• 수산해양기술연구
• /
• 제53권4호
• /
• pp.309-316
• /
• 2017

In this paper, numerical modeling is conducted to analyze the tension of an anchor line by varying the size and drag coefficient of a buoy when the trapnet is influenced by the wave and the current simultaneously. A mass-spring model was used to analyze the behavior of trapnet underwater under the influence of waves and current. In the simulation of numerical model, wave height of 3, 4, 5 and 6 m, a period of 4.4 s, and the flow speed of 0.7 m/s were used for the wave and current condition. The drag coefficients of buoy were 0.8, 0.4 and 0.2, respectively. The size of buoy was 100, 50 and 25% based on the cylindrical buoy ($0.0311m^3$) used for swimming crab trap. The drag coefficient of the trapnet, the main model for numerical analysis, was obtained by a circular water channel experiment using a 6-component load cell. As a result of the simulation, the tension of the anchor line decreased proportional to buoy's drag coefficient and size; the higher the wave height, the greater the decrease rate of the tension. When the buoy drag coefficient and size decreased to one fourth, the tension of the anchor line decreased to a half and the tension of the anchor line was lower than the holding power of the anchor even at 6 m of wave height. Therefore, reducing the buoy drag coefficient and size appropriately reduces the trapnet load from the wave, which also reduces the possibility of trapnet loss.

• 한국응용곤충학회지
• /
• 제30권2호
• /
• pp.124-129
• /
• 1991

1990년 6월부터 전남지방에서 성훼로몬을 이용한 파밤나방의 발생소장, 일일비산활동 및 기주별 가해특성을 조사한 결과 성충은 6월 중순부터 trap에 유인이 시작되어 11월 하순까지 계속되었으며 발생 peak는 비닐하우스에서 8월 중순~하순, 9월 중순~하순, 11월 상순~중순이었으며 야외포장에서도 역시 6월 중순부터 유인이 시작되어 9월 상순~하순, 10월 중순~11월 하순에 유인량이 많았으며 노지에 비해서 비닐하우스에서 peak가 20일 가량 빨랐다. 유충의 biomass에 의한 발생 가능세대수는 남부지방에서 6회로 추정되었다. 일일중 비산활동은 주로 24시 이후부터 일출전까지 활발하였으며 peak는 4시~6시 사이였다. 기주에 따른 가해특성은 외대파에 있어서는 초장 10cm이하에서 유충 밀도 및 피해주율이 가가장 높았으며, 국화는 생육에 따라 피해주율이 점차 증가하다가 생육후기에는 오히려 떨어지는 경향이었고 가해부위는 시기에 관계없이 주로 엽상이 70%이상이었고 다음은 엽하 12.3%, 정단 9.3%순이었다. 또한 안개초에 있어서 피해주는 거의 생육을 하지 못하여 개화에 이르지 못하였다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.118-118
• /
• 2011

The Nano-Floating Gate Memory(NFGM) devices with ZnO:Cu thin film embedded in Al2O3 and AlOx-SAOL were fabricated and the electrical characteristics were evaluated. To further improve the scaling and to increase the program/erase speed, the high-k dielectric with a large barrier height such as Al2O3 can also act alternatively as a blocking layer for high-speed flash memory device application. The Al2O3 layer and AlOx-SAOL were deposited by MLD system and ZnO:Cu films were deposited by ALD system. The tunneling layer which is consisted of AlOx-SAOL were sequentially deposited at $100^{\circ}C$. The floating gate is consisted of ZnO films, which are doped with copper. The floating gate of ZnO:Cu films was used for charge trap. The same as tunneling layer, floating gate were sequentially deposited at $100^{\circ}C$. By using ALD process, we could control the proportion of Cu doping in charge trap layer and observe the memory characteristic of Cu doping ratio. Also, we could control and observe the memory property which is followed by tunneling layer thickness. The thickness of ZnO:Cu films was measured by Transmission Electron Microscopy. XPS analysis was performed to determine the composition of the ZnO:Cu film deposited by ALD process. A significant threshold voltage shift of fabricated floating gate memory devices was obtained due to the charging effects of ZnO:Cu films and the memory windows was about 13V. The feasibility of ZnO:Cu films deposited between Al2O3 and AlOx-SAOL for NFGM device application was also showed. We applied our ZnO:Cu memory to thin film transistor and evaluate the electrical property. The structure of our memory thin film transistor is consisted of all organic-inorganic hybrid structure. Then, we expect that our film could be applied to high-performance flexible device.----못찾겠음......

• 한국재료학회지
• /
• 제27권1호
• /
• pp.48-52
• /
• 2017

In this study, we used I-V spectroscopy, photoconductivity (PC) yield and internal photoemission (IPE) yield using IPE spectroscopy to characterize the Schottky barrier heights (SBH) at insulator-semiconductor interfaces of Pt/$HfO_2$/p-type Si metal-insulator-semiconductor (MIS) capacitors. The leakage current characteristics of the MIS capacitor were analyzed according to the J-V and C-V curves. The leakage current behavior of the capacitors, which depends on the applied electric field, can be described using the Poole-Frenkel (P-F) emission, trap assisted tunneling (TAT), and direct tunneling (DT) models. The leakage current transport mechanism is controlled by the trap level energy depth of $HfO_2$. In order to further study the SBH and the electronic tunneling mechanism, the internal photoemission (IPE) yield was measured and analyzed. We obtained the SBH values of the Pt/$HfO_2$/p-type Si for use in Fowler plots in the square and cubic root IPE yield spectra curves. At the Pt/$HfO_2$/p-type Si interface, the SBH difference, which depends on the electrical potential, is related to (1) the work function (WF) difference and between the Pt and p-type Si and (2) the sub-gap defect state features (density and energy) in the given dielectric.

• 한국해안해양공학회지
• /
• 제15권1호
• /
• pp.33-38
• /
• 2003

가덕도 인근 연안해역에서 채취된 해저 퇴적물과 연직방향으로 배열된 표사포획장치로부터 획득된 부유물질을 이용하여 탁도계 검교정을 수행하였다. 포획된 부유물질은 모래 함량이 약 6%인 해저 퇴적물에 비하여 주로 실트 및 점토로 조성되었으며, 해저면으로부터의 놀이가 증가함에 따라 세립화하는 경향을 보였다. 해저 퇴적물에 대한 탁도계 검교정 선형 회귀식의 기울기는 최소값으로 나타났으며, 수심별로 포획된 부유물질에 의한 선형 회귀식의 기울기는 포획 고도가 증가함(즉, 입도가 감소함)에 따라서 점진적으로 증가하였다. 이러한 결과는 해저 퇴적물에 대한 탁도계 검교정 결과로부터 부유물질 농도를 환산할 경우 과대추정의 오차가 발생되며, 본 연구해역의 경우에는 그 오차가 최대 25％까지 증가할 수 있다는 것을 보여준다. 따라서 해저 퇴적물보다는 수층에서 포획된 부유물질의 입도분포를 고려하여 보정된 검교정식을 적용하는 것이 부유물질 농도의 측정오차를 최소화하는 방법으로 사료된다.

• Journal of Periodontal and Implant Science
• /
• 제36권2호
• /
• pp.345-359
• /
• 2006

Loss of maxillary molar teeth leads to rapid loss of crestal bone and inferior expansion of the maxillary sinus floor (secondary pneumatization). Rehabilitation of the site with osseointegrated dental implants often represents a clinical challenge because of the insufficient bone volume resulted from this phenomenon. Boyne & James proposed the classic procedure for maxillary sinus floor elevation entails preparation of a trap door including the Schneiderian membrane in the lateral sinus wall. Summers proposed another non-invasive method using a set of osteotome and the osteotome sinus floor elevation (OSFE) was proposed for implant sites with at least 5-6mm of bone between the alveolar crest and the maxillary sinus floor. The change of grafted material in maxillary sinus is important for implant survival and the evaluation of graft height after maxillary sinus floor elevation is composed of histologic evaluation and radiomorphometric evaluation. The aim of the present study was radiographically evaluate the graft height change after maxillary sinus floor elevation and the influence of the graft material type in height change and the bone remodeling of grafts in sinus. A total of 59 patients (28 in lateral approach and 31 in crestal approach) who underwent maxillary sinus floor elevation composed of lateral approach and crestal approach were radiographically followed for up to about 48 months. Change in sinusgraft height were calculated with respect to implant length (IL) and grafted sinus height(BL). It was evaluated the change of the graft height according to time, the influence of the approach technique (staged approach and simultaneous approach) in lateral approach to change of the graft height, and the influence of the type of graft materials to change of the graft height. Patients were divided into three class based on the height of the grafted sinus floor relative to the implant apex and evaluated the proportion change of that class (Class I, in which the grafted sinus floor was above the implant apex; Class II, in which the implant apex was level with the grafted sinus floor; and Class III, in which the grafted sinus floor was below the implant apex). And it was evaluated th bone remodeling in sinus during 12 months using SGRl(by $Br\ddot{a}gger$ et al). The result was like that; Sinus graft height decreased significantly in both lateral approach and crestal approach in first 12 months (p$MBCP^{TM}$ had minimum height loss. Class III and Class II was increased by time in both lateral and crestal approach and Class I was decreased by time. SGRI was increased statistically significantly from baseline to 3 months and 3 months(p<0.05) to 12 months(p$ICB^{(R)}$ single use, more reduction of sinusgraft height was appeared. Therefore we speculated that the mixture of graft materials is preferable as a reduction of graft materials. Increasing of the SGRI as time goes by explains the stability of implant, but additional histologic or computed tomographic study will be needed for accurate conclusion. From the radiographic evaluation, we come to know that placement of dental implant with sinus floor elevation is an effective procedure in atrophic maxillary reconstruction.

• 한국진공학회지
• /
• 제16권3호
• /
• pp.197-204
• /
• 2007

p-형 실리콘 기판 위에 수 ${\AA}$ 두께의 어븀 금속을 증착하고, 후열처리 과정을 통하여 어븀-실리사이드/p-형 실리콘 접합을 형성하였다. 초고진공 자외선 광전자 분광 실험을 통하여 증착한 어븀의 두께에 따라 어븀-실리사이드의 일함수가 4.1 eV까지 급하게 감소하는 것을 관찰하였으며, X-ray 회절 실험에 의하여 형성된 어븀 실리사이드가 주로 $Er_5Si_3$상으로 구성되어 있음을 밝혔다. 또한, 어븀-실리사이드/p-형 실리콘 접합에 알루미늄 전극을 부착하여 쇼트키 다이오드를 제작하고, 전류전압 곡선을 측정하여 쇼트키 장벽의 높이를 산출하였다. 산출된 쇼트키 장벽의 높이는 $0.44{\sim}0.78eV$이었으며 어븀 두께 변화에 따른 상관 관계를 찾기 어려웠다. 그리고 이상적인 쇼트키 접합을 가정하고 이미 측정한 일함수로부터 산출한 쇼트키 장벽의 높이는 전류-전압 곡선으로부터 산출한 값에 크게 벗어났으며, 이는 어븀-실리사이드가 주로 $Er_5Si_3$ 상으로 구성되어 있고, $Er_5Si_3/p-$형 실리콘 계면에 존재하는 고밀도의 계면 상태에 기인한 것으로 사료된다.

• 한국응용곤충학회지
• /
• 제45권1호
• /
• pp.37-43
• /
• 2006

끈끈이 트랩을 이용하여 대만총채벌레를 효과적으로 예찰하고 유인 포획할 수 있는 방법을 찾고자 논산의 수확 중인 딸기재배 비닐하우스에서 수행하였다. 끈끈이 트랩의 색상으로는 노란색, 파란색, 흰색을 이용하였으며, 끈끈이 트랩의 설치 높이는 딸기의 캐노피 수준에 맞추어 지상에서 50cm(Upper)와 10 cm(Lower)인 곳에 수직으로 설치를 하고 지면(Ground)에 뉘어 놓았다. 각각의 높이에서 각 색상별 끈끈이 트랩에 유인 포획되는 대만총채벌레는 매우 많은 차이를 나타냈으며, 파란색의 끈끈이 트랩에 가장 많이 유인 포획되었다. 또한 설치 높이를 달리한 경우에는 지상 50 cm높이에 설치한 끈끈이 트랩에서 가장 많이 유인 포획되었다. 그렇지만, 각 시험 구획별로 딸기 꽃에 서식하고 있는 대만총채벌레의 개체군은 차이를 보이지 않았다.

• 한국전기전자재료학회논문지
• /
• 제25권2호
• /
• pp.85-90
• /
• 2012

In this paper, we compared and analyzed 3D silicon-oxide-nitride-oxide-silicon (SONOS) multi layer flash memory devices fabricated on nitride or oxide layer, respectively. The device fabricated on nitride layer has inferior electrical properties than that fabricated on oxide layer. However, the device on nitride layer has faster program / erase speed (P/E speed) than that on the oxide layer, although having inferior electrical performance. Afterwards, to find out the reason why the device on nitride has faster P/E speed, 1/f noise analysis of both devices is investigated. From gate bias dependance, both devices follow the mobility fluctuation model which results from the lattice scattering and defects in the channel layer. In addition, the device on nitride with better memory characteristics has higher normalized drain current noise power spectral density ($S_{ID}/I^2_D$>), which means that it has more traps and defects in the channel layer. The apparent hooge's noise parameter (${\alpha}_{app}$) to represent the grain boundary trap density and the height of grain boundary potential barrier is considered. The device on nitride has higher ${\alpha}_{app}$ values, which can be explained due to more grain boundary traps. Therefore, the reason why the devices on nitride and oxide have a different P/E speed can be explained due to the trapping/de-trapping of free carriers into more grain boundary trap sites in channel layer.

• 한국응용곤충학회지
• /
• 제61권1호
• /
• pp.77-83
• /
• 2022

본 연구는 담배거세미나방 국내 개체군의 예찰에 필요한 성유인제의 최적 조성을 찾기 위해 수행하였다. 담배거세미나방 암컷 성충에서 알려진 두 성페로몬 성분인 (Z,E)-9,11-tetradecadienyl acetate, (Z,E)-9,12-tetradecadienyl acetate를 5.5 ~ 10.0 및 9:1 ~ 99.1, 9:1 ~ 39:1 비율 사이에 여러 조성으로 만들어 고무격막 방출제에 담아 펀넬트랩을 이용하여 콩과 땅콩포장에서 수컷 성충에 대한 유인력을 비교한 결과, 두 성분의 19:1 비율이 가장 적절한 유인 조성으로 결정하였다. 그러나 Z9E11-14:Ac 단독 성분 미끼에는 수컷 성충이 거의 유인되지 않았다. 이 결과는 담배거세미나방 성충 예찰용의 성유인제 구성에는 두 성페로몬 화합물이 반드시 필요한 성분임을 나타낸다. 미끼에 담긴 성페로몬은 0.1 ~10 mg 사이에서 함량이 증가할수록 유인된 수가 많았다. 적절한 트랩 설치 높이는 1.5 m로 결정하였다.