• Journal of the Korean Professional Engineers Association
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• v.39 no.3 s.186
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• pp.32-35
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• 2006

The recent speculation fever in Kangnam have been cooled down by the August 31 heavy taxation tool for curbing speculators. Another March 30 real estate control equipped with high capital gains tax up to 50% was targeting reconstruction projects of dilapidated apartment complexes mostly inside of Kangnam area. The shortage of larger unit supply with its high demand results in price polarization problem. It makes higher price for larger units and less price for smaller units, and therefore higher priced home owners become richer and lower priced home owners become poorer. To avoid the polarization problem and anther probable price hikes in the near future, it may be suggested to supply quality homes by loosening the tight rules for the apartment reconstruction project, and thereby kangnam housing price stabilization can be achieved.

• Animal Bioscience
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• v.37 no.4_spc
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• pp.742-754
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• 2024

Asia is not only the primary region for global pig production but also the largest consumer of pork worldwide. Although the pig production in Asia has made great progress in the past, it still is confronted with numerous challenges. These challenges include: inadequate land and feed resources, a substantial number of small-scale pig farms, escalating pressure to ensure environmental conservation, control of devastating infectious diseases, as well as coping with high temperatures and high humidity. To solve these problems, important investments of human and financial capital are required to promote large-scale production systems, exploit alternative feed resources, implement precision feeding, and focus on preventive medicine and vaccines as alternatives to antibiotics, improve pig breeding, and increase manure recycling. Implementation of these techniques and management practices will facilitate development of more environmentally-friendly and economically sustainable pig production systems in Asia, ultimately providing consumers with healthy pork products around the world.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.43-54
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• 2017

This paper analyzes the performance of two three-leg inverters and a five-leg inverter and proposes the optimal operation conditions in applying the five-leg inverter for the train propulsion system. The five-leg inverter offers a saving of two switches compared with the standard two three-leg inverters and it is possible to control two three-phase motors independently by using a control board. All of these features lead to a potential reduction in capital cost and miniaturization of system. In this paper, first, the analysis of the existing motor control method and PWM method for two-traction motor drive of urban railway is implemented. Next, the operation principle and performance of five-leg inverter is introduced. Through the analysis, when it applies the same motor control method and the same PWM method for three-leg inverter and five-leg inverter, the characteristic of motor's speed and torque is compared.

• Journal of the Korean Society of Radiology
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• v.5 no.3
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• pp.155-159
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• 2011

The purposed of this study were measured the radiation exposure of patients and workers by generators, and the protection state for radiation facilities. The subject of the study by X-ray generators in university hospitals of capital area, we measured the maximum irradiation condition of 80 kVp, 200 mA, 0.1 second in the control entrance, control room window, entrance of radiography, adjacent site. The leakage dose per week was which the control entrance was 0.11 mR/week, control room window was 0.15 mR/week, entrance of radiography was 0.12 mR/week and adjacent site was 0.06 mR/week with X-ray unit the mean And the leakage mean dose was 0.11 mR/week. Diagnostic X-ray tubes must ensure that the leakage radiation in the maximum leakage dose in week emitted by the tube outside the useful beam does not exceed certain levels provided by standards.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.30.1-30.7
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• 2020

Background: Dental studies of precocious puberty have focused on examination of jaw and dentition growth. The aim of the study was to analyze the relationship between precocious puberty and maxillary dental developmental abnormalities (DDAs). Methods: This retrospective study was conducted on the Korean patients in whom dental panoramic and hand-wrist radiographs had been taken before they were 15 years of age. The maxillary DDAs were assessed as mesiodens, congenital missing teeth, peg-shape lateral incisors, or impacted teeth. The chronological ages of the control group members were within the normal range of the hand-wrist bone age. Others with a peak luteinizing hormone of ≥ 5 and < 5 IU/L were allocated to central precocious puberty (CPP) and peripheral precocious puberty (PPP), respectively. Results: Of the enrolled 270 patients, 195, 52, and 23 were allocated to the control, CPP, and PPP groups, respectively. The maxillary DDAs were significantly more prevalent in the CPP group than in the other groups. Among those with maxillary DDA, the mesiodens predominated. Age- and sex-adjusted multivariate analysis revealed maxillary DDA (odds ratio, 3.36; 95% CI, 1.60-7.05) and especially mesiodens (odds ratio, 5.52; CI, 2.29-13.28) to be significantly associated with CPP. Conclusions: Maxillary DDAs were significantly more prevalent in the CPP group than in the PPP or control groups. Among the many types of maxillary DDAs, mesiodens was significantly associated with CPP and may be considered a predictor of the development of CPP.

• Journal of radiological science and technology
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• v.35 no.2
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• pp.93-102
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• 2012

Thanks to the rapid increase of the interest in the quality control of the General X-ray systems, this research proposes the direction of the quality control through comparing and inspecting the actual condition of the respective quality control in the Clinic, the educational institution and the hospital. The subjects of the investigation are diagnostic radiation equipment's in the clinic, the educational institution and the hospital around the capital. A test of kVp, mR/mAs out put test and reproducibility of the exposure dose, half value layer, an accordance between the light field and the beam alignment test, and lastly reproducibility of the exposure time. Then the mean difference of the percentage, the CV (Coefficient of Variation, CV) and the attenuated curve which are respectively resulted from the above tests are computed. After that we have evaluated the values according to the regulations on the Diagnostic Radiation Equipment Safety Administration regulations. In the case of the clinic and the educational institution, there were 22 general X-ray devices. And 18.2% of the kVp test, 13.6% of the reproducibility of exposure dose test, 9.1% of the mR/mAs out put test, and 13.6% of the HVL (Half Value Layer) test appeared to be improper. In the case of the hospital, however, there were 28 devices. And 7.1% of the reproducibility of exposure dose, 7.1% of the difference in the light field/ beam alignment, and 7.1% of the reproducibility of the exposure time appeared to be improper. According to the investigation, the hospital's quality control condition is better than the condition in the clinic and the educational institution. The quality control condition of the general X-ray devices in the clinic is unsatisfactory compared to the hospital. Thus, it is considered that realizing the importance of the quality control is necessary.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.10
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• pp.4223-4228
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• 2015

Objective: To investigate the diagnostic value of the R-way colposcopic evaluation system (R-way system) in cervical cancer screening. Materials and Methods: Between August 2013 and August 2014, a total of 1,059 cases referred to colposcopy in Peking University First Hospital were studied using both the R-way system and conventional colposcopy. Our study evaluated and compared the diagnostic ability of the two methods in detecting high-grade lesions and cervical cancer (hereinafter called CIN2+). Evaluation indicators including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), Youden index and the area under the curve (AUC) of the receiver operating characteristic (ROC) were calculated. Results: The R-way system had a slightly lower specificity (94.5%) than conventional colposcopy (96.0%) for CIN2+ detection (P=0.181). However, the sensitivity (77.8%) was significantly higher than with the conventional colposcopic method (46.6%) (${\chi}^2=64.351$, P<0.001). In addition, the AUC of the ROC for CIN2+ detection using the R-way system (0.839) was larger than that with conventional colposcopy (0.731) (Z=4.348, P<0.001). If preliminary result had been drawn from cervical exfoliated cytology before colposcopy referral, combination of the R-way system with cytology could increase the sensitivity to 93.9% for CIN2+ detection (excluding ASCUS\LSIL), confirmed by multipoint biopsy or ECC. Conclusions: The diagnostic value of the R-way evaluation system is higher than that of conventional colposcopic evaluation in cervical cancer screening. Moreover, taking the ease of use and standardized quality control management into account, the R-way system is highly preferable.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.9
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• pp.932-940
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• 2011

This paper presents an integrated analysis of supply chain and financing decisions of multi-national corporation. We construct a model in which multiple currency storage units are installed to manage the currency flows associated with multi-national supply chain activities such as raw material procurement, process operation, inventory control, transportation and finished product sales. Core contribution of this study is to quantitatively investigate the influence of macroscopic economic factors such as exchange rates and taxes on operational decisions. The supply chain is modeled by the Process-Storage Network with recycle streams. The objective function of the optimization is minimizing the opportunity costs of annualized capital investments and currency/material inventories minus the benefit to stockholders interpreted by home currency. The major constraints of the optimization are that the material and currency storage units must not be depleted. A production and inventory analysis formulation, the periodic square wave (PSW) model, provides useful expressions for the upper/lower bounds and average levels of the currency and material inventory holdups. The expressions for the Kuhn-Tucker conditions of the optimization problem are reduced to a subproblem and analytical lot sizing equations. The procurement, production, transportation and financial transaction lot sizes can be determined by analytical expressions after the average flow rates are already known. We show that, when corporate income tax is taken into consideration, the optimal production lot and storage sizes are smaller than is the case when such factors are not considered typically by 20 %.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.6
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• pp.37-42
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• 2004

It is necessary for what just keep a living body balance be devoted to it being varied with acidity serious trouble, and constitution of a study person about the density (ph) change that an alkaline ion necessary for a living body is numerical to supply a human body with number alkali by PWM voltage control. Works in the water which included the calcium (Ca), kalium (K), magnesium (Mg), natrium (Na) back who is helpful for a human body, and there is Alkaline. It is done this alkaline electrolysis to ask in order to create a number, and minerals are gathered through isolated layer (isolated special layer) to a - electrode direction, and is created. of course, prominent derelicts gather, and the acidity capital is happened, and -ion of a chlorine (Cl), phosphorus(P), sulfur (S) back is usable unfavorably in water of different use to a + electrode direction. Microprocessor was used with a - pole and a + pole with a PWM(pulse width modulation) voltage in this electrolysis process, and four kinds of PWM voltages were implemented, and a voltage every ph density change tried to be considered. It is expected by getting exactly if number alkaline ion of ph density value necessary is done with setting value if PWM control is used thus.

• Journal of the Korean Geographical Society
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• v.31 no.1
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• pp.68-87
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• 1996

This paper investigates spatio-temporal changes in the international system of linkages among multinational corporate domestic decision-making centers and their overseas subsidiary centers for the period 1974-1991. During this period advances in information technologies and an ever increasing interdependent world economy have permitted the globalization of resource transfers, production techniques, service provision and financial transactions. Based on a network theory of internationalization, the study idenifies the dispersion of multinational control centers and the diversification of their linkage patterns. These tendencies are led by small and medium sized quaternary places as well as the rapid growth of service industries. Corporate headquarters cease to be tied together to big corporate and governmental centers but will disperse over time at global, national and regional level. Using information statistics, this paper confirms the dispersion patterns of capital flows and diversification of multinational control linkages. With an increasing trend toward a multicentric world system and the associated diecline of the global hegemony of a small number of largest cities, multinational control linkages should continue to disperse.