• Journal of the Optical Society of Korea
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• 제12권4호
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• pp.326-336
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• 2008

A WDM-PON has been considered as an ultimate solution for access networks. However, there were many technical and practical issues for commercial deployment. These issues were solved with wavelength locked F-P LD and the WDM-PONs employing this optical source were commercialized. These WDM-PON systems have been deployed in Korea, Europe, and US. We reviewed wavelength locking technology and WDM-PON achievements. When we inject spectrum sliced broadband light into an F-P LD, the multimode output is changed to a quasi single mode. Then, we can use the single mode light for WDM signal transmission. The broad spectral gain of the semiconductor gain medium enables a color-free operation of WDM-PON, i.e., an identical ONT can be used for each user. The wavelength locking properties depend on many parameters, especially alignment of injection wavelength to a lasing mode, passband profile of AWG and front facet reflectivity of F-P LD. However, these dependencies can be reduced by proper design of the laser and the injection bandwidth. Thus, WDM-PON systems have been achieved with color-free operation.

• BMB Reports
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• 제55권7호
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• pp.305-315
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• 2022

Transposable elements (TEs) are DNA sequences capable of mobilization from one location to another in the genome. Since the discovery of 'Dissociation (Dc) locus' by Barbara McClintock in maize (1), mounting evidence in the era of genomics indicates that a significant fraction of most eukaryotic genomes is composed of TE sequences, involving in various aspects of biological processes such as development, physiology, diseases and evolution. Although technical advances in genomics have discovered numerous functional impacts of TE across species, our understanding of TEs is still ongoing process due to challenges resulted from complexity and abundance of TEs in the genome. In this mini-review, we briefly summarize biology of TEs and their impacts on the host genome, emphasizing importance of understanding TE landscape in the genome. Then, we introduce recent endeavors especially in vivo retrotransposition assays and long read sequencing technology for identifying de novo insertions/TE polymorphism, which will broaden our knowledge of extraordinary relationship between genomic cohabitants and their host.

• 대한소아치과학회지
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• 제46권2호
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• pp.219-225
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• 2019

이 연구의 목적은 과잉치 치수 유래 줄기세포의 계대 배양 속도에 대한 상아모세포 연관 유전자의 발현을 비교하는 것이다. 줄기세포는 다른 여러 형태의 세포로 분화할 수 있는 미 분화된 세포이다. 이는 환경이나 특정 자극에 의해 세포 분열이 일어나며 근육이나 골 같은 특정 장기의 조직으로 분화할 수 있다. 20명의 어린이에서 발거한 과잉치에서 과잉치 치수 유래 줄기세포가 얻어졌다. 10계대까지 배양하는 동안 가장 빠른 속도로 계대 배양된 세포와 가장 느린 속도로 계대 배양된 세포 각 3계대와 10계대 세포를 얻어 실험을 진행하였다. 각 세포는 분화제를 처리한 군과 처리하지 않은 군으로 나누었다. 이 실험에서 발현도를 살펴본 유전자는 Osteonectin (ONT), Osteocalcin (OCN), Alkaline Phosphatase (ALP), Dentin matrix acidic phosphoprotein 1 (DMP-1), Dentin sialophosphoprotein (DSPP)이다. 분화가 된 세포가 전반적으로 더 높은 유전자 발현도를 보였으며, 미분화 세포는 10계대에서, 분화된 세포는 3계대에서 더 높은 유전자 발현도를 보였다. 빠른 계대 배양 속도를 보인 세포가 OCN과 DSPP를 제외하고 상대적으로 더 낮은 유전자 발현도를 보였다.

• Journal of Acupuncture Research
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• 제18권4호
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• pp.143-151
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• 2001

Objective : This study was undertaken to determine whether Scutellaria balicalensis Georgi (SbG) extract exerts the protective effect against oxidant-induced alterations in organic cation transport in the renal proximal tubule. Methods : Organic cation transport was estimated by examining alterations in tetraethylammon - ium(TEA) uptake in rabbit renal cortical slices. The slices were treated with 0.2 mM tBHP for 60 min at $37^{\circ}C$. tBHP caused an inhibition in TEA uptake by renal cortical slices. Such an effect was accompanied by depressed Na+-K+-ATPase activity and ATP depletion. tBHP also induced a significant increase in LDH release. Results : SbG prevented tBHP-induced inhibition of TEA uptake in a dose-dependent manner at the concentration ranges of 0.05-0.1%. tBHP-induced inhibition of Na+-K+-ATPase activity and ATP depletion were significantly prevented by 0.05% SbG. tBHP-induced LDH release also was blocked by SbG. tBHP caused a significant increase in lipid peroxidation and its effect was prevented by SbG. Conclusion : These results suggest that SbG prevents oxidant-induced alterations in organic cation transport in rabbit renal cortical slices. Such protective effects of SbG may be attributed to inhibition of peroxidation of membrane lipid.

• 한국조경학회지
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• 제20권1호
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• pp.1-12
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• 1992

This research attempts to consider the influence of the green-contacts on the consciousness of the dwellers in the residential area of Nara. The consciousness of the dwellers is investigated by questionaire which deals with verdure, green-sufficiency and the green-contacts of dwellers. Five districts of the old residential area in Nara were selected and surveyed. The results of analysizing the investigated data summarized as follows. 1. The dwellers have a tendency to satisfy the greenery although the size of open space is small. Accordingly, the green-sufficiency is the available scale to investigate the greenery on the consciousnss of the dwellers. 2. Dwellers contact with the green space of housing as well as the surrounding failiarized-green. It was understood that the green-contacts of dwellers characterized by the kind of greenery, means and their frequency. 3. The familiarized-green contacts with the dwellers is related to the private and public uses. 4. In order to satisfy the feeling of green-sufficiency, the greenery space should be increased; it was found that green-sufficiency is satisfied by increasing the greenery space. 5. In the case of small open space, it is also possible to satisfy and attitude of green-sufficiency by introducing the familiarized-green, even if the rate of greenery space is low.

• 대한기계학회논문집A
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• 제20권2호
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• pp.594-603
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• 1996

It has been known that the life time of cold forging dies is shorten by the cracks and wear produced during the operation. Thus it is required to mak the same new one too often, At this time of making new ont the cutting work and electical discharge machining were mormally used. But the precision of product is declined in every times of making the mew dies due to the diffefence in dimensional accuracy arised from the electical discharge machining. Especially it can't meet the delivery date because the production was delayed for making another die. Furthemore it has the problem of increasing the production cost. Therfore inthis study we tried to solve these problems using the hobbing method instead of electical discharge machining.

• 한국경영과학회지
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• 제22권3호
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• pp.37-58
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• 1997

An AI approach with tabu search is designed to solve multi-level knapsack problems. The approach performs intelligent actions with memories of historic data and learning effect. These action are developed ont only by observing the attributes of the optimal solution, the solution space, and its corresponding path to the optimal, but also by applying human intelligence, experience, and intuition with respect to the search strategies. The approach intensifies, or diversifies the search process appropriately in time and space. In order to create a good neighborhood structure, this approach uses two powerful choice rules that emphasize the impact of candidate variables on the current solution with respect to their profit contribution. "Pseudo moves", similar to "aspirations", support these choice rules during the evaluation process. For the purpose of visiting as many relevant points as possible, strategic oscillation between feasible and infeasible solutions around the boundary is applied. To avoid redundant moves, short-term (tabu-lists), intemediate-term (cycle-detection), and long-term (recording frequency and significant solutions for diversfication) memories are used. Test results show that among the 45 generated problems (these problems pose significant or insurmountable challenges to exact methods) the approach produces the optimal solutions in 39 cases.lutions in 39 cases.

• 만화애니메이션 연구
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• 통권11호
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• pp.29-39
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• 2007

우리는 종종 우리가 접하고 있는 만화의 역사를 기원전까지 거슬러 올라가는 경우를 발견한다. 만화와 전혀 무관하다고 할 수는 없겠지만 이러한 입장은 동시대 만화의 특성에 대한 이해의 부족을 야기할 수 있다. 우리는 1896년, 리차드 펠튼 아웃콜트(Richard Felton Outcault)의 <옐로우 키드(Yellow Kid>)에서 오늘날까지 이어지는 만화라는 매체를, 만화의 사전(事前) 형식과는 틀린, '근대 만화(la bande dessin.e moderne)'라고 규정하고 이를 정의하려 시도했다. 이런 시도는 새롭게 등장하고 있는 '화면'이라는 지지대(support)와 기존의 만화형식과의 만남을 어떻게 이해해야 하는가에 대한 방향성을 설정하는데 도움이 될 것이라고 기대한다.

• 한국통신학회논문지
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• 제21권12호
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• pp.3215-3226
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• 1996

In this paper a K-band harmonic oscillator competitive to ordinary Push-Push type oscillators is introduced. This oscillator is composed of two-X-band dielectric resonance circuits. To favor its harmonic generation, the load effect and the bias effect are studied to allow the maximum harmonic distortion. As results, the dielectric resonated load and the class A bias are used for the 2nd harmonic generation. analytical study for modelling of voltage controlled dielectric resonator is carried out with theoretical background. The performance of the circuit is evaluated by simulation using harmonic balanced method. The novel structure has ont only a voltage tuning circuit but also an output port at fundamental frequency as the function of prescaler for phase lockede loop application on the just single oscillation structure. In experimentation, the output freqneyc of the 2nd harmonic signal is 20.5GHz and the maximum power level of output is +5.5dBm without additional post amplifiers. the harmonic oscillator exhibits -30dBc of high fundamental frequency rejection without added extra filters. The phase noise of -90dBc/Hz at 100kHz off-carrier has been achieved under free running condition, that satisfies phase noise requirement of IESS 308. The proposed oscillator may be utilized as the clean and stable fixed local oscillator in Transmit Block Upconvertor(TBU) or Low oise Block downconvertor(LNB) for K/Ka-band digital communications and satellite broadcastings.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1527-1529
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• 2001

The physicochemical properties of the LB films were by AFM. We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 2, 10, 30[mN/m]. The stable images are probably due to a s interaction between the monolayer film and substrate. We are unable to obtain molecule res in images of the films but did see a marked co between images of the bare substrate and those the network structure film deposited ont Formation that prevent when gas phase stat liquid phase state measure but Could know o matter that molecules form equal and stable when molecules were not distributed evenly, accumulated in solid state only.