBNP simulation was also performed. The transient changes of hemodynamic variables due to ramp increase of bias pressure of LBNP showed good agreement with the physiological experiments. Numerical solution using only the baroreflex model showed relatively a larger deviation from the experimental data. compared with the one using the control model haying both the baroreflex and the cardiopulmonary reflex systems, which shows an important role of the cardiopulmonary reflex system for the simulation of the hemodynamic behavior of the cardiovascular system .

• Korean Business Review
• /
• v.21 no.2
• /
• pp.111-136
• /
• 2008

The central purpose of this study is to examine the relationships among learning and growth perspective, internal business process perspective, custom perspective, financial perspective, and general performance. To achieve this purpose, this study uses Kaplan and Norton's(1996) Balanced Scorecard Model theory. A field survey was undertaken through questionnaire sampling a population of construction companies. The data was collected from 185 firms in Korea for the analysis. The major findings of this study can be summarized as follows; Theoretical consideration and empirical study indicate statistically significant relationship(F=7.68, p=0.000). Especially, Financial perspective appeared to mediate the relationship between non-financial perspectives and general performance. It concludes that Non-financial perspectives significant affect the financial perspective and general performance. But, there are several limitations and directions for future research that should be noted. The potential limitation of this study concerns sampling and for selection process. Future research needs to reduce potential bias by collecting data which allows multiple industries for a subset of the sample.

• Journal of Korean Academy of Nursing
• /
• v.46 no.5
• /
• pp.619-629
• /
• 2016

Purpose: This study was a systematic review to evaluate the effects of aromatherapy on menopausal symptoms, perceived stress and depression in middle aged-women. Methods: Eight databases were searched from their inception September 8, 2015. Two reviewers independently performed the selection of the studies, data abstraction and validations. The risk of bias was assessed using Cochrane criteria. For analysis of the data, a meta-analysis of the studies was performed. Results: From the electronic databases, 73 articles were selected, and 19 removed due to duplication. After two reviewers read the abstracts of 54 studies, 34 studies were selected. Complete papers for 34 s were read and, 12 studies which met selection criteria were reviewed and the effects of aromatherapy on menopausal symptoms, stress and depression analyzed using meta-analysis with RevMan. In the 2 studies which included Randomized Controlled Trials testing of aromatherapy on menopausal symptoms and comparison of control and placebo groups were done. Aromatherapy massage was favorably effective in reducing the menopausal symptoms compared to the control group (n=118, MD=-6.33; 95% CI -11.51 to -1.15), and compared to the placebo group (n=117, MD=-4.14; 95% CI -7.63 to -0.64). Also aromatherapy was effective in reducing stress (n=72, SMD=-0.64; 95% CI -1.12 to -0.17) and depression (n=158, MD=-5.63; 95% CI -10.04 to -1.22). Conclusion: There is limited evidence suggesting that aromatherapy for middle-aged women may be effective in controlling menopausal symptoms, perceived stress and depression.

• Korean Journal of Acupuncture
• /
• v.24 no.4
• /
• pp.13-24
• /
• 2007

Objectives : This article aims to give guidance on the conduct and reporting of case series and audits of acupuncture, based on common problems that have arisen in the past. This type of project, and particularly the prospective case series or pre- post-intervention study, may give valuable evidence of the overall effectiveness of acupuncture-for example in different situations and in different conditions- and provides one step in the research pathway before generating an hypothesis. Results & Discussion : The project should be designed with the aim of reducing bias as much as possible. Careful and detailed planning is essential for the project to produce worthwhile results that readers can evaluate and replicate. Ethical issues should be considered and formal approval may be necessary. The patient group should be recruited systematically and baseline data obtained. The treatment given should be systematic and decisions to change or end treatment made explicit. The outcome should be measured in ways that are known to be reliable and valid. Musculoskeletal problems can be evaluated with scales for pain and confirmed by measuring one other symptom such as stiffness or one other aspect such as bothersomeness. Global change scores also provide supporting information, and the MYMOP (Measure Yourself Medical Outcome Profile) measure is popular when patients with different conditions are included. The design of questionnaires for beliefs and attitudes is a specialised area that should not be attempted without expert help. Adverse events should also be recorded. Analysis of the data and the best way of summarising and presenting the results are also discussed.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.87-90
• /
• 2005

The FORMOSAT-3/COSMIC mission is a micro satellite mission to deploy a constellation of six micro satellites at low Earth orbits. The final mission orbit is of an altitude of 750-800 lan. It is a collaborative Taiwan-USA science experiment. Each satellite consists of three science payloads in which the GPS occultation experiment (GOX) payload will collect the GPS signals for the studies of meteorology, climate, space weather, and geodesy. The GOX onboard FORMOSAT -3 is designed as a GPS receiver with 4 antennas. The fore and aft limb antennas are installed on the front and back sides, respectively, and as well as the two precise orbit determination (POD) antennas. The precise orbit information is needed for both the occultation inversion and geodetic research. However, the instrument associated errors, such as the antenna phase center offset and even the different cable delay due to the geometric configuration of fore- and aft-positions of the POD antennas produce error on the orbit. Thus, the focus of this study is to investigate the impact of POD antenna parameter on the determination of precise satellite orbit. Furthermore, the effect of the accuracy of the determined satellite orbit on the retrieved atmospheric and ionospheric parameters is also examined. The CHAMP data, the FORMOSAT-3 satellite and orbit parameters, the Bernese 5.0 software, and the occultation data processing system are used in this work. The results show that 8 cm error on the POD antenna phase center can result in ~8 cm bias on the determined orbit and subsequently cause 0.2 K deviation on the retrieved atmospheric temperature at altitudes above 10 lan.

• Journal of Advanced Navigation Technology
• /
• v.15 no.5
• /
• pp.705-713
• /
• 2011

In this paper, we introduce two techniques for resolving integer ambiguities between reference stations, which is one of the most important processes in Network RTK correction generation process. Each techniques uses Hatch filter and combination of L1/L2 measurements and we used simulation data and real data to evaluate performance of the techniques. For evaluating performance of each technique, we compared corrections generated from user site and Network RTK. As a result, Network RTK with the technique which uses Hatch filter improves user performance much more than single baseline RTK does. Residual of user is smaller than a half size of wavelength so it does not affect user integer ambiguity resolution, however, it contains significant bias error. On the other hand, when we used the technique which uses combination of L1/L2 measurements, residual error of user is largely reduced compared to the technique using Hatch filter.

• The Journal of Korean Medicine
• /
• v.26 no.2 s.62
• /
• pp.152-165
• /
• 2005

Background: The use of herbal preparations as remedies for various medical conditions has continuously increased in Korea Large proportions of Korean patients use herbal medicinal products, folk remedies, and food supplements. However, studies on the safety of herbal products arc conducted on a less than sufficient basis even in the countries like Korea where herbal medicine is being used extensively. Some of the reports on the safety of herbs were done by the doctors of western medicine but lack of knowledge and misclassification led to misunderstandings. Objecitves: This study aims to review the recent evidences on hepatotoxic events associated with the use of herbal medicinal products, folk remedy, and food supplements. In the process, this review will grasp trends in this field of studies and will direct further researches into the right direction. Methods: Systematic literature searches were performed on MedRic and MEDLIS in Korea. Screening and selection of the articles and the extraction of data were performed independently by two of authors. There were no restrictions regarding the published date. In order to avoid bias, the articles written by medical doctors, not by oriental doctors were selected. 43 journals were chosen for the review. Results: Analyzing the number of journals, studies on the drug-induced liver injury were increased after the year 2000. The proportion of herbal and folk remedy associated hepatotoxic injuries in all drug-induced liver injury was $21.0\%-30.0\%$. But criterion for herbal medicine is rather vague and limited objective data hindered objectiveness. Few of single medicinal herbs and combination preparations were associated with hepatotoxic injuries. But because of lack of objectivity, further researches must be conducted to yield more concrete results. Conclusions: yield more concrete results. Incidence figures are largely unknown, and in most cases a causal attribution is not established. The challenge for the future is to systematically research this area, educate all parties involved, and minimize patient risks.

• Korean Journal of Remote Sensing
• /
• v.34 no.3
• /
• pp.507-517
• /
• 2018

Aerosol optical depth (AOD) data retrieved by the Communication, Ocean and Meteorological Satellite (COMS) during 2011-2014 were compared with AOD measurements from 134 Aerosol Robotic Network (AERONET) sites over the East Asia. Overall, COMS and AERONET AODs were weakly correlated (R = 0.297). The agreement between COMS and AERONET AODs was improved when data from near Korean peninsula sites were selected (R = 0.475). Regression analysis results for each AERONET site are vary from R=0.026 at AOE_Baotou to 0.905 at DRAGON_Anmyeon. It was also shown that the bias in COMS AOD was not systematic with respect to effective radius, precipitable water, surface reflectance, and sun zenith angle. Together, these results suggest that COMS AOD measurements may be suitable for near Korea. Finally, the current results will help to improve the retrieval algorithm and vary when using alternative COMS AOD version in the future.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.17 no.2
• /
• pp.97-104
• /
• 1999

Digital elevation models(DEMs) represent an important data base for orthophoto generation The quality of a DEM depends on the geometrical accuracy of the original point or line data. This study analyzes the effects of grid space and scanning resolution in DEM creation with image matching method. The less standard deviation of DEM error was introduced when we adopted small grid space, but no effects in scanning resolution. Based on the bias error analysis of the DEM, we found that the error of a large scale of aerial photograph was bigger than that of a small scale case, and that such error mainly came from the closed area in large scale photographs. In order to reduce the closed area, the experiment has been conducted using multi scale and different overlap of aerial photo images. The result shows that the size of closed area and the shaded area has been dramatically decreased due to the adoption of multi scale aerial images instead of a couple of stereo images.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.12
• /
• pp.7613-7619
• /
• 2013

Background and Aims: Helicobacter pylori infection may be associated with an increased risk of colorectal carcinoma. However, as most studies on this subject were relatively small in size and differed at least partially in their designs, their results remain controversial. In this study, we aimed to carry out a meta-analysis to evaluate the potential association of H. pylori infection with colorectal adenoma and adenocarcinoma risk, covering all of the different testing methods. Methods: We conducted a search in PubMed, Medline, EBSCO, High Wire Press, OVID, and EMBASE covering all published papers up to March 2013. According to the established inclusion criteria, essential data were then extracted from the included studies and further analyzed by a systematic meta-analysis. Odds ratios were employed to evaluate the relationship between H. pylori infection and the risk of colorectal neoplasms. Results: Twenty-two studies were included, and the odds ratio for the association between H. pylori infection and colorectal cancer was 1.49 (95% confidence interval 1.30-1.72). No statistically significant heterogeneity was observed. Publication bias was ruled out. Conclusion: The pooled data suggest H. pylori infection indeed increases the risk of colorectal adenoma and adenocarcinoma.