• 대한기계학회논문집
• /
• 제16권11호
• /
• pp.2196-2202
• /
• 1992

본 연구에서는 초전도 양자 간섭장치(SQUID, superconductiong quantum inte- rference device)를 냉각시킬 수 있는 정도의 소용량(3.995K에서 0.1W)의 GM/J-T 냉동 기에 대하여 요구되는 냉각용량을 만족시키면서 최대의 성능을 나타낼 수 있는 열교환 기의 면적배분 조건을 구하였다. 즉 냉동 성능을 알고 있는 상용 2단 GM 냉동기와 소형 극저온 냉동기에 널리 사용되는 열교환기로 이루어진 복합적인 GM/J-T 냉동기에 대하여 열교환기 총면적이 주어졌을 때, J-T 회로내의 냉매(헬륨)의 유량과 각 열교환 기 전열 면적의 비를 변수로 최적설계를 행하였다.

• 한국양식학회지
• /
• 제11권4호
• /
• pp.449-455
• /
• 1998

능성어와 같은 고급해산어의 양식에 대한 연구가 활발히 진행되고 있지만, 부화후 섭이 개시 직후의 자어의 구경이 작은 이유 때문에 현재 배양하고 있는 로티퍼 보다 소형의 먹이 생물이 요구되고 있다. 이 실험에서는 이와 같은 현실적인 요구사항에 부응하여 다양한 사이즈의 먹이 생물을 이용 가능하도록 하는 것을 목적으로 S형 로티퍼B. rotundiformis와 자유 유영형의 사이 크로포이다의 코페포다 Apocyclops sp.에게 T. suecica를 먹이로 급이하면서 두종을 혼합 배양하였다. 실험조건은 수온 25${\circ}C$, 염분 22ppt, 배양수량은 50ml의 비이커에 사육수 40ml, 실험기간 16일간, 2일마다 전 개체수를 계수하면서 암흑조건하에서 배양했다. 단독 배양구의 코페포다 Apocyclops는 실험기간 동안에 계속 대수증식을 하여 평균 최고 밀도는 12개체/ml에 달하였다. 더욱이 코페포다 Apocyclops의 증식은 코페포다 Apocyclops 단독 배양의 경우보다도 로티퍼 b. rotundiformis 와 혼합 배양했을때가 탁월한 증식을 보였다(최고 밀도는 20.15${\pm}$4.45개체/ml). 특히 로티퍼와 Apocyclops의 혼합 배양구에서 노플리우스의 개체수는 9.88${\pm}$1.38개체/ml로서 코페포다 Apocyclops 단독배양의 경우와 비교하면 약 2배 이상의 증식을 보였다. 그러나, 로티퍼 B. rotundiformis의 증식은 단독 배양에 비하여 코페포다 Apocyclops와 혼합 배양함으로서 그 증식이 크게 억제되었다. 먹이로서 급이한 T. suecica는 로티퍼 B. rotundiformis 단독 배양구와 코페포다 Apocyclops와의 혼합 배양구에서는 실험 개시 후 10일째부터 잔존량을 거의 관찰할 수 없었다. 그러나, 코페포다 Apocyclops는 적극적으로 T. suecica을 섭이하지는 않았다. 즉, 로티퍼와 코페포다간의 먹이 경쟁관계는 관찰할 수 없었다. 이 연구에서는 소구경 어종의 종묘 생산 초기과정에서 자어의 기아현상으로 인한 초기 대량 폐사와 같은 문제점을 해결하기 위하여 일반적으로 배양중인 로티퍼(사이즈180${\mu}$m 전후) 보다 더 적은 사이즈의 먹이 생물을 검색하기 위한 한 방법으로서 소구경 어종들이 요구하고 있는 먹이생물의 사이즈, 즉 150${\mu}$m 전후의 노플리우스가 생산 가능한 코페포다 Apocyclops를 로티퍼와 혼합 배양하였다. 이와 같이 다양한 사이즈의 먹이생물을 혼합배양하여 사육 대상 자치어에게 먹이로서 급이 가능하다면, 소구경 어종이 요구하는 사이즈의 문제는 극복 가능할 것이다. 뿐만 아니라, 사이즈 280${\mu}$m 전후의 대형 로티퍼(B. plicatilis)와 부화직후의 알테미아 유생(사이즈 950${\mu}$m)을 사용하고 있는 현재의 먹이 생물 급이 계열에서 요구되는 중간 사이즈 (사이즈300-500${\mu}$m 전후) 먹이생물의 공급도 해결 가능할 것으로 생각된다.

• The Journal of Advanced Prosthodontics
• /
• 제2권3호
• /
• pp.65-70
• /
• 2010

Large oro-facial defects result from cancer treatment consequences in serious functional as well as cosmetic deformities. Acceptable cosmetic results usually can be obtained with a facial prosthesis. However, retention of a large facial prosthesis can be challenging because of its size and weight. This article describes prosthetic rehabilitation of a 57-year-old man having a right lateral mid-facial defect with intraoral-extraoral combination prosthesis. A modified technique to fabricate a hollow substructure in heat-polymerizing polymethyl-methacrylate to support silicone facial prosthesis was illustrated. The resultant facial prosthesis was structurally durable and light in weight facilitating the retention with magnets satisfactorily. This technique is advantageous as there is no need to fabricate the whole prosthesis again in case of damage of the silicone layer because the outer silicone layer can be removed and re-packed on the substructure if the gypsum-mold is preserved.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2011년도 전력전자학술대회
• /
• pp.296-297
• /
• 2011

Many applications involving induction motors that are controlled using variable frequency drives require the ability to stop quickly. These applications include emergency stops, quick stopping of fans, centrifuges, presses, etc. The technique that is widely accepted in the industry for achieving quick stopping makes use of brake resistors in series with a power semiconductor switch. The switch-resistor combination (brake-unit) is applied across the dc bus. The fastest decelerating time achievable depends on the size of the resistors and the switch employed. In this paper, the authors propose a novel method of achieving quick stopping times without the use of any brake-unit. Experimental test results with and without this method on a large inertia motor-load combination show that the proposed stopping method is able to reduce the stopping time significantly compared to normal decelerated stop without the need for a braking unit.

• 대한산업공학회지
• /
• 제30권4호
• /
• pp.267-276
• /
• 2004

Much of previous attention on researches of the decision tree focuses on the splitting criteria and optimization of tree size. Nowadays the quantity of the data increase and relation of variables becomes very complex. And hence, this comes to have plenty number of unnecessary node and leaf. Consequently the confidence of the explanation and forecasting of the decision tree falls off. In this research report, we propose some decision tree algorithms considering the interaction of predictor variables. A generic algorithm, the k-1 Algorithm, dealing with the interaction with a combination of all predictor variable is presented. And then, the extended version k-k Algorithm which considers with the interaction every k-depth with a combination of some predictor variables. Also, we present an improved algorithm by introducing control parameter to the algorithms. The algorithms are tested by real field credit card data, census data, bank data, etc.

• 한국멀티미디어학회논문지
• /
• 제7권12호
• /
• pp.1700-1707
• /
• 2004

Nowaday, market size of digital image in world around is looks to rapidly growth. For this, Texture mapping has traditionally been used to add realism to computer graphics images. Therefore to make our image realistic, we need to give the various kind of objects material parameter and environment lighting. To present the completed marble we use passing back algorithm and combination with channel of a material. In experimental result of this paper that application by passing back algorithm and varying the parameter such as scale, period, distortion, octaves of noise make showing the superiority of optimized rendering of spheres and perfect another marble effects.

• 한국분말재료학회지
• /
• 제9권4호
• /
• pp.203-210
• /
• 2002

A new PIM in-process joining technique has been developed for more complicated and functional PIM components by application of the exuded wax from the green compacts during solvent debinding step. At first, various stainless steels and iron compacts with rectangular shape were combined, and the joining behaviors and properties were investigated by shear and tensile test, and microscopic observation. Subsequently, perfect joined three pieces of thin and hollow compacts were obtained for the combination of same and different stainless steels, and it was difficult to join the iron and stainless steel compacts in hydrogen atmosphere because of the different starting temperature of shrinkage. However, pretty good joined iron and stainless steel compacts were obtained by consideration of particle size and vacuum atmosphere. Finally, for the combination of ferro-silicon and austenitic stainless steel compacts, high functionality (magnetic (1.60Tes1a) & non-magnetic) and perfect joint were obtained.

• Structural Engineering and Mechanics
• /
• 제35권5호
• /
• pp.539-554
• /
• 2010

Light weight superstructure is beneficial for bridges in remote areas and in emergency erection. In such weight sensitive applications, combination of fibre reinforced plastics (FRP) as material and box-girders as a structural system have great scope. This combination offers various options to tailor structure and its elements but this flexibility poses greater challenge in optimum design. In this paper a procedure is derived for a generalised optimum design of FRP box-girder bridges, using genetic algorithms (GA). The formulation of the optimum design problem in the form of objective function and constraints is presented. Size, configuration and topology optimization are done simultaneously. A few optimum design studies are carried out to check the performance of the developed procedure and to get trends in the optimum design which will be helpful to the new designers.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
• /
• pp.96-99
• /
• 2004

The combination of mechano-chemical activation and Self-propagating High-temperature Synthesis (SHS) has widened the possibilities for both methods. For YBCO systems the investigation showed that a short-term mechano-chemical activation of initial powders before SHS leads to single-phase and ultra-fine products. A new technique for preparation ultra-fine high-temperature superconductors of YBCO composition with a grain size d ＜1 ${\mu}{\textrm}{m}$ is developed. The specific feature of the technique is formation of the YBa$_2$Cu$_3$O$_{7-{\delta}}$ crystalline lattice directly from an X-ray amorphous state arising as a result of mechanical activation of the original oxide mixture. The technique allows the stage of formation of any intermediate reaction products to be ruled out. X-ray and magnetic studies of ultra-fine high temperature superconductors (HTS) are carried out. Dimension effects associated with the microstructure peculiarities are revealed. A considerable enhancement of inter-grain critical currents is found to take place in the ultra-fine samples.fine samples.

• International Journal of Computer Science & Network Security
• /
• 제21권7호
• /
• pp.324-330
• /
• 2021

Agriculture is one of the essential needs of human life on planet Earth. It is the source of food and earnings for many individuals around the world. The economy of many countries is associated with the agriculture sector. Lots of diseases exist that attack various fruits and crops. Apple Tree Leaves also suffer different types of pathological conditions that affect their production. These pathological conditions include apple scab, cedar apple rust, or multiple diseases, etc. In this paper, an automatic detection framework based on deep learning is investigated for apple leaves disease classification. Different pre-trained models, VGG16, ResNetV2, InceptionV3, and MobileNetV2, are considered for transfer learning. A combination of parameters like learning rate, batch size, and optimizer is analyzed, and the best combination of ResNetV2 with Adam optimizer provided the best classification accuracy of 94%.