• 한국경제지리학회지
• /
• 제11권1호
• /
• pp.111-129
• /
• 2008

본 연구는 1990년대 이후에 나타난 중앙정부 지역정책의 패러다임 변화를 논의하였다. 특히, 지역정책의 발상지인 영국에서 1928년부터 2000년대까지 전개되어온 중앙정부의 지역정책 변화를 살펴보되 최근 10년간의 동향에 초점을 맞추었다. 최근 10년간의 주요 변화는 지역격차 완화를 위해 규제와 지원을 통해 산업과 인구의 공간분포를 변형시키고자 하는 중앙정부의 개입주의적인 하향식 지역정책이 지역경쟁력 강화와 그것을 위한 지역발전의 분권화를 추진하는 지역정책으로 전환하고 있다는 것이다. 그리고 그러한 전환 속에서도 영국 중앙정부는 지역격차 완화를 계속 추구해오고 있다. 또한 본고는 영국 중앙정부의 지역정책 변화가 대내외 환경 변화 속에서 우리나라 중앙정부의 향후 지역정책 방향 설정에 던져주는 시사점을 제시하였다.

• Wind and Structures
• /
• 제23권2호
• /
• pp.127-142
• /
• 2016

Aerodynamic effects, such as drag force and flow-induced vibration (FIV), on civil engineering structures can be minimized by optimally modifying the structure shape. This work investigates the turbulent wake of a square prism with its faces modified into a sinusoidal wave along the spanwise direction using three-dimensional large eddy simulation (LES) and particle image velocimetry (PIV) techniques at Reynolds number $Re_{Dm}$ = 16,500-22,000, based on the nominal width ($D_m$) of the prism and free-stream velocity ($U_{\infty}$). Two arrangements are considered: (i) the top and bottom faces of the prism are shaped into the sinusoidal waves (termed as WSP-A), and (ii) the front and rear faces are modified into the sinusoidal waves (WSP-B). The sinusoidal waves have a wavelength of $6D_m$ and an amplitude of $0.15D_m$. It has been found that the wavy faces lead to more three-dimensional free shear layers in the near wake than the flat faces (smooth square prism). As a result, the roll-up of shear layers is postponed. Furthermore, the near-wake vortical structures exhibit dominant periodic variations along the spanwise direction; the minimum (i.e., saddle) and maximum (i.e., node) cross-sections of the modified prisms have narrow and wide wakes, respectively. The wake recirculation bubble of the modified prism is wider and longer, compared with its smooth counterpart, thus resulting in a significant drag reduction and fluctuating lift suppression (up to 8.7% and 78.2%, respectively, for the case of WSP-A). Multiple dominant frequencies of vortex shedding, which are distinct from that of the smooth prism, are detected in the near wake of the wavy prisms. The present study may shed light on the understanding of the underlying physical mechanisms of FIV control, in terms of passive modification of the bluff-body shape.

• Tribology and Lubricants
• /
• 제26권2호
• /
• pp.136-141
• /
• 2010

In an oil hydraulic vane pump for an automobile, it is very important that the vane doesn't separate from the camring inner race during the operation of the vane pump. The vane generally has not only the oil hydraulic force acting on the bottom face to contact to camring inner race but there is also an inertial force and viscous force. Because the oil hydraulic force is much larger than the other forces, the contact state between the vane tip and the camring inner race is sufficient. However, the contact state between the vane tip and the camring inner race is only affected by the inertial and viscous forces during the delivery of the vane pump, because the oil hydraulic force acting on the vane is in equilibrium. If the inertial force is larger than the viscous force, which happens when the vane is separated from the camring inner race, the delivery of the vane pump can become unstable or the volume efficiency can become decrease rapidly. Therefore, in this paper, the state of the contact between the vane and the camring is considered. The results show that the rotating speed of the shaft, the operating temperature of the oil, the clearance between the vane and the rotor, and the mass of the vane exert a great influence on the state of the contact between the vane and the camring.

• 한국전자파학회논문지
• /
• 제24권10호
• /
• pp.964-970
• /
• 2013

본 논문은 적층된 칩 사이의 3차원 대역 통과 무선 통신 인터페이스를 제안한다. 제안 방법은 적층된 칩 사이의 작은 커패시턴스를 포함한 3차원 공진기를 이용하여 자주 주파수 발진기(free running oscillator)를 구성하고, 이 발진기를 진폭 변조하여 추가적인 정합회로 없이 수신단에서 포락선 검파를 통해 신호를 검출한다. 제안 방법을 검증하기 위해 110 nm CMOS 공정을 사용하여 송수신 칩을 설계하고, 제작하여 50 ${\mu}m$ 두께의 칩 사이에 2 Gb/s의 데이터 전송 속도를 확인하였다. 제작한 칩은 동작전압 1.2 V를 사용하며, 송수신 칩을 합하여 4.32 mW의 전력을 소모한다. 칩의 크기는 송신단은 0.045 $mm^2$이고, 수신단은 0.029 $mm^2$이다.

• 한국토양환경학회지
• /
• 제1권1호
• /
• pp.19-27
• /
• 1996

물에 쉽게 용해되지 않고 분리된 유체면을 갖는 액체를 NAPO(nonaqueous phase liquids)이라 한다. 유기용제와 석유탄화수소와 같은 NAPL에 의한 지하수 오염은 지하에서의 장기간의 지속성 및 다량의 지하수를 오염시키는 능력 때문에 주요 관심 대상물질이다 누출된 DNAPU(denser- than-water NAPL)은 궁극적으로 포화 대수층을 통과하여 바닥에 DNAPL pool을 이루게 된다. 이러한 pool로부터의 용해는 분자확산계수, 연직분산도, 지하수유속, 용해도 및 pool의 길이에 지배된다. 본 연구에서는 이러한 DNAPL pool의 용해를 모사하기 위해 DNAPL용해실험을 하여 연직 횡분산계수를 산정하였다. 본 연구에서 사용된 실험조건하에서 수행한 실험결과 산정된 연직 횡분산계수는 침투유속이 59.2cm/day, 94.3cm/day 및 158.0cm/day인 경우 각각 1.86$cm^2$/day, 2.90$cm^2$/day 및 4.51$cm^2$/day 이었고, 연직 횡분산도는 0.03024cm 이었다.

• 한국결정성장학회지
• /
• 제25권1호
• /
• pp.32-34
• /
• 2015

PVT(Physical vapor transport)법으로 벌크형 종자 결정을 이용하여 AlN 단결정을 성장 시켰다. 성장과정은 고주파 유도 가열 코일을 이용한 방법으로 진행되었다. 카본 도가니의 하단에 원료 분말을 장입하고 종자 결정은 도가니의 상부에 부착하였다. 성장 조건으로 온도는 $2000{\sim}2100^{\circ}C$ 사이에서 이루어 졌으며 챔버내 압은 $1{\times}10^{-1}{\sim}200$ Torr로 유지하였다. 또한 가열 위치를 결정짓는 hot-zone 조절이 성장의 시간이 진행됨에 따라 수정되었다. 이러한 조건하에 약 600시간 성장시킨 결과로 장축 직경 17 mm 두께 7 mm의 AlN 단결정이 얻어졌으며, Laue X-Ray 장치을 이용하여 성장된 결정의 방향을 조사한 결과 R방향[011]으로 성장 되었음을 알 수 있었다.

• 비교문화연구
• /
• 제39권
• /
• pp.241-286
• /
• 2015

This study explores how folktales' motifs are used in diverse cultural contents such as literature, movies, or comics. More precisely, it is concerned with mysterious characters like Babayaga and Koshchei who appear in Russian fairytales. When the motifs of the reviewed literature are analyzed, the following three criteria are used for classification: New Writing, Rewriting, and New Version. Or course, it is New Writing that is far from the original work. Most of the collected works, including Joan Aiken's The Kingdom Under the Sea, Patricia Polacco's Babushka's Doll, Babushka Baba Yaga, and Tai?-Marc Le Thanh's BABAYAGA, belong to New Writing. The New Writing type mainly focuses on Babayaga's secluded life. In fairytales, Babayaga is depicted as the goddess of Mother Earth, the heroine of the Nature, or the ruler of the Animal Kingdom. That is why she lives in the deep and uninhabited wood. She is related to the Coming of Age ceremony. Her 'Hut on hen's legs' is an obstacle for immature protagonists to face before they come of age. Protagonists are supposed to solve the problems posed by Babayaga. If they succeed, they can get her magical help so as to complete their final mission. Babayaga is likely to appear as their antagonist. Protagonist may be subjected to a terrible ordeal created by Babayaga, and then come of age by recovering from that ordeal. Sometimes, Babayaga helps protagonists to get a grip on reality. That is why she lives in a hut in the deep and dark forest which is on the borderline between life and death. On the other hand, Marianna Mayer's Baba Yaga and Vasilisa the Brave has been classified as a controversial work between New Writing and Rewriting. It is apparently closer to New Version. However, it cannot be classified as a work of New Version because the author incorporates 'probability' into her work. Among the reviewed works, it is Korean Writer Rye, Kami's The Spider Woman's House that best reflects the essence of Babayaga. Babayaga and other characters are amusing in movies because most of the movies are animations for children. In one sense, it is positive that the scary characters in folktales are approachable to children. In other sense, however, it is regrettable that symbolic motifs are completely eliminated. In Mike Mignola's Hellboy, Japanese animations such as Index or Narutaru, on-line games such as Cabal or Vampire: The masquerade, the essence of the supernatural characters in folktales is completely eliminated, and only their 'belligerent power' stands out. It is desirable to put stories into perspective whether they are written or told. The literature property of folktales provides a special opportunity to readers. In this light, a variety of motifs have a good reason to be reborn as modern cultural contents. The bottom line is to maintain its true nature.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 하계학술대회 논문집
• /
• pp.311-311
• /
• 2009

Carbon nanotubes (CNTs) belong to an ideal material for field emitters because of their superior electrical, mechanical, and chemical properties together with unique geometric features. Several applications of CNTs to field emitters have been demonstrated in electron emission devices such as field emission display (FED), backlight unit (BLU), X-ray source, etc. In this study, we fabricated a CNT cathode by using filtration processes. First, an aqueous CNT solution was prepared by ultrasonically dispersing purified single-walled CNTs (SWCNTs) in deionized water with sodium dodecyl sulfate (SDS). The aqueous CNT solution in a milliliter or even several tens of micro-litters was filtered by an alumina membrane through the vacuum filtration, and an ultra-thin CNT film was formed onto the alumina membrane. Thereafter, the alumina membrane was solvated by acetone, and the floating CNT film was easily transferred to indium-tin-oxide (ITO) glass substrate in an area defined as 1 cm with a film mask. The CNT film was subjected to an activation process with an adhesive roller, erecting the CNTs up to serve as electron emitters. In order to measure their luminance characteristics, an ITO-coated glass substrate having phosphor was employed as an anode plate. Our field emitter array (FEA) was fairly transparent unlike conventional FEAs, which enabled light to emit not only through the anode frontside but also through the cathode backside, where luminace on the cathode backside was higher than that on the anode frontside. Futhermore, we added a reflecting metal layer to cathode or anode side to enhance the luminance of light passing through the other side. In one case, the metal layer was formed onto the bottom face of the cathode substrate and reflected the light back so that light passed only through the anode substrate. In the other case, the reflecting layer coated on the anode substrate made all light go only through the cathode substrate. Among the two cases, the latter showed higher luminance than the former. This study will discuss the morphologies and field emission characteristics of CNT emitters according to the experimental parameters in fabricating the lamps emitting light on the both sides or only on the either side.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.315-315
• /
• 2017

In Japan, more than 80 % of soybean growing area is converted fields and excess water is one of the major problems in soybean production. For example, recent study (Yoshifuji et al., 2016) suggested that in the fields of shallow groundwater level (GWL) (< 1m depth), rising GWL even in a short period (e.g. 1 day) causes inhibition of soybean growth. Thus it becomes more and more important to predict GWL and soil moisture in detail. In addition to conventional surface drainage and underdrain, FOEAS (Farm Oriented Enhancing Aquatic System), which is expected to control GWL in fields adequately, has been developed recently. In this study we attempted to predict GWL and soil moisture condition at the converted field with FOEAS in Biwa lake reclamation area, Shiga prefecture, near the center of the main island of Japan. Two dimensional HYDRUS model (Simuinek et al., 1999) based on common Richards' equation, was used for the calculation of soil water movement. The calculation domain was considered to be 10 and 5 meter in horizontal and vertical direction, respectively, with two layers, i.e. 20cm-thick of plowed layer and underlying subsoil layer. The center of main underdrain (10 cm in diameter) was assumed to be 5 meter from the both ends of the domain and 10-60cm depth from the surface in accordance with the field experiment. The hydraulic parameters of the soil was estimated with the digital soil map in "Soil information web viewer" and Agricultural soil-profile physical properties database, Japan (SolphyJ) (Kato and Nishimura, 2016). Hourly rainfall depth and daily potential evapo-transpiration rate data were given as the upper boundary condition (B.C.). For the bottom B.C., constant upward flux, which meant the inflow flux to the field from outside, was given. Seepage face condition was employed for the surrounding of the underdrain. Initial condition was employed as GWL=60cm. Then we compared the simulated and observed results of volumetric water content at depth of 15cm and GWL. While the model described the variation of GWL well, it tended to overestimate the soil moisture through the growing period. Judging from the field condition, and observed data of soil moisture and GWL, consideration of soil structure (e.g. cracks and clods) in determination of soil hydraulic parameters at the plowed layer may improve the simulation results of soil moisture.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2019년도 학술발표회
• /
• pp.232-232
• /
• 2019

The persistence of drought periods and water scarcity is a growing public concern, as climate change projections indicate a more critical scenario in the future. The sustainability of water resources for the increasing population, and to ensuring crop production will unarguably be a daunting task for the water resources managers, with a projected 9.8 billion people by 2050 as well as the need to increase food production by 70 to 100%. Consequently, there is a need for significant irrigation water use for more crop production in the face of stiff competition among water users. However, the available natural resources are already over-constrained, and the allocation of more resources for food production is not feasible. Currently, about two-thirds of global water withdrawer is used by the agricultural sector while 48% of water resources in Korea is used for agricultural production. Despite the apparent ecological deficit and unfavorable conditions of resources utilization, a staggering amount of food waste occurs in the country. Moreover, wastage of food translates to waste of all the resources involved in the food production including water resources. Food waste can also be considered a serious potential for economic and environmental problems. Hence, exploring an alternative approach to efficient resources utilization in a more sustainable way can ensure considerable resources conservation. We hypothesized that reducing food waste will decline the demand for food production and consequently reduce the pressure on water resources. We investigated the food wastage across the food supply chain using the top-down datasets based on the FAO mass balance model. Furthermore, the water footprint of the estimated food wastage was assessed using the representative of selected food crops. The study revealed that the average annual food wastage across the food supply chain is 9.05 million tonnes, signifying 0.51 kg/capita/day and 48% of domestic food production. Similarly, an average of 6.29 Gm3 per annum of water resources was lost to food wastage, which translates to 40% of the total allotted water resources for agriculture in the country. These considerable resources could have been conserved or efficiently used for other purposes. This study demonstrated that zero food waste generation would significantly reduce the impact on freshwater resources and ensure its conservation. There is a need for further investigation on the food waste study using the bottom-up approach, specifically at the consumer food waste, since the top-down approach is based on estimations and many assumptions were made.