압력유도연성(Pressure-lnduced Ductility) : 금속성형공정에서의 가장 중요한 인자는 가공물의 연성이다. 금속학적인 측면에서의 연성이란 실온에서 측정되는 것이며 가장 일반적인 연성연성측정방법은 인장시험이다. 금속재료의 연성을 증가시키기 위한 보통의 방법은 가열이며 대부분의 경우 가열된 재료는 보다 연하게 되므로, 보통가열은 변형한도를 증가시키고 성형력을 줄이기 위해 사용되어 왔다. 그 런데 Bridgman은 금속의 연성이란 금속학적 성질 뿐 아니라 주변압력이라는 기계적 방법에 의해서도 조정될 수 있다는 것을 지적하였다. 그는 응력-연신률 선도에서 얻어진 금속의 연성은 정수압을 가함으로써 증가될 수 있다는 것을 보였다. 중간응력, 평균응력, 정수압 응력, 정수압 압력, 주변압력 등의 용어가 같은 의미로 사용되어진다. 재료의 금속학적성질 뿐 아니라 공정의 압력도 변수로 작용하여 성형성을 개선시키게 되는데 이런 현상을 압력유도연성(PID)은 주변압력이 재료내부에서의 공동발생 및 그 성장을 억제하기 때문에 얻어진다. 공동 의 합체 및 성장은 연성파괴의 전제조건이 되므로 이러한 현상이 발생되지 않도록 하면 성형성 및 연성이 증가된다. 공동의 형성 및 예방 과 인장봉의 강도와 변형에 미치는 압력효과의 수학적 해석은 참고문헌 2에 나타나 있다. 이 압력유도연성은 Bobrowsky, Pugh와 Green, Alexander등에 의해 확인되었다.

Servo의 안정성: Servo는 정상상태, 과도상태의 특성을 문제삼기에 앞서 먼저 안정하지 않으면 안된다. 제어량과 제어편차와 같이 제어 loop 속의 신호가 일정치에 수검하지 않는 현상을 불안정이라 한다. 제어량의 feedback을 정(positive)으로 하며 일반 목표치에는 수검하지 않고 제어편차는 단조롭게 정, 또는 부(negative)의 방향으로 발산한다. 이것은 접속 잘못에 의한 이상현상에 속한다. 이것에 대해서, 부 feeeback으로 하여도 제어 량이 목표치에 수검하지 않고 지속적으로 진동하는 불안현상도 있다. 이들은 선형발진과 비선형발진으로 구분할 수 있다.

Opto-electronics의 의학에의 응용: 전자공학과 광학의 결합산물인 광전자공학긔 의학응용은 진단,치료에 새로운 경지를 열어주게 되었다. 계측진단은 검체에 적용하는 것과 생체에 적용하는 것으로 분류되어진다. 검체에 적용하는 것은 주로 INVITRO 계측으로 생화학분석, 전기영동, 자동혈구계수등이다. 생체에 적용하는 INVIVO 계측은 관찰, 계측용의 내구경과 비관혈계측으로 분광분석, 산소포화도등의 광의 투과율계측, 적외.마이크로파 .thermography와 같은 방사계측, 발색량계측 등이 이에 속한다. 또한 광전자공학을 응용하여 병원애 전송네트워크구성, 광통신등도 최근의 활용과제중의 하나다. 특히 광전자공학의 응용중에서 가장 관심의 대상이 되는것은 치료에의 응용이다. 그러므로 여기서는 이들 응용중에서 가장 유용성이 있는 적외선 thermography와 Laser의 응용에 대해 간단히 기술하기로 한다.

In this study, to check up on the effect of the components of cutting resistance upon friction between drill and inside wall of hole in drilling, the experiment was performed with individual specimen of carbon steel, cast iron, aluminium alloy under various cutting conditions: depth of hole, cutting speed, feed rate, shape and material of specimen. On the basis of the experimental results, the following conclusions are drawn; 1. The components of cutting resis- tance were increased in proportion to the increase of depth of hole owing to frictional resistance of drill margin and chip-jamming. 2. As feed rates increase, torque and thrust were increased. When comparing to the increasing rate for these components respecitively, thrust is higher tendency than torque. 3. As drill diameter increase, torque and thrust were increased. When comparing to the increasing rate for these components respectively, torque is higher tendency than thrust. 4. In the case of torque, the frictional resistance between drill margin and inside wall of drilled hole accounts for about 20 percent of carbon steel, 14 of cast iron, 10 aluminium alloy in drilling. But the effect of thrust force could be negligible. 5. Comparison between the theoretical and experimental results showed a close agreement so far as depth of hole is about three times of drill diameter. But there was a wide difference between them beyond the rane of three times, because of characteristics of the drilling process.

The behavior of the burn-on in sand mold has been investigated by varying the pouring metal, bonding materials, additive materials and molding sand. The results obtained from thease experiments are as follows; 1) The burn-on layer of silica sand decreased in order of carbon steel, gray cast iron and stainless steel, and thease burn layer proceeded mostly by producing FeO. 2) The burning reaction of silica sand mold in carbon steel castings declined with increasingly bentonite content, but water-glass scarcely took part in the burn-on reaction. 3) The addition of feldspar and seacoal to silica sand promoted the inhibiting burn-on. 4) The burn-on layer of sand mold decreased of silica sand, chromite sand and olivine sand.

The study is concerned with the analysis of the required loads and torque in the Three-Roll Power Spinning Process by using the Method of Force Polygon Diagram. Experiments are carried out using pure lead billets at room temperature. The radial force, the axial force and the torque occurring during the process are calculated theoretically and are compared with the experimental data. An approximate load distribution is known by the Force Polygon Diagram.

The purpose of this paper is to investigate the variations of out-of- roundness due to its assessment methods for the practical workpieces. Experiments were carried out with the test specimens having the typical roundness profile. The roundness measuring system which has the autocentripetal functions and the automatic centering table unit was used. From the experimental results, it was found that the ratio of LSC to MZC values varied with the shape of roundness profiles, and the rate of variation for out-of-roundness was increased logarithmically with the increment of undulations by the effect of filter. Therefore, it is suggested that the least squares center method should be useful with the sufficient accuracy except for some special cases in the roundness profiles, and the condition of filter has considerable influence upon the out-of-roundness to be measured.

A four-bar mechanism in consideration of the tolerances on link lengths and the clearances in joints is optimally designed by the method of stochastic analysis. The random nature of clearances and tolerances establishes a stochastic optimization design equation in which the parameters in the equation are described by random variables. In order to solve the design equation, the stochastic problem is converted into an equivalent deterministic one. The synthesis of four-bar mechanism for minimum mechanical and structural errors is carried out by the optimization techni- ques using Chebyshev spacing of precision points. By the results from the synthesized mechanism, the generated and desired motions are examined.

Adaptive control technique for a milling process is developed and implemented in an NC milling machine retrofitted to enable the micro-computer control. The control algorithm has the objects to guarantee the optimal tool life which can give the predetemined allowable lower limit of surface roughness. The experimental results show 1) that the extended tool life equation has good reliability in normal tool wear conditions. 2) and that the proposed adaptive control technique, which determine the optimal cutting condition by basing on the tool life equation modified continually according to the tool wear measured in real time, performs well.

This paper proposes the theory for the Low Cost Automation (LCA) as a intermediate process of the factory automation, where the SCA is new adaptation for the improving productivity without changing the current product lines. And also this paper deals with the case study for the predictable effects and technical method at the extruding cable lines. As the results, the implementation of the LCA theory could be acomplished saving materials and man power, improving reliability and productivity. For this facilities, it cost within 5% extra expense of a extruding cable line systems. And it could be refund in six months.