• 천문학회보
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• 제35권1호
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• pp.29.1-29.1
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• 2010

We report three types of evolutions of EUV bright points (EBPs) which are characterized by their height variations. We analyzed three EBPs during their lifetimes observed by STEREO/SECCHI/EUVI and we obtained heights, sizes, and intensities. Moreover, we investigated their underlying magnetic bipoles observed by SOHO/MDI and we measured distances and fluxes of the two opposite fragments. We found three distinct changes in the heights of the EBPs: upward, downward, and flat. In the upward case, the EBP showed a small and dark structure first, and then changed to a large and bright loop. In the downward case, the EBP first appeared as a large and dark loop structure, and then evolved to a compact and bright loop system. Finally, in the flat case, the height and the size of the EBP didn't change significantly. We found that those EBPs were associated with three distinct contact types of their underlying magnetic fragments, emerging, cancelling, and shearing, respectively. In all cases, both flux emergences and flux cancellations were observed during the lifetimes of the BPs. The flux emergence was dominant in the initial phase and the flux cancellation was significant when the intensity reached its maximum. In addition, we found a remarkable correlation between the heights of the EBPs and the distance of the opposite magnetic fragments.

• 한국수산과학회지
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• 제24권6호
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• pp.428-436
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• 1991

영향성 대륙붕에서는 서로 반대 방향으로 진행하는 두 집합의 대륙붕파가 생성된다. 두 대륙붕이 충분히 떨어질 경우에는 두 집합의 대륙붕파는 독립된 대륙붕파가 되며 이 파들은 하나의 대륙붕 지형의 대륙붕파와 일치한다. 그러나 두 대륙붕의 간격이 Rossby Deformation Radius 보다 가까울 때는 두 집합의 대륙붕파는 두 대륙붕 지형에 영향을 받게 된다. 영향성 대륙붕에서도 대륙붕파는 북반구에서 해안선을 오른쪽에 두고 진행한다. 군속도(group velocity)는 장파인 경우에는 파의 진행방향과 같으나 단파인 경우에는 반대가 된다. 그러므로 각 대륙붕파는 어떤 중간의 파장에서 0인 군속도를 갖게 된다.

• 대한전자공학회논문지SD
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• 제43권12호
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• pp.74-80
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• 2006

본 논문에서는 위상 잡음 특성을 향상시킬 수 있는 전류보상 기법을 이용한 새로운 인상고정루프를 제안하였다. 제안된 위상고정루프는 주 전하펌프(MCP; Main Charge Pump)와 보조 전하점프(SCP; Sub Charge Pump)로 명명된 두 개의 전하펌프를 사용한다. 보조 전하펌프는 주 전하펌프 보다 작은 양의 전류를 반대방향으로 루프절터에 공급하여 루프필터의 전압 흔들림을 억제하였다. 이러한 전류보상 기법은 위상고정루프의 위상 잡음을 감소시켰다. 제안된 위상고정루프는 $0.35{\mu}m$ 3.3V CMOS 공정을 이용하여 제작되었다. 1MHz 오프셋에서 측정된 위상 잡음은 -103dBc/Hz로 기존의 위상고정루프에 비해 최소 3dBc/Hz의 위상 잡음 향상을 가져왔다.

• 천문학회보
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• 제36권2호
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• pp.99-99
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• 2011

A statistical study of coronal hole merging and splitting has been performed through Solar Cycle 23. The NOAA/SESC solar synoptic maps are examined to identify inarguably clear events of coronal hole merging and splitting. The numbers of merging events and splitting events are more or less comparable regardless of the phase in the solar cycle. The number of both events, however, definitely shows the phase dependence in the solar cycle. It apparently has a minimum at the solar minimum whereas its maximum is located in the declining phase of the sunspot activity, about a year after the second peak in Solar Cycle 23. There are more events of merging and splitting in the descending phase than in the ascending phase. Interestingly, no event is found at the local minimum between the two peaks of the sunspot activity. This trend can be compared with the variation of the average magnetic field strength and the radial field component in the solar wind through the solar cycle. In Ulysses observations, both of these quantities have a minimum at the solar minimum while their maximum is located in the descending phase, a while after the second peak of the sunspot activity. At the local minimum between the two peaks in the solar cycle, the field strength and the radial component both have a shallow local minimum or an inflection point. At the moment, the physical reason for these resembling tendencies is difficult to understand with existing theories. Seeing that merging and splitting of coronal holes are possible by passage of opposite polarity magnetic structures, we may suggest that the energizing activities in the solar surface such as motions of flux tubes are not exactly in phase with sunspot generation, but are more active some time after the sunspot maximum.

• Journal of Power Electronics
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• 제12권1호
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• pp.120-127
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• 2012

Fault diagnosis technique of electrical drives is becoming more and more important, since voltage fed converter system has become industrial standard in many applications. Many studies have been conducted an inverter fault diagnosis for induction motors. However, there are few researches about fault diagnosis of 3-phase ac/dc PWM (Pulse Width Modulation) converter compared to the dc/ ac inverter. The ac/dc converter is the opposite of dc/ac inverter at current flow. Also, inverter and converter have different current patterns under the same condition of IGBT (Insulated gate bipolar transistor) open switch fault. Therefore, it is difficult to apply intact diagnosis methods of inverter to the converter. This paper proposes modified fault detection methods for IGBT open switch fault in 3-phase ac/dc PWM converter by modifying established fault diagnostic methods for dc/ac inverters.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.197-203
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• 2001

A fusion protein, consisting of human epidermal growth factor as a recognition domain and human angiogenin as a toxin domain, can be used as a targeted therapeutic against breast cancer cells among others. The fusion protein was expressed as inclusion body in recombinant E. coli, and when the conventional, solution-phase refolding process was used the refolding yield was very low due to severe aggregation, probably due to the opposite surface charge due to vastly different pI values of each domain. Solid-phase refolding process exploiting ionic interactions between the solid matrix and the protein was tried, but the ionic binding yield was very low regardless of the resins and pH conditions used. To provide higher affinity toward the solid matrix, six lysine residues were tagged to the N -terminus of the hEGF domain When the cation exchange resins such as heparin- or CM-Sepharose were used as the matrix, the adsorption capacity increased 2.5-3 times and the subsequent refolding yield increased nearly IS times compared to the conventional process.

• 대한지역사회영양학회지
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• 제3권2호
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• pp.210-217
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• 1998

The purpose of this study was to examine changes in energy and macronutrient intakes during the premenstrual(days -10-1) and postmenstrual(days 5-14) phases. Thirty-two college female students recorded their food consumption and dietary patterns over 5 weeks from September 8 to October 12, 1997. Mean daily energy and macronutrient intakes and the percentage of energy intake from protein and carbohydrate were relatively consistent over the two menstrual cycle phases, but the energy intake from fat increased 1%(P<0.05)during the postmenstrual phase. Two different dietary patterns were identified by the shifts in energy intake between postmenstrual and premenstrual phases. Seventy five percent of subjects revealed a consistent pattern with the results of previous studies investigating food intake over the menstrual cycle, in which the premenstrual phase is associated with an increment in energy, carbohydrate, and protein intake. In contrast, energy, protein, and fat intakes increased during the postmenstrual phase in 25% of the subjects. We conclude that cyclical fluctuations in energy and macronutrient intakes occur in both postmenstrual and premenstrual dietary pattern groups across the two menstrual phased with the opposite directions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.41-44
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• 1999

Displacement current was generated in the pressure stimulus and light stimulus. Solution of azobenzene molecules (8A5H) have to character trans-to-cis. Pressure stimulus generate in the pressure and current. light stimulus generate in the displasement current. The Maxwell displacement current measuring technique has been applied for the investigation of azobenzene organic thin films under alternating photoirradiation with ultraviolet(360nm) and visible (450nm) light. The displacement current was generated due to the trans-to-cis photoisomerization by irradiation with ultraviolet light(λ$_1$=360 nm) Whereas the displacement current was generated in the opposite direction due to the cis-to-trans photoisomerization by irradiation with visible light(λ$_2$=450nm). As result, To show twice reaction certainly phase transition in pressure. A first range generated from 24$\AA$$^2$ to 29$\AA$$^2$and second range generated from 20$\AA$$^2$to 24$\AA$$^2$. Also, cetainfy stimulus apper low pressure and high pressure in photoirradiation. To see different every moment phase transition.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.238-240
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• 2017

동축 선로를 이용한 발룬은 쉬운 제작, 높은 동작 전력, 안정적인 동작으로 초고주파 회로에서 자주 이용된다. 하지만, 동축 선로 발룬은 동축 선로와 기판에 존재하는 마이크로스트립 선로와의 연결할 때에 발생하는 기생 리액턴스 성분과 동축 선로 자체가 가지는 인덕턴스와 케패시턴스 성분에 의해 정확한 발룬 동작 특성을 예상하기 어렵다. 본 논문에서는 역위상 특성을 가지는 동축 선로 발룬 두 출력 단자에서의 위상 특성을 측정하였다. 이를 바탕으로 보다 개선된 동축 선로 발룬 제작 가능성에 대해 살펴보려 한다.

• KSBB Journal
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• 제5권2호
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• pp.95-100
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• 1990

균주 K.fragilis에 의한 이눌린의 PEG/Dextran 수성 이상계 알콜발효실험에서 알콜발효특성, 알콜 및 이눌린의 분배특성에 미치는 PEG분자량. PEG농도, Dextran농도의 영향을 구명하여 보았다. Dextran농도 1내지 3wt%범위에서 에탄올 발효능과 에탄올 생산성은 PET분자량 증가에 따라 감소하였으며 균체수율과 균체생산성은 그 반대 경향을 나타내었다. PEG농도 6내지 10wt%범위에서 윗상에서의 에탄올 배수율은 아랫상의 Dextran농도가 증가할수록 감소하였다. 이눌린 분배계수는 PEG분자량 증가에 따라 미세하게 감소하였으며, PEG농도에 영향을 받는 이눌린 분배특성은 분배계수, 분배수율 및 분배비이였으며. Dectran농도 증가에 따라 분배계수와 아랫상에서의 이눌린 분배수율은 증가하는 반면 이눌린 분배비는 감소경향을 나타내었다.