• Journal of Advanced Marine Engineering and Technology
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• 제25권6호
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• pp.1308-1316
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• 2001

This paper described a numerical investigation performed to understand better the effects of flow parameters in an entrained flow combustor on the flow characteristics. The computational model was based on the gas phase Eulerian equations of mass, momentum and energy. The code was formulated with RNG $k-\varepsilon$ model for turbulent flow. The calculation parameters were the ratio of primary and secondary jet velocity and the height difference between primary and secondary jet As the secondary jet velocity increased, the upper recirculation 3one of the primary jet was strengthened. It was found that as the primary jet velocity increased, there was a critical jet Velocity at which the size of upper and lower recirculation zone was reversed.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2000년도 춘계학술대회 논문집(Proceeding of the KOSME 2000 Spring Annual Meeting)
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• pp.86-92
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• 2000

Two-phase flow in a combustion chamber is experimentally analyzed according to the five different conditions in the Reynolds number of $1.02{\times} 10^4$ As the height difference between the primary and secondary jets increases the secondary has a little effect on the primary. In the case of the same height difference the primary jet is affected as the velocity of secondary increases. The primary-jet flow field causes the particle concentration since the particle stagnation phenomena appear in the recirculation zone. The particle concentration is controlled by the velocity of secondary jet the height difference and the angle of primary jet in the test section.

• Journal of Electrical Engineering and Technology
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• 제5권4호
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• pp.538-544
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• 2010

This paper proposes an estimation algorithm for the separate primary and secondary leakage inductances of a three phase $Y-\Delta$ transformer using least squares method. The voltage equations from the primary and secondary windings are combined into a differential equation to estimate the separate primary and secondary leakage inductances in order to use the line current of the delta winding. Separate primary and secondary leakage inductances are obtained by applying least squares method to the differential equation. The performance of the proposed algorithm is validated under transient states, such as magnetic inrush and overexcitation, as well as in the steady state with various cut-off frequencies of low-pass filter. The proposed technique can accurately generate separate leakage inductances both in the steady and transient states.

• 대한한방부인과학회지
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• 제32권3호
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• pp.116-127
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• 2019

Objectives: The purpose of this study is to evaluate the effects of Gamitonggyung-tang on Primary Dysmenorrhea. Methods: We treated 33 cases of primary dysmenorrhea patients with Gamitonggyung-tang for three menstrual cycles. We estimated the effects by Visual Analog Scale (VAS), Menstrual Distress Questionnaire (MDQ) and checked amount of the analgesics taken during menstrual phase. Results: After treatment, the mean of VAS, MDQ Score and amount of the analgesics taken were decreased. Conclusions: This case shows that Gamitonggyung-tang is effective in treating primary dysmenorrhea patients.

• 천문학회보
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• 제41권1호
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• pp.77.4-78
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• 2016

Binary interactions may have significant impact on Pop III stellar evolution. Pop III single star evolution indicates that for primary masses less than $20M_{\odot}$, no significant binary mass transfer would occur before core helium exhaustion. We perform binary system evolution for various primary masses ($20M_{\odot}$ < $M_1$ < $60M_{\odot}$) and initial periods under same mass ratio $M_2/M_1=0.9$, and follow the evolution and mass transfer of the primary star. If binary mass transfer occurs during post main sequence, the primary star does not evolve into naked helium star and still contain significant hydrogen in the envelope. During the post mass transfer phase, the primary star evolves redward, and does not become sufficiently hot to enhance the number of ionizing photons, compared to the case of single star evolution for a given initial mass. This result implies that primary stars of massive Pop III binary systems would have little contribution to the reionization in the early universe. Given the large hydrogen content ($0.326-1.793M_{\odot}$), the primary stars that underwent stable mass transfers would explode as a Type IIb supernova, and it would be difficult for Pop III binary stars to produce Type Ib/c supernovae that look similar to those found in the local universe.

• 한국전기전자재료학회논문지
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• 제36권6호
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• pp.614-619
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• 2023

The fault current limiting characteristics of three-phase transformer type superconducting fault current limiter (SFCL), which consisted of three-phase primary and secondary windings wound on E-I iron core, one high-TC superconducting (HTSC) element connected with the secondary winding of one phase and another HTSC element connected in parallel with other two secondary windings of two phases, were analyzed. Unlike other three-phase transformer type SFCLs with three HTSC elements, three-phase transformer type SFCL using double quench has the merit to perform fault current limiting operation for three-phase ground faults with two HTSC elements. To verify its proper three-phase ground fault current limiting operation, three-phase ground faults such as single-line ground, double-line ground and triple-line ground faults were generated in three-phase simulated power system installed with three-phase transformer type SFCL using double quench. From analysis of its fault current limiting characteristics based on tested results, three-phase transformer type SFCL using double quench was shown to be effectively operated for all three-phase ground faults.

• 한국인터넷방송통신학회논문지
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• 제10권5호
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• pp.113-119
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• 2010

본 논문에서는 한 쌍의 1차 사용자 송 수신단(PT-PR)과 한 쌍의 2차 사용자 송 수신단(ST-SR)을 가지는 무선 인지 통신 시스템을 고려한다. 첫 번째 시간 슬롯(1 Phase)에서 1차 사용자 송신단(Primary Transmitter : PT)은 1차 사용자 수신단(Primary Receiver : PR), 2차 사용자 송신단(Secondary Transmitter : ST) 및 2차 사용자 수신단(Secondary Receiver : SR)에 자신의 신호 $x_p$를 브로드캐스트하며, 각각의 수신단(PR, ST, SR)에서는 수신된 신호를 복호한다. 두 번째 시간 슬롯(2 Phase)에서 ST는 수신 후 복호한 ${x_p}^{\prime}$와 자신이 전송하고자하는 신호 $x_s$를 결합하여 PR과 SR에 브로드캐스트하고, 각 수신단(PR, SR)에서는 수신한 신호를 복호한다. 이 때 PR은 첫 번째 시간 슬롯에 수신한 $x_p$와 두 번째 시간 슬롯에 수신한 $x_p+x_s$ 신호 중 $x_p$를 검출하여 최대 비 결합(Maximal Ratio Combining) 기법을 이용하여 결합한다. 이 때 PR에서는 다이버시티 이득을 얻을 수 있다. SR은 첫 번째 시간 슬롯에 수신한 $x_p$와 두 번째 시간 슬롯에 수신한 $x_p+x_s$신호를 가지고 선형결합을 통해 $x_s$를 얻는다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.467-470
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• 2006

Superconducting fault current(SFCLs) are expected to improve not only reliability but also stability of real power systems. The analysis on the single line-to-ground fault current of the integrated three phase flux-lock type SFCL, which consists of three flux-lock reactor wound on an iron core in each single phase and three YBCO thin films, was investigated in current limiting operating characteristics. We compared additive polarity winding with the subtractive one in the flux lock reactor. Its turns ratio each phase between the primary and the secondary coils is 63:42. When a single line-to-ground fault occurred in any phase, the peak value of line current in the fault phase of the additive polarity winding increased up to 31.44[A] during first-half cycle. On the other hand, the peak value in the subtractive polarity winding increased up to 81.77[A] under the same conditions. This is because the current flow between the primary and the secondary windings becomes to be additive or subtractive in each winding direction. We confirmed that the current limiting behavior in the additive polarity winding was more effective for a single-line-to ground fault.

• 지역사회간호학회지
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• 제26권4호
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• pp.390-397
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• 2015

Purpose: The purpose of this study was to explore practice-based evidence for health promotion in vulnerable populations with hypertension in primary health care settings. Methods: Two methodological procedures were adopted for this triangulation study. In the first phase, the sample was obtained from the computerized clinical data repository of a community nursing center. A total of 286 clients were assessed for hypertension as an actual circulation problem as coded in the Omaha System. In the second phase, a qualitative focus group was surveyed through semi-structured interviews conducted by nine advanced practice nurses who had been serving the hypertensive patients. Results: The community nurses provided essential primary healthcare services including health teaching guidance and counseling, and surveillance to vulnerable populations living in medically underserved community. There was a significant positive correlation between knowledge and behavior (r=.53, p<.01), between knowledge and health status (r=.40, p<.05), and between behavior and health status (r=.48, p<.01). Conclusion: This triangulation study encompassed not only quantitative findings from the computerized records of clients but also other information acquired from advanced practice nurses. This study contributes to understanding the importance of health promotion nursing interventions even with populations already diagnosed with chronic diseases such as hypertension.

• 한국인터넷방송통신학회논문지
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• 제15권1호
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• pp.111-116
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• 2015

본 논문은 인지 통신의 1차, 2차 시스템 사이에서 발생되는 협력 스펙트럼 공유 모델을 고려한다. 제시된 모델은 동상 신호로 표현되는 1차 사용자의 메시지가 존재할 때, 직교 위상 기반의 신호인 2차 사용자의 메시지가 존재하기 위한 단일 2차 송신기 ST의 배치에 대해 표현한다. 상호 간섭이 없는 순간적인 스펙트럼 공유로 가정하였으므로, 2차 사용자의 동작으로 인한 1차 사용자의 동작을 보호하는 것은 불필요하다. 또한 1차 시스템의 신호, 2차 시스템의 신호가 동상 및 직교 위상인 직교 차원에 위치하는 것을 기반으로 하기 때문에, 1차 시스템과 2차 시스템의 신호는 상호 간섭이 발생하지 않으며 2차 시스템 전원의 일부를 사용하여 1차 시스템의 신호를 강화시킬 수 있다.