• 한국결정학회지
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• 제12권4호
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• pp.233-238
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• 2001

1㎛ 이하로 집속된 방사광원으로부터의 x-선을 이용하여 새로운 분석법인 x-선 미세회절(x-ray microdiffraction)을 사용하면 다결정시료 내 grain들의 방위나 strain의 국지적 분포를 정밀하게 측정할 수 있다. 포항가속기연구소 방사광원의 x-ray microbeam 실험 장치를 사용하여 찍은 Laue 사진을 측별히 쓰여진 분석 software를 이용하여 분석함으로써 고집적회로에 쓰이는것과 같은 방법으로 제작된 Si wafer 상의 다른 선폭의 구리 도선들이 가지는 texture 를 밝혀내었다. 실험시 x-ray빔의 크기는 2×3㎛²정도이었으며, 분석 결과에의하면 선폭 1㎛도선에서는 grain들이 방위가 특정한 방향성이 없는 반면, 선폭 20㎛도선의 중앙부분에서는 〈111〉fiber texture 가 관측되었다. Grain들의 크기는 선폭 1㎛의도선에서 2∼5㎛, 선폭 20㎛의도선에서는 6∼8㎛로 측정되었다.

• 농촌계획
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• 제25권2호
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• pp.63-74
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• 2019

As the awareness of food security has increased, the Korean government has established national projects, such as Saemangeum proclaimed land, to secure sources of grain. Saemangeum is a large-scale agricultural area that was constructed to maintain preparedness for unstable food markets. This study aims to develop a $6^{th}$ Industrialization Model (SIM) for Saemangeum Grain Complex by applying feasible strategies to wheat and two-rowed barley which have low self-sufficiency rates. In addition, this study estimates the potential economic value of each development strategy associated with a sixth industrialization model to create higher added values from production, processing and tourism experiences. The strategic plan for primary, secondary, and tertiary industries is to combine cultivating and processing wheat and two-rowed barley for sales and linking them to tourism experience. This study shows value added from the combination of the primary, secondary and tertiary industry of wheat and two-rowed barley are 7.5 and 23.0 times more than those of the primary and tertiary industry combination, respectively. Through branding Saemangeum Grain Complex's products, such as Saemanguem bread and craft beer, would further enhance the economic benefits derived from the complex.

• 대한전자공학회논문지SD
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• 제43권10호
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• pp.61-67
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• 2006

본 논문에서는 Poly-Si의 불규칙한 Grain boundary 분포로 인해 발생하는 문턱전압의 변화에 대해서도 일정한 전류를 흘려줄 수 있는 전류원을 제안하였다. 기존의 문턱전압 보상 전류원에 비해 넓은 입력전압 범위에서도 포화영역의 특성이 매우 향상되었으며 문턱전압의 변화에 따른 전류의 오차를 감소시킬 수 있었다. 마지막으로 HSPICE 시뮬레이션 과정을 통해 Poly-Si TFT의 특성곡선과 제안된 전류원의 특성곡선을 비교하였으며 각각의 입력전압에 대한 문턱전압의 변화에 따른 출력전류의 상대오차를 측정하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권12호
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• pp.3200-3219
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• 2013

This paper proposes an adaptive combined scalable video coding (CSVC) system for video transmission over MIMO-OFDM (Multiple-Input Multiple-Output-Orthogonal Frequency Division Multiplexing) broadband wireless communication systems. The scalable combination method of CSVC adaptively combines the medium grain scalable (MGS), the coarse grain scalable (CGS) and the scalable spatial modes with the limited feedback partially from channel state information (CSI) of MIMO-OFDM systems. The objective is to improve the average of peak signal-to-noise ratio (PSNR) and bit error rate (BER) of the received video stream by exploiting partial CSI of video sources and channel condition. Experimental results show that the delivered quality using the proposed adaptive CSVC over MIMO-OFDM system performs better than those proposed previously in the literature.

• Journal of Welding and Joining
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• 제31권3호
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• pp.17-21
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• 2013

Sn whiskers are one of the serious causes of the failure of electronics. Sn whiskers grow spontaneously from Sn-based, lead-free finished surfaces, even at room temperature. A primary factor of these Sn whiskers growth is compressive stress, which enhances the diffusion of Sn or other elements. The sources of compressive stress are the growth of non-uniform large intermetallic compounds along the interface between the Sn grain boundary and Cu substrate. Recent studies revealed the methods for reducing Sn whisker growth. This paper gives an overview about recent researches for mitigation methods of Sn whisker growth during nearly room temperature storage.

• 천문학회보
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• 제46권1호
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• pp.57.1-57.1
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• 2021

The icy mantles of interstellar grains are developed by the freeze-out of interstellar molecules and atoms onto grain surfaces. The ice molecules become more complex by surface chemistry induced directly by high energy photons or by the thermal energy diffused over heated grain surface. Therefore, the ice composition is an important tracer of physical conditions where the ices form. Ices have been studied via their absorption features against continuum sources, such as young stellar objects or evolved background stars, in infrared wavelengths. The Spitzer IRS was the most sensitive spectrometer for the observations of infrared ice absorption features. We has been developing an automated analysis tool for the Spitzer IRS spectra, especially for the 15 ㎛ CO₂ bending mode. The 15 ㎛ CO₂ absorption feature is very useful for the study of accretion process in star formation since its spectral shape varies with thermal condition of the dust grains. Eventually, this tool will cover the whole range of the Spitzer IRS spectrum (5~20 ㎛).

• 한국식품영양과학회지
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• 제23권5호
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• pp.767-773
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• 1994

1989년도 국민영양조사의 식품섭취조사에서 조사된 전국규모의 자료를 중심으로총 566종의 식품에 대해 식이성섬유소 분석치를 적용하여 그 섭취량을 분석한결과는 다음과 같다. 식이성섬유소의 섭취량은 전국이 17.53g, 도시평균이 17.91g, 대도시가 18.07g, 중소도시가 17.56g, 농촌이 16.61g으로 나타났으며, 이중 95% 정도를 식물성 식품으로 부터 섭취하고 있었다. 식품군별 식이성섬유소 섭취의 기여도는 채소류>곡류 및 그 제품>해조류>과실류>버섯류>두류 및 그 제품의 순이었다. 곡류 및 그 제품에서 가장 중요한 급원은 쌀로 전국평균이 12.2%였으며, 그 다음이 라면, 식빵, 보리쌀의 순이었으며, 해조류에서 가장 중요한 급원은 미역이었고, 그 다음이 김과 파래였다. 과실류에서는 사과와 감이 버섯류에서는 느타리버섯과 표고버섯이, 두류에서는 콩나물이 식이성섬유소의 중요한 급원이었다. 채소류는 식이성섬유소의 가장 중요한 급원으로, 전국의 경우 32.4%, 도시평균은 31.4%, 대소시에서는 30.8%, 중소도시에서는 33.0%, 농촌에서는 34.8%를 차지하였다. 그 중 가장 중요한 급원은 배추김치와 붉은 고추가 1, 2위를 차지하였다. 전국적으로 식이성섬유소 섭취량 분포를 보면 도수분포(Frequency distribution)의 계급구간을 5g으로 섭취하는 가구로 33.9%를 차지하엿고, 5g 이하나 35g 이상 섭취하는 가구도 0.8%와 5.2%를 나타내었다.

• 한국세라믹학회지
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• 제27권8호
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• pp.1011-1019
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• 1990

Pyrophyllite, which has low impurities, was used in the synthesis of mullite to decrease the glass phase, which can be formed from impurities such as alkali and alkali earth elemetns present in raw materials. But, as pyrophyllite has less alumina content than other aluminosilicate materials such as kaolin, more alumina sources were needed in the synthesis of mullite. In other to investigate the effect of particle size of alumina sources on the mullitization of pyrophyllite, aluminum hydrate gel and activated alumina were used. When activated alumina, which has large particle size, was added to pyrophyllite, mullitization was not fully accomplished regardless of temprature. In the case of aluminum hydrate gel, which has small particle size, the maximum yield of mullite was about 90.3% at 1700$^{\circ}C$, and grain size of mullite was larter than the case of activated alumina was added.

• Journal of Biosystems Engineering
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• 제7권1호
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• pp.17-32
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• 1982

The binders introduced in Korea were originally designed to be used for Japonica-type varieties which have relatively long stem and are highly resistant to shattering. In order to use it for Tongil varieties which are short and easy to be shattered, mechanical modifications are necessary to reduce a grain loss incurred during binder operation. This study was intended to investigate analytically and experimentally the major sources of grain losses caused by three kinds of binders now introduced in Korea. Actual modification for each of three binders was done and experimentally compared to see if any improvement on grain loss was achieved. The results obtained in this study are summarized as follows; 1. It was required that the power transmission of binder should have a shifting mechanism so that velocities of pick-up and traveling units could be changed independently as desired according to the Japonica-type and Tongil varieties. In other words, the desired velocity of traveling unit should be obtained by shifting the transmission and the velocity of pick-up unit should be selected by reaping clutch according to the variety independent of the velocity of traveling unit as shown in Fig. 6. 2. To reduce grain loss it was desired that the moving parts of the pick-up unit should have the lowest possible velocities in harvesting Tongil varieties, unless the reduction of the speed be hindered the conveyance of the material. Based on the study, it was concluded that the velocities of pick-up unit be reduced by about 35% of those of the existing units. 3. It was found that the lug at the upper rotating section of pick-up case gave a severe impact on the ears of rice to increase grain loss. The optimum design of pick-up case to protect the ears from the protruding part of the lug was recommended by the result of analysis of the trajectory of the end-point of lug at the position. 4. It was proved analytically and experimentally that pick-up unit at the lower-rotating part was the other important source of grain loss in pick-up and divider assembly. In order to reduce a grain loss incurred by lugs at their lower-rotating section, it was suggested to improve it by (1) widening the space between right and left lower-rotating section, (2) shortening the length of lugs, (3) enlargement of the angle between the pick-up case and ground-level, and (4) attaching guard to right and left dividers so that the rotating lug could not give a high impact to the paddy hill. 5. Pick-up and divider assembly of the original binder of three models studied was modified according to the suggestions that were given by the preliminary study. Field test showed that the modified binders were able to reduce grain losses by about 0.4-0.7 percentage points compared to those without modification.

• 열처리공학회지
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• 제9권1호
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• pp.12-18
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• 1996

Austenite(${\gamma}$) grain size, ${\varepsilon}$ martensite volume fraction and damping capacity of Fe-17%Mn alloy have been investigated as a function of solution treatment temperature of $600^{\circ}C$ to $1100^{\circ}C$. With increasing the solution temperature, ${\gamma}$ grain size, ${\varepsilon}$ martensite content and damping capacity are increased, while the hardness is decreased. When ${\gamma}$ grains are small, ${\varepsilon}$ plates grow in only one direction in each ${\gamma}$ grain. However, if the ${\gamma}$ grains are large in accordance with high solution treating temperature, several ${\varepsilon}$ variants with different orientations are formed and intersected each other in each ${\gamma}$ grain. In spite of small ${\varepsilon}$ martensite content, the damping capacity of the specimen which was annealed at $700^{\circ}C$, followed by subzero treatment at $-196^{\circ}C$, is almost equal to that of the specimen annealed at $1000^{\circ}C$ and subsequently quenched to room temperature. From this result it is suggested that the damping capacity of Fe-17%Mn alloy having fine ${\gamma}$ grains is mainly attributed to the movement of ${\gamma}/{\varepsilon}$ interface without the operation of other damping sources such as ${\varepsilon}/{\varepsilon}$ boundaries and stacking faults in ${\varepsilon}$ reported previously.