• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.2
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• pp.43-46
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• 1975

In a chopper amplifier the input signal of the AC amplifier is a train of square-waves. In the rase of square-wave the operatiom of AC amplifier is much different from that of ordinary sinusoidal wave. In this paper for the purpose of contributing to the design of chopper amplifier destortions of waveforms in the amplifier were investigated. When the time constant of each stage is equal the waveform in each stave apppears as square wave whose top is exponentially decaying. And when each stave has different time constant the waveform in n-th stage is composed of n-square waves whose tops are exponentially decaying.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.701-712
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• 2013

The e-learning industry status survey statistic provides information about the actual conditions of supply and demand of the e-learning industries. NIPA (National IT Industry Promotion Agency) has published the annual report of the survey results since 2004. Due to the 9th version of the KSIC (Korean standard industrial classification) revised in 2008, a refinement of the sampling design for the survey becomes necessary, especially that for the business demand sector. This article, based on the 9th revision of the KSIC, constructs a stratification of the target population used for the e-learning industry status survey on the business demand sector. Classification of strata in the business population is based on the industrial type and employment scale of business. Under the stratified population, we design a sampling scheme by using the power allocation method that enables us to satisfy a target coefficient of variation of each industrial stratum. In order to secure an accurate survey results based on the proposed sampling design, we consider the problem of calculating the design weights, derivation of parameter estimators, and formulas of their standard errors.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.4
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• pp.227-239
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• 2011

Objectives: This study was performed to report the case of oriental medical treatment for the left lower limb monoplegia after herniated intervertebral disc(HIVD) operation at lumbar(L)-spine. Methods: A 38-year-old man who underwent lumbar HIVD operation at a hospital admitted with motor weakness of left lower limb, a little decreased left leg radiation pain and low back pain. We treated him by acupuncture, herbal medicine, bee venom injection moxibustion, cupping treatment physical therapy and measured with visual analogue scale(VAS), Oswestry disability index(ODI), Roland-Morris disability questionnaire(RMDO) and manual muscle test(MMT) from 8th February to 4th May 2011. Results: After treatment most symptoms decreased, VAS score changed from 10 to 3, ODI changed 71% to 37% RMDQ changed 13 to 8 and MMT changed from 3 to 5. Conclusions: Our study suggested that oriental medical treatments are significantly applicable to the monoplegia and pain after lumbar HIVD operation. And further studies ire required to identify underlying mechanism of the treatment.

• Journal of The Korean Association For Science Education
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• v.22 no.2
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• pp.267-275
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• 2002

The subject of this study were 7th grade three students in a school in Seoul, Korea. They discussed the inquiry problem to be investigated during summer vacation. We analysed the process of how the inquiry problem is revised and improved to more investigative one in the discussion. Student always discussed the method in the light of problem and the existence of the method of a problem affect the endurance of problem. The main subject of a problems are in everyday context, which is the object of critics in discussion. Student respond to the critics in many ways. Main types of reaction to the critics are two kinds. One is a person who change their views to the critics, the other is a person who kept their ideas.

• Convergence Security Journal
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• v.20 no.4
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• pp.113-123
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• 2020

The fourth industrial revolution can be called the hyper-connected-based intelligent revolution triggered by advanced information technology and intelligent technology, and the basis for implementing these technologies is 'data'. This study proposes a way to strategically use data in order to lead this intelligent revolution in the defense area. First of all, implications through analysis of domestic and international trends and prior research and current status of defense data management were analyzed, and four directions for development were presented. If the government composes conditions for building, releasing, sharing, distribution, and convergence of defense data considering the environment of national defense in the future, it is expected that it will serve as a foundation and a shortcut to be a digitalized strong military through smart defense innovation in the era of the fourth industrial revolution.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.35-43
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• 2022

It was to test the efficiency of essence containing scalp derived Leuconostoc mesenteroides extract on relieving hair loss and the possibility of the usage as the functional cosmetic's material. 41 subjects were classified as the control and test group and for 24 weeks, from Apr. 15th 2021 to Nov. 4th 2021, they were double blindness, contrast samples, single organs, and randomized human applicating tests were performed. The amount of hair had meaningful change (p<0.001) seen through phototricogram in 8,16,24 weeks each, and could tell the difference by researcher's bare eye after 24 weeks. Since there were meaningful changes (p<0.017) in subjective evaluation of the subject on after 8,16,24 weeks time, Essence which contains 1% of L. mesenteroides has efficiency on hair loss. Therefore, L. mesenteroides is expected to be used as various cosmetics to prevent hair loss.

• Journal of Society of Preventive Korean Medicine
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• v.26 no.3
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• pp.97-108
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• 2022

Objectives : The purpose of this study is to confirm the efficacy and safety of Gongjin-dan and Ssanghwatang for chronic fatigue. Methods : A total of 90 people, between 19 and 65 years old, will be recruited to participate in a randomized, double-blind, and placebo-controlled a clinical trial. Participants in the Gongjin-dan group will take one pill of Gongjin-dan along with three packs of placebo oral liquid Ssanghwa-tang per day for 4 weeks. Participants in the Ssanghwa-tang group will take three packages of liquid Ssanghwa-tang and one placebo Gongjindan pill per day for 4 weeks. In the placebo group, participants will take one pill of placebo Gongjin-dan and three packs of placebo liquid Ssanghwa-tang per day, for 4 weeks. Outcomes will be measured at the baseline, 4^th week, and 6^th week. The primary outcome is the change in the Fatigue Severity Scale (FSS). Secondary outcomes are the change of Multidimensional Fatigue Inventory-20 (MFI-20), Chalder Fatigue Scale (CFQ), Short-Form 36 Health Survey (SF-36), Korean Version of Schedule of Fatigue and Anergy/General Physician (SOFA/GP), Glucose, Lactate, Ammonia, Free Fatty Acid (FAA), d-ROMs&BAP, Selenium, and Cortisol. Results : This trial was approved by the institutional review board of Pusan National University Korean Medicine Hospital (registry number: PNUKHIRB 2021-10-005). Recruitment opened in November 2021 and is supposed to be completed by December 2022. Conclusions : This trial will provide clinical information to determine the efficacy and safety of Gongjindan and Ssanghwa-tang for chronic fatigue.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.23-30
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• 2023

This study was attempted to be used as basic data for efficient clinical practice education operation by identifying differences in program outcomes before and after integrated clinical practice of nursing students. Data collection was conducted before and after 6 weeks of integrated clinical practice for 38 nursing college students from July 19 to September 10, 2021 with a single group pre- and post-design. The collected data were analyzed by frequency, Wilcoxon sign rank, and Pearson correlation using SPSS/Win 23.0. After the integrated clinical practice, 1st program outcomes(Care integration)(Z=-4.63, p<.001), 2nd(Core practice)(Z=-3.99, p<.001), 6th(Critical thinking)(Z=-3.60, p<.001) and 11th(Research practice)(Z=-2.76, p=.005) increased significantly compared to before practice. Since integrated clinical practice was found to be an effective practice to improve program outcomes, it is suggested to actively utilize it as a strategy for improving program outcomes.

• Journal of Nutrition and Health
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• v.46 no.1
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• pp.50-60
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• 2013

The aims of this study were to estimate daily intake of macrominerals from beverages, liquid teas, and liquid coffees and to evaluate their potential health risks for Korean children and adolescents (1-to 19 years old). Assessment of dietary intake was conducted using the actual level of sodium, calcium, phosphorus, potassium, and magnesium in non-alcoholic beverages and (207 beverages, 19 liquid teas, and 24 liquid coffees) the food consumption amount drawn from "The Fourth Korea National Health and Nutrition Examination Survey (2007-2009)". To estimate the dietary intake of non-alcoholic beverages, 6,082 children and adolescents (Scenario I) were compared with 1,704 non-alcoholic beverage consumption subjects among them (Scenario II). Calculation of the estimated daily intake of macrominerals was based on point estimates and probabilistic estimates. The values of probabilistic macromineral intake, which is a Monte-Carlo approach considering probabilistic density functions of variables, were presented using the probabilistic model. The level of safety for macrominerals was evaluated by comparison with population nutrient intake goal (Goal, 2.0 g/day) for sodium, tolerable upper intake level (UL) for calcium (2,500 mg/day) and phosphorus (3,000-3,500 mg/day) set by the Korean Nutrition Society (Dietary Reference Intakes for Koreans, KDRI). For total children and adolescents (Scenario I), mean daily intake of sodium, calcium, phosphorus, potassium, and magnesium estimated by probabilistic estimates using Monte Carlo simulation was, respectively, 7.93, 10.92, 6.73, 23.41, and 1.11, and 95th percentile daily intake of those was, respectively, 28.02, 44.86, 27.43, 98.14, and 3.87 mg/day. For consumers-only (Scenario II), mean daily intake of sodium, calcium, phosphorus, potassium, and magnesium estimated by probabilistic estimates using Monte Carlo simulation was, respectively, 19.10, 25.77, 15.83, 56.56, and 2.86 mg/day, and 95th percentile daily intake of those was, respectively, 62.67, 101.95, 62.09, 227.92, and 8.67 mg/day. For Scenarios I II, sodium, calcium, and phosphorus did not have a mean an 95th percentile intake that met or exceeded the 5% of Goal and UL.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.479-484
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• 2004

Immunoinhibitory protein extracted from sonicated Treponema denticola have been shown to suppress cell cycle progression of human lymphocytes. To study in detail about the effect of this microorganism on the function of lymphocytes. we investigated the levels of Interleukin-2 (IL-2) and Interleukin-4 (IL-4) production by T lymphocytes before and after the addition of $12.5{\;}\mu\textrm{g}/ml$ T. denticola sonicated extracts. In this study. levels of IL-2 and IL-4 produced from T cells pretreated with sonicated extracts were evaluated by using the quantitative sandwich enzyme immunoassay technique. In response to phytohemagglutinin (PHA) stimulation. T cell produced increased levels of IL-2 and IL-4. However. the expressions of both cytokines were significantly inhibited when PHA activated-T cells were pre-exposed to sonicated T. denticola extracts (p < 0.05). These findings suggest that the T. denticola sonicated extracts induced-immunosuppression in Th1 and Th2 cell functions could be a part of the pathogenic mechanism of the endodontic failure associated with this microorganism.