• Reproductive and Developmental Biology
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• 제32권4호
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• pp.249-253
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• 2008

Interspecies somatic cell nuclear transfer (iSCNT) is a valuable tool for studying the interactions between an oocyte and somatic nucleus. The object of this study was to investigate the developmental competence of in vitro-matured porcine oocytes after transfer of the somatic cell nuclei of 2 different species (goat and rabbit). Porcine cumulus oocytes were obtained from the follicles of ovaries and matured in TCM-199. The reconstructed embryos were electrically fused with 2 DC pulses of 1.1kV/cm for $30{\mu}s$ 0.3M mannitol medium. The activated cloned embryos were cultured in porcine zygote medium-3 (PZM-3), mSOF or RDH medium for 7 days. The blastocyst formation rate of the embryos reconstructed from goat or rabbit fetal fibroblasts was significantly lower than that of the embryos reconstructed from porcine fetal fibroblast cells. However, a significantly higher number of embryos reconstructed from goat or rabbit fetal fibroblasts cultured in mSOF or RDH, respectively, developed to the morular stage than those cultured in PZM-3. These results suggest that goat and bovine fetal fibroblasts were less efficacious than porcine-porcine cloned embryos and that culture condition could be an important factor in iSCNT. The lower developmental potential of goat-porcine and porcine-bovine cloned embryos may be due to incompatibility between the porcine oocyte cytoplasm and goat and bovine somatic nuclei.

• 한국분말재료학회지
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• 제24권3호
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• pp.202-209
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• 2017

A cold-work tool steel powder is used to fabricate 3-dimensional objects by selective laser melting using a high-pressure gas atomization process. The spherical powder particles form continuous carbide networks among the austenite matrix and its decomposition products. The carbides comprise Nb-rich MC and Mo-rich $M_2C$. In the SLM process, the process parameters such as the laser power (90 W), layer thickness ($25{\mu}m$), and hatch spacing ($80{\mu}m$) are kept fixed, while the scan speed is changed from 50 mm/s to 4000 mm/s. At a low scan speed of 50 mm/s, spherical cavities develop due to over melting, while they are substantially reduced on increasing the speed to 2000 mm/s. The carbide network spacing decreases with increasing speed. At an excessively high speed of 4000 mm/s, long and irregularly shaped cavities are developed due to incomplete melting. The influence of the scan pattern is examined, for which $1{\times}1 mm^2$ blocks constituting a processing layer are irradiated in a random sequence. This island-type pattern exhibits the same effect as that of a low scan speed. Post processing of an object using hot isostatic pressing leads to a great reduction in the porosity but causes coarsening of the microstructure.

• 한국축산시설환경학회지
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• 제19권1호
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• pp.63-68
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• 2013

In vitro culture and radiation techniques were used for obtaining mutants tin tall fescue. Endophyte free and friendly tall fescue cultivars Kentucky-31 and Jesup were used for induction of genetic variability through in-vitro mutagenesis. Mature seeds was used for callus induction on 6 mg/L 2,4-D. Actively growing and compact callus was treated with three different doses of gamma rays (10 Gy, 30 Gy and 50 Gy). Maximum proliferation and plantlets regeneration growth was observed in control and minimum at 10 Gy. Furthermore, the maximum number of tiller in the irradiated population was observed in 10 Gy. The treatments 30 Gy and 50 Gy exhibited negative impact on the tillering potential of the tall fescue plant. The object of this study was to develop protocols for mutation breeding in tall fescue through radiation techniques.

• 상하수도학회지
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• 제30권6호
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• pp.707-714
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• 2016

In order to prevent secondary pollution of tap water, corrosion characteristics are investigated, and corrosion index are calculated using LI and LR to manage corrosiveness. As targeted water treatment plants from 2014 (July, once) to 2015 (July and October, 2 times), 70 plants are selected by making a division for each area and water system. (treated water samples, n=240, raw water samples, n=72). In result of pH analysis, treated water was lower than raw water to 7.12, and 7.29, respectively. LI were investigated in the order of Seomjin river, Nakdong river, Han river, Geum river, to -2.08, -1.24, -1.11, -1.10 (at raw water), and -2.18, -1.59, -1.51, -1.35 (at treated water), respectively. In case of water quality goal value (LI = -1) in Japan as control of corrosiveness, management object was investigated about 83.3%.

• 한국해양공학회지
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• 제21권2호
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• pp.42-49
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• 2007

It has been known that shallow-water regions, such as tidal flats, sea grass and sea weed beds have water purification capability, and they also serve as nursery grounds for many fishes. On the other hand, tidal flat areas are economically attractive sites for reclamation, to be used for developing industries. When developing shallow-water areas, we have to propose a plan to mitigate the environmental impact associated with such a development plan. However, it is difficult to estimate the affects on the ecosystem and water purification, and the literature related to this matter is insufficient. In order to evaluate the ability of coastal tidal flat and to predict the future changes, it is necessary to develop a reliable prediction technique and construction of data by using a field investigation. In this study, we carried out a numerical model test for the tidal flat ecosystem, using the pelagic system and the benthic system, simultaneously, in order to show a change in the tidal flat ecosystem. The flow of nitrogen, phosphorus and carbon has been identified as a primary consideration of marine ecosystem components, and the capability of water purification and the change of the tidal flat were predicted using this flow. In order to make a more reliable prediction, a field investigation to determine tide, current and creatures of the object coastal area has been done. The purification capability of this shallow-water region is estimated from the model results. According to the results of experiments, the tidal flat has a capability of water purification (Sink) of 11mgN/m2/day, but the other area has a load (Source) of 20mgN/m2/day. As a result, we could confirm that the tidal flat of an object coastal area plays an important role in water purification.

• 한국게임학회 논문지
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• 제15권5호
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• pp.29-38
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• 2015

본 연구는 모바일 RPG에서 게임 시스템으로 삽입된 자동전투 기능의 플레이어 욕망 충족 양상을 살펴보고자 한다. 이를 위해 먼저 자동전투의 유형을 활성화 시점과 플레이어 개입 정도를 기준으로 '부분적 자동전투'와 '완전 자동전투'로 분류한다. 이후 유형별 플레이 양상을 도출하여, 플레이어의 욕망의 대상을 라캉(Lacan)의 욕망이론을 바탕으로 살펴보았다. 이를 통해 부분적 자동전투에서 플레이어는 완벽한 조작을 통해 더욱 높은 단계를 공략하고 싶은 욕망을 가지고 있었으며, 욕망의 대상은 전투지의 난이도가 된다. 반면 완전 자동전투에서의 플레이어는 게임의 규칙을 완벽하게 이해하고, 전투지 공략 이후 획득할 수 있는 보상을 통해 더욱 강력한 캐릭터를 가지고 싶은 욕망을 가진다. 플레이어가 욕망의 대상을 획득하고 나면 그것이 허상이었다는 것을 알게 되고 새로운 욕망의 대상을 찾아 추구하게 된다. 이 과정에서 자동전투는 욕망의 대상을 획득하려는 주체의 적극적인 행위로서 사용된다.

• Journal of Advanced Marine Engineering and Technology
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• 제39권5호
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• pp.570-576
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• 2015

3D visualization of navigation simulation is to visualize the environment conditions (e.g. nearby ships, dynamic characteristics, environment, terrain, etc) for any users on ships at sea. Realistic 3D visualization enables the users to be immersed to it and guarantees the reliability of the simulation. In particular, terrain visualization contains many virtual objects, so it is time and cost-intensive for object modelling. This paper proposes a 3D terrain visualization method that can be realized in a short time and with low cost by using the Unity 3D development tool. The 3D terrain visualization system requires bathymetric and elevation terrains, and Aids to Navigations (AtoNs) to be realized. It also needs to include 3D visualization objects including bridges, buildings and port facilities for more accurate simulation. Bathymetric and AtoN elements are acquired from ENC, and the elevation element is acquired from SRTM v4.1 digital elevation chart database developed by NASA. Then, the bathymetric and elevation terrains are generated, and the satellite images are superposed by using this terrain information. The longitudinal and latitudinal information of the AtoNs are converted to the 3-axis information to position the AtoN locations. The 3D objects such as bridges, buildings and port facilities are generated and the terrain visualization is completed. The proposed method realizes more realistic 3D terrain visualization of Busan Port.

• International Journal of Control, Automation, and Systems
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• 제6권3호
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• pp.453-459
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• 2008

The neural network is currently being used throughout numerous control system fields. However, it is not easy to obtain an input-output pattern when the neural network is used for the system of a single feedback controller and it is difficult to obtain satisfactory performance with when the load changes rapidly or disturbance is applied. To resolve these problems, this paper proposes a new mode to implement a neural network controller by installing a real object for control and an algorithm for this, which can replace the existing method of implementing a neural network controller by utilizing activation function at the output node. The real plant object for controlling of this mode implements a simple neural network controller replacing the activation function and provides the error back propagation path to calculate the error at the output node. As the controller is designed using a simple structure neural network, the input-output pattern problem is solved naturally and real-time learning becomes possible through the general error back propagation algorithm. The new algorithm applied neural network controller gives excellent performance for initial and tracking response and shows a robust performance for rapid load change and disturbance, in which the permissible error surpasses the range border. The effect of the proposed control algorithm was verified in a test that controlled the speed of a motor equipped with a high speed computing capable DSP on which the proposed algorithm was loaded.

• 대한인간공학회지
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• 제30권1호
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• pp.229-235
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• 2011

Objective: Making a new ergonomic interface system based on camera vision system, which helps the handicapped in home environment. Background: Enabling the handicapped to manipulate the consumer electronics by the proposed interface system. Method: A wearable device for capturing the eye image using a near-infrared(NIR) camera and illuminators is proposed for tracking eye gaze position(Heo et al., 2011). A frontal viewing camera is attached to the wearable device, which can recognize the consumer electronics to be controlled(Heo et al., 2011). And the amount of user's eye fatigue can be measured based on eye blink rate, and in case that the user's fatigue exceeds in the predetermined level, the proposed system can automatically change the mode of gaze based interface into that of manual selection. Results: The experimental results showed that the gaze estimation error of the proposed method was 1.98 degrees with the successful recognition of the object by the frontal viewing camera(Heo et al., 2011). Conclusion: We made a new ergonomic interface system based on gaze tracking and object recognition Application: The proposed system can be used for helping the handicapped in home environment.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5849-5855
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• 2011

애플리케이션 소프트웨어 개발 환경이 빠르게 변함에 따라 사용자 인터페이스 설계의 중요성이 증가하고 있다. 일반적으로 대부분의 설계자들은 설계 인터페이스에서 상호 의존성 있는 객체들을 정의하기 위해 개인 각자의 주관적인 방법으로 그룹화한다. 그러나 특정한 규칙이 배제된 체 설계된 인터페이스는 이러한 시스템을 사용하는 사용자들에게 업무의 비효율성과 복잡성만 증가시킬 뿐이다. 그러므로, 본 논문에서는 인터페이스 프로토타입을 정형화 함으로써 어떠한 GUI 환경에서도 유연한 개발을 할 수 있도록 객체지향 설계 모델을 제안한다. 사용자 인터페이스의 가시적 응집도는 사용자 인터페이스 내용들과 연관된 연구를 해왔던 새로운 범주영역이며, 기본적 소프트웨어 공학 개념을 사용하는 것을 정의한 것으로서 인터페이스의 응집 원리에 기반한다. 가시적 응집도는 프로그래밍 단위로 나타나는 비즈니스 이벤트의 응집도 뿐 아니라 각 단위 객체가 정렬되고 그룹화되는 방법에 대한 결과를 내포한다. 따라서 인터페이스는 비즈니스 이벤트들이 상호 연관성으로 그룹화 된다면 이해하기 쉽고 사용하기가 더욱 용이해질 것이다.