• Journal of the Korean association of regional geographers
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• v.9 no.1
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• pp.86-96
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• 2003

The purpose of this paper is to explore the relationship between central city and suburban areas. In particular, we examine the relationship of construction activities in suburban areas with construction activities in central city. That is because if the construction activities in central city are correlated with those in suburban areas, the economic trends in those two parts would become interdependent. The construction permit data in 114 Metropolitan Statistical Areas (MSAs) for the past 11 years are used as a central explanatory variable of influencing the relationship, as construction permits issued would reflect population growth, economic growth and housing price in certain area. The main findings of our analysis are as follows. First, MSAs classified as showing high population growth has higher correlation between central city and suburban area than MSAs showing low population growth rate except for only office construction. However, there is little difference in correlation characteristic by the size of MSA Second, most of the MSAs show little causality between the central city and suburban area in lagged situation. Therefore, it is hard to say that the past trend of construction activity in central city reflects in direct the future trend of construction activities in suburban area.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.06a
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• pp.39-50
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• 1995

The membrane processes that are commonly uscd in water and wastewater treatment are reverse osmosis (Ro), ultrafiltration (UF) and microfiltration (MF), which utilize pressure differentials. There is also nano-filtration (NF), or low-pressure reverse osmosis, which is positioned midway between conventional reverse osmosis and ultrafiltration. Reverse osmosis membranes reject dissolved ions, while ultrafiltration can be used to reject relatively larger molecules, such as protein, polysacchalides and so on. Microfiltration is capable of eliminating particles at submicron level. This paper summarizes the characteristics of MSAS process first, as it is the main membrane process applied to wastewater treatment. Two successful examples of the applications, the cases of individual building reuse system and nightsoil treatment, are then shown. The latest trend of new membrane applications, i.e., immersed-type MSAS is also introduced.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.171-176
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• 2016

Background: Much has been done to examine the psychological impact of cancer treatment, but it remains unclear to what extent anxiety and depression is related to symptom prevalence. The present study concerned the characteristics and frequency of distress as related to symptom prevalence in cancer patients undergoing chemotherapy in Malaysia. Materials and Methods: Participants were 303 consecutive adult cancer patients undergoing chemotherapy in an academic medical center. The short form Memorial Symptom Assessment Scale (MSAS-SF), which covers three domains of symptoms (global distress, physical- and psychological symptoms) was used to cross-sectionally measure symptom frequency and associated distress via self-reporting. One-way ANOVA and t-tests were used to test mean differences among MSAS-SF subscale scores. Results: Complete data were available for 303 patients. The mean number of symptoms was 14.5. The five most prevalent were fatigue, dry mouth, hair loss, drowsiness and lack of appetite. Overall, symptom burden and frequency were higher than in other published MSAS-SF studies. Higher symptom frequency was also found to be significantly related to greater distress in cancer patients undergoing chemotherapy. Conclusions: Patients undergoing chemotherapy suffer from multiple physical and psychological symptoms. Better symptom control or palliative care is needed. Greater frequency of reported symptoms may also indicate a subconscious bid by patients for care and reassurance - thus tailored intervention to manage distress should be offered.

• Earthquakes and Structures
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• v.24 no.4
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• pp.303-316
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• 2023

Rapid post-earthquake damage estimation of subway stations is particularly necessary to improve short-term crisis management and safety measures of urban subway systems after a destructive earthquake. The conventional Performance-Based Earthquake Engineering (PBEE) framework with constant earthquake occurrence rate is invalid to estimate the aftershock risk because of the time-varying rate of aftershocks and the uncertainty of mainshock-damaged state before the occurrence of aftershocks. This study presents a time-varying probabilistic seismic risk assessment framework for underground structures considering mainshock and aftershock hazards. A discrete non-omogeneous Markov process is adopted to quantify the time-varying nature of aftershock hazard and the uncertainties of structural damage states following mainshock. The time-varying seismic risk of a typical rectangular frame subway station is assessed under mainshock-only (MS) hazard and mainshock-aftershock (MSAS) hazard. The results show that the probabilities of exceeding same limit states over the service life under MSAS hazard are larger than the values under MS hazard. For the same probability of exceedance, the higher response demands are found when aftershocks are considered. As the severity of damage state for the station structure increases, the difference of the probability of exceedance increases when aftershocks are considered. PSDR=1.0% is used as the collapse prevention performance criteria for the subway station is reasonable for both the MS hazard and MSAS hazard. However, if the effect of aftershock hazard is neglected, it can significantly underestimate the response demands and the uncertainties of potential damage states for the subway station over the service life.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.1
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• pp.25-30
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• 2014

Differential Global Positioning System-Correction Projection (DGPS-CP) algorithm, which has been suggested as a method of correcting pre-calculated position error by projecting range-domain correction to positional domain, is a method to improve the accuracy performance of a low price GPS receiver to 1 to 3 m, which is equivalent to that of DGPS, just by using a software program without changing the hardware. However, when DGPS-CP algorithm is actually realized, the error is not completely eliminated in a case where a reference station does not provide correction of some satellites among the visible satellites used in user positioning. In this study, the problem of decreased performance due to the difference in visible satellites between a user and a reference station was solved by applying the Multifunctional Transport Satellites (MTSAT) based Augmentation System (MASA) correction to DGPS-CP, instead of local DGPS correction, by using the Satellite Based Augmentation System (SBAS) operated in Japan. The experimental results showed that the accuracy was improved by 25 cm in the horizontal root mean square (RMS) and by 20 cm in the vertical RMS in comparison to that of the conventional DGPS-CP.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.178-186
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• 2009

SBAS(Satellite Based Augmentation System) provides GNSS satellite orbit and clock corrections for positioning accuracy improvement of GNSS users. In this paper, the accuracy of SBAS satellite orbit and clock corrections were analyzed by comparing with the IGS(International GNSS Service) precise ephemeris. The GPS antenna phase center offsets and the P1-C1 bias are considered for the analysis. The correction data of the US WAAS and the Japanese MSAS were analyzed. The analysis results showed that the SBAS satellite orbit and clock corrections are highly correlated. The correction data accuracy depends on the SBAS ground network size and orbit trajectories.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2768-2774
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• 2011

In this paper, we investigate the methods to improve the position accuracy using DGNSS(Differential Global Navigation Satellite System). Then we configure the real-time DGNSS environment with use of GPS and MSAS as SBAS(Satellite Based Augmentation System) currently being in service by Japan. And we verify the improvement of position accuracy and the continuity of GPS correction data through the realtime DGNSS test in Joongang line, Kyungbu line, Honam line.

• Journal of the Korean Home Economics Association
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• v.34 no.4
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• pp.119-131
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• 1996

The relationship of maternal separation anxiety, availability of support system and child gender to initial preschool adjustment was examined. Data were collected on 72 middle-class Korean children(35 boys, 37 girls) between the ages of 31 months and 60 months who were entering preschool. Subjects were from intact families, all with non-working mothers. Mothers completed the Maternal Separation Anxiety Scale(MSAS) and indicated the number of extended family members in the home as an index of social support. Classroom teachers completed the Preschool Behavior Questionnaire (PBQ) for each child after the first 2 weeks and again after 6 weeks of school. Each child was observed by the research team during the first 2 weeks of school and again after the 6th-week using the Child Observation System (COS). Applying the COS observed behavior was classified as being in the dependent, neutral, or active mode. All instruments were culturally relevant as validated by Korean experts. Maternal Separation Anxiety was a significant predictor for girls only, accounting for 11% of initial COS variance (p=＜.05). In contrast, social support was a significant predictor for boys only, accounting for 28% of initial PBQ variance when entered after MSAS(p=.005). A significant difference between initial and 6th-week adjustment was obtained in the expected direction on the COS with behavior improving with time (t=-4.06, p=.001). Although a significant difference between initial and 6th-week PBQ adjustment was also obtained (t=-3.63, p=.001), it was not in the direction expected, problematic behavior were found to increase with time. Cultural and developmental factors help explain the findings. Given the patrilineal social system in Korea, boys are highly preferred over girls. Thus the at-home support system, comprised primarily of grandparents, may have a significant influence on school adjustment particularly of first-born sons. In contrast, since girls are viewed as fragile and vulnerable, mothers may express greater separation anxiety about girls. Finally, as would be expected, older children may be able to develop coping skills more readily than younger ones, as child adjustment on the COS significanlty improved over the 6-week period.

• Electronics and Telecommunications Trends
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• v.29 no.3
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• pp.74-85
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• 2014

위성기반보정시스템(SBAS: Satellite Based Augmentation System)은 GPS(Global Positioning System) 항법위성 제공 신호에 각종 요인으로 인한 오차 등의 발생이 수반되므로 GPS 신호감시 및 제공 메시지 사용여부 등을 위한 무결성기능, 각종 오차 등을 차등적 보정에 의한 정확도 향상 기능, 항법신호 가용성 및 연속성을 위한 레인징 신호제공 기능 등을 통해 항공기 안전운항에 사용될 수 있도록 한 시스템이다. 본 시스템은 국제민간항공기구(ICAO: International Civilian Aviation Organization)가 국제표준으로 정해진 상태로 단계별로 정밀한 항법서비스를 제공한다. 현재 미국 WAAS(Wide Area Augmentation System), 유럽 EGNOS(European Geostationary Navigation Overlay System), 일본 MSAS (MTSAT Satellite Based Augmentation System)는 운용 중이고 우리나라도 한국형 SBAS 시스템을 개발키로 한 바, 본고에서 국내외 SBAS 시스템에 대해 개발동향을 살펴보고자 한다.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.401-404
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• 2001

We designed and fabricated symmetrical partially shorted MSAs for 850 MHz band on various Copper-clad Laminates substrates, where the width of the radiation patch is identical with that of the ground plane and the radiation patch is partially shorted to the ground plane. The resonant frequency, return loss and input impedance due to the permittivity(2.5, 3.5, 10.0) and thickness(0.76~1.57 mm, 6 types) were measured by reducing the PSW (Partially Shorted Width) to 0 mm. As a result, good characterized antennas with average 11% reduced resonant length and return loss 7.288~29.445 dB were obtained when the total PSW was in the range of 70% of radiated patch width, compared to the conventional λ/4 MSA.