• 제목/요약/키워드: Tertiary current distribution

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A Three-Phase Four-Wire DSTATCOM for Power Quality Improvement

  • Singh, Bhim;Jayaprakash, P.;Kothari, D.P.
    • Journal of Power Electronics
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    • v.8 no.3
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    • pp.259-267
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    • 2008
  • Power quality improvement in a three-phase four-wire system is achieved using a new topology of DSTATCOM (distribution static compensator) consisting of a star/delta transformer with a tertiary winding and a three-leg VSC (voltage source converter). This new topology of DSTATCOM is proposed for power factor correction or voltage regulation along with harmonic elimination, load balancing and neutral current compensation. A tertiary winding is introduced in each phase for a delta connected secondary in addition to the star-star windings and this delta connected winding is responsible for neutral current compensation. The dynamic performance of the proposed DSTATCOM system is demonstrated using MATLAB with its Simulink and Power System Blockset (PSB) toolboxes under varying loads. The capacitor supported DC bus of the DSTATCOM is regulated to the reference voltage under varying loads.

A Study on the Deposit Uniformity and Profile of Cu Electroplated in Miniaturized, Laboratory-Scale Through Mask Plating Cell for Printed Circuit Board (PCBs) Fabrication

  • Cho, Sung Ki;Kim, Jae Jeong
    • Korean Chemical Engineering Research
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    • v.54 no.1
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    • pp.108-113
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    • 2016
  • A miniaturized lab-scale Cu plating cell for the metallization of electronic devices was fabricated and its deposit uniformity and profile were investigated. The plating cell was composed of a polypropylene bath, an electrolyte ejection nozzle which is connected to a circulation pump. In deposit uniformity evaluation, thicker deposit was found on the bottom and sides of substrate, indicating the spatial variation of deposit thickness was governed by the tertiary current distribution which is related to $Cu^{2+}$ transport. The surface morphology of Cu deposit inside photo-resist pattern was controlled by organic additives in the electrolyte as it led to the flatter top surface compared to convex surface which was observed in the deposit grown without organic additives.

Factors Affecting the Distribution of Practicing Nurses (임상간호사 분포에 영향을 미치는 요인)

  • Euntae Park;Jinhyun Kim
    • Health Policy and Management
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    • v.34 no.1
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    • pp.94-102
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    • 2024
  • Background: There is controversy surrounding the claim that current nursing workforce policies exacerbate the geographic imbalance of nurses in Korea, but very few studies have confirmed this assertion. Therefore, this study aimed to identify factors influencing the distribution of nurses at the regional level, including variables related to nursing workforce policies. Methods: This study analyzed the distribution of 225,462 practicing nurses across 250 regions in Korea as of 2020. National statistics were collected for these 250 regions, and regression analysis was conducted. Results: Factors influencing the distribution of practicing nurses included the number of annual inpatient days, integrated nursing care service beds, public healthcare institutions, tertiary hospitals, and general hospitals. Additionally, the number of nursing graduates and healthcare institutions with nurse staffing grade 1 and 2 had an impact on nurse distribution in non-capital regions. Conclusion: To prevent exacerbating the geographic imbalance of nurses, careful decisions should be made regarding the expansion of integrated nursing care service beds. Furthermore, it is necessary to increase the number of nursing students in non-capital regions and prioritize the improvement of wages and working conditions for nurses in those areas.

Development of a New Modeling Technique to Simulate 3-dimensional Electroplating System Considering the Effects of Fluid Flow

  • Lim, Kyung-Hwan;Lee, Minsu;Yim, Tai Hong;Seo, Seok;Yi, Kyung-Woo
    • Journal of Electrochemical Science and Technology
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    • v.10 no.4
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    • pp.408-415
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    • 2019
  • Electroplating is a widely used surface treatment method in the manufacturing process of electronic parts and uniformity of the electrodeposition thickness is very crucial for these applications. Since many variables including fluid flow influence the uniformity of the film, it is difficult to conduct efficient research only by experiments. So many studies using simulation have been carried out. However, the most popular simulation technique, which calculates secondary current distribution, has a limitation on the considering the effects of fluid flow on the deposition behavior. And modified method, which is calculating a tertiary current distribution, is limited to a two-dimensional study of simple shapes because of the massive computational load. In the present study, we propose a new electroplating simulation method that can be applied to complex shapes considering the effect of flow. This new model calculates the electroplating process with three steps. First, the thickness of boundary layers on the surface of the cathode plane and velocity magnitudes at the positions are calculated from the simulation of fluid flow. Next, polarization curves of different velocities are obtained by calculations or experiments. Finally, both results are incorporated into the electroplating simulation program as boundary conditions at the cathode plane. The results of the model showed good agreements with the experimental results, and the effects of fluid flow of electrolytes on the uniformity of deposition thickness was quantitatively predicted.

An Integrated Approach to Linking Job Love with Contextual Factors and Performance: An Empirical Study from Pakistan

  • BIBI, Naila;SAEED, Bilal Bin;AFRIDI, Muhammad Asim
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.5
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    • pp.157-169
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    • 2022
  • Job love is an emerging phenomenon, which is the utmost approach to fulfilling employees' and organizations' mutual interests, especially performance. The current study aims to define and extend the existing proposed construct of "loving one's job" as job love. It provides a novel theoretical multi-level framework of job love, contextual factors, and performance principled on the attraction-selection-attrition framework and social exchange theory through an integrated approach. This study collected cross-sectional data through a questionnaire from 332 nurses across eight tertiary hospitals in Khyber Pakhtunkhwa, Pakistan. The findings are based on the structural equation modeling technique (SEM) at multi-levels. The results show significant relationships between job love, contextual factors, and performance at the individual and organization levels. There are some insignificant relationships between the variables at the cross-level. Job love plays a key role for both employees and organizations. It facilitates the individuals in the recruitment process to select the job they love, be a good fit, and stay committed to that particular job and organization. This phenomenon allows people to pursue their common interests. Job love assists firms in developing human resource capacity utilization plans that satisfy the needed requirements.

Metastatic Bone Disease as Seen in Our Clinical Practice - Experience at a Tertiary Care Cancer Center in Pakistan

  • Qureshi, Asim;Shams, Usman;Akhter, Azra;Riaz, Sabiha
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.9
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    • pp.4369-4371
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    • 2012
  • Aim: Metastatic tumor of bone is the most common malignancy involving bone and is an important predictor of prognosis in advanced cancers. The prognosis depends upon the primary site of origin and the extent of disease. In current study, we present the pattern and distribution of metastatic bone disease seen in the leading cancer care center of Pakistan, Shaukat Khanum Cancer Hospital & Research Center (SKMCH & RC), Lahore. Materials & Methods: All cases of bony metastatic disease were included that presented in the Pathology Department, from Jan 2005 to July 2011. Patients of all ages and both sexes were included. Primary bone tumors, lymphomas, sarcomas and other malignancies were excluded. The data were recorded and analyzed with SPSS 16.0. Results: A total of 146 cases of metastatic bone disease were included in the study. Out of the total cases, 79 were male and 67 were female. Age range 25-82 years (median 52). Hip bone was the most frequent bone involved, with femur and vertebrae as second and third in the list. The commonest bone involved in males was vertebrae with 23 cases and in females was hip bone with 22 cases. Regarding primary site, cancers of breast, prostate and gastrointestinal tract were at the top of the list with prostate and breast being the most frequent primary sites of metastasis in males and females respectively. Conclusion: Bone metastasis is an important entity to consider in the differential diagnosis whenever a bony tumor especially carcinoma present in older age. Our data are comparable with international findings and the literature available regarding the site and distribution of skeletal metastatic lesions. A slight deviation noted was more common bony metastatic lesions with ovarian primaries in females and gastrointestinal tract cancers in males in our study.

Discussions on the Distribution and Genesis of Mountain Ranges in the Korean Peninsular (I) : The Identification Mountain Ranges using a DEM and Reconsideration of Current Issues on Mountain Range Maps (한국 산맥론(I) : DEM을 이용한 산맥의 확인과 현행 산맥도의 문제점 및 대안의 모색)

  • Park Soo Jin;SON ILL
    • Journal of the Korean Geographical Society
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    • v.40 no.1 s.106
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    • pp.126-152
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    • 2005
  • In recent years, there are some confusions related to the definition and existence of mountain ranges, which have been described in current geography text books. We contend that these confusions came from the lack of understanding on the geomorphological processes that form the mountain system in Korea. This research attempts to clarify the definition of mountain ranges and offer geological and geomorphological explanations about the formation of them. Based on the analyses of the social and cultural causes underlying the recent debates on the existence of mountain ranges, we tried to identify the relationships among the definition of mountain ranges, geological structure of Korea, and the forming processes of mountain ranges. The current and past mountain range maps were compared with geological structures, geological maps, surface curvature, and hill shade maps. The latter two maps were derived from a Digital Elevation Model of the Korean Peninsular. The results show that we are able to prove the existence of most mountain ranges, which provides a useful framework to understand the geological evolution of Korean peninsular and formation of mountainous landscape of Korea. In terms of their morphological continuity and genesis, however, we identified five different categories of mountain ranges: 1) Uplift mountain ranges(Hamkyeong Sanmaek, Nangrim Sanmaek, Taebaek Sanmaek), which were formed by the uplift processes of the Korean Peninsular during the Tertiary; 2) Falut mountain ranges(Macheonryeong Sanmaek, Sobaek Sanmaek, Buksubaek Sanmaek), whirh were directly related to the uplift processes of the Korean Peninsular during the Tertiary; 3) Trust mountain ranges(Jekyouryeong Sanmaek, Kwangju Sanmaek, Charyeong Sanmaek, Noryeong Sanmaek), which were formed by the intrusion of granite and consequent orogenic processes during the Mesozoic era; 4) Drainage divide type mountain ranges, which were formed by the erosion processes after the uplift of Korean Peninsular; 5) Cross-drainage basin type mountain ranges (Kangnam Sanmaek, Eunjin Sanmaek, Myelak sanmaek), which were also formed by the erosion processes, but the mountain ranges cross several drainage basins as connecting mountains laterally We believe that the current social confusions related to the existence of mountain ranges has partly been caused by the vague definition of mountain ranges and the diversity of the forming processes. In order to overcome theses confusions, it is necessary to characterize the types of them according the genesis, the purpose of usages and also the scale of maps which will explains the mountain systems. It is also necessary to provide appropriate educational materials to increase the general public's awareness and understanding of geomorphological processes.

The Palaeoenvironmental Changes and Macromammal Evolution during the Pleistocene in East Asia (동아시아의 제4기 자연환경의 변화와 젖먹이근동물의 제4기적 진화)

  • Sun Joo, Park
    • The Korean Journal of Quaternary Research
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    • v.2 no.1
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    • pp.51-85
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    • 1988
  • The understanding of the faunal sequence and palaeoenvironment of East Asia since the Late Tertiary depends mainly on the knowledge of Chinese fauna and its environmental changes. The recent Chinese researches including geology, geomorphology, climats fluctuation and loess distribution of this area have provided that the rapid uplifting of Himalayas and Qinghai/Xizang Plateau since the Lower Pleistocene was a main selective factor for the process of environmental changes in this vast territory. Although different concepts of the Plio-Pleistocene boundary have been provided, its boundary can not exceed over 2 mya. Instead of the traditional zoogeographical dicthomy in China, faunal compositions of Pleistocene are divided into three faunal zones. The knowledge of macrofaunal evolution in China are useful to understand the palaeoecology of East Asia. Palaeoenvironment of Korea during the Pleistocene Period can be reconstructed by using the analogy of the current Chinese studies.

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Analysis on the Accessibility of the Primary Medical Facilities in Jinju City (진주시 1차 의료시설의 접근성 분석)

  • Kim, Mi Song;Won, Tae Hong;Yoo, Hwan Hee
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.3
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    • pp.49-55
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    • 2015
  • Current medical delivery system in Korea has been distinguished into three types; primary medical facilities, secondary facilities, and tertiary facilities since 1989. This system prevents the waste of medical resources along with the maintenance of balance according to the medical treatment subjects. However, it is inevitable that the imbalance of the medical services among regions has been generated due to the concentration of the medical facilities on large cities. In this regard, this study attempted to evaluate the quality of the primary medical services, emphasizing accessibility and convenience targeting Jinju city, a small and medium-sized city, based on the distribution characteristics of the space. The study results show that cohesion index about the spatial distribution of the primary care facilities was 0~0.25. It conducted a correlation analysis between the location of the hospitals and users, based on the study results. Finally, it is demonstrated the correlation between the location of the hospitals and users tended to be low, while, the cohesion of the Oriental medicine clinics was high in other treatment subjects, and the accessibility to the Oriental medicine clinics was the highest because most Oriental medicine clinics were distributed to the places where users were many. However, on account that the locations of the medical facilities and users were varied in other treatment subjects except for the Oriental medicine clinics, problems were generated in terms of the accessibility. Therefore, it is judged that the preparation of the measures to improve the selection of lots in consideration of users, who use the primary medical services, is required.

Current Status of MRI Distribution, Prevailing Charges and Analysis of Its Performance (MRI 분포와 관행수가 현황 및 촬영실적 분석)

  • 문옥륜;장원기;이상이;김철웅;최경혜
    • Health Policy and Management
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    • v.8 no.1
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    • pp.155-182
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    • 1998
  • There exists a remarkable differences in use of MRI scanning among income classes. The poor can hardly utilize it. This is because, among high cost technnologies, MRI is the only equipment not covered under health insurance benefits in Korea. This study was designed 1) to reveal the status of nation-wide MRI installation, customary charges and per unit annual scanning performance, and 2) to analyse factors influencing the above variables. The data for this study came from "MRI Prevalence Survey" conducted by the National Federation of Medcial Insurance(NFMI) in 1997, and were analyzed through SAS packages for T-test, analysis of variance and stepwise multiple regression. Data were collected from 188 hospitals equipped with MRI scanners. Major findings are summarized as follows : The number of MRI scanners has increased from 69 in 994 to 158 in 1996(2.3 times) while per unit annual scanning performance has risen by 11.2% from 2,173 cases in 1994 to 2,417 cases in 1996. Such a rapid increase was made possible mainly due to the inclusion of CT scanning under the health insurance benefit package. The customary charges for MRI scanning with or without contrast media, on average, amounted to 484,000 Won and 402,000 Won, respectively, with the percentile increase of 17.8% and 8.1% each during the same time. Korea ranks the third worldwidely in terms of number of MRI installations, 4.8 scanners per one million persons, only next to Japan and United States. Geographical variation of MRI, however, was rather high, 7.91 unit, in Cheju area compared to 1.82 in Kyongnam area. Variations of customary charges of MRI scanning can be explained as much as by 44.8% by both the total amount of claims to NFMI and geographical variable. The charges were more likely to be higher in metropolitan areas like Seoul and in hospitals with a bigger amount of claims. While those of per unit annual scanning performance can be explained as much as by 30.7% by both MRI installation cost and level of MRI-installed organizations. Per capital scannig performance was higher in tertiary hospitals and hospitals equipped with more expensive scanners than hospitals with less expensive scanners. Two measures are called for the remedying the existing excessive abundance in MRI units in korea : One is to set a ceiling of MRI units in an area like a province or a metropolitan district. The other is to establish a committee on introduction of high cost technologies for reviewing its effective use.ctive use.

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