• 한국공작기계학회논문집
• /
• 제13권5호
• /
• pp.49-54
• /
• 2004

In order to evaluate the stability of chatter vibration in turning precess, the micro-positioning cutting test with artificial tool vibration by piezoelectric actuation were carried out. In experiment, the phase lags between cutting forces and chip thickness variations were measured, and the dimensionless penetration-rate coefficient（$\overline{K^*}$） which is the most important parameter on the stability for chatter vibration was calculated. The results show that$\overline{K^*}$ can be applicable to the stability criterion for regenerative chatter vibration.

• 전기학회논문지
• /
• 제61권11호
• /
• pp.1720-1724
• /
• 2012

This study describes an oscillometric-based blood pressure measuring algorithm by detecting turning points of oscillation signal from digitally filtered cuff signals of an automatic sphygmomanometer. The blood pressure measuring algorithm uses a characteristic ratios method from the turning points. The accurate values of the systolic/diastolic blood presures(SBP/DBP) are calculated using the peaks in the ranges of characteristic ratios. Performances of the proposed algorithm and four automatic sphygmomanometers are compared with the mercury manometer(manual type sphygmomanometer), regarding the SBP and DBP values of manual sphygmomanometer as the reference values. The performance test showed the proposed algorithm revealed the best results in errors and a statistical analysis. Therefore this algorithm can be usable in any automatic sphygmomanometers.ssure states. This may be compromising results for subject-independent sensibility evaluation using EEG signal.

• 한국생산제조학회지
• /
• 제7권2호
• /
• pp.29-39
• /
• 1998

A conversational programming system for turning processes was studied to enhance the user friendliness of a NC Lathe by adopting man-machine interface functions through Delphi programming tool under the Windows 95 environment. Functions of tool collision checking were developed through zone limitation algorithms. Final shape of workpiece was generated by means of tree structure algorithm. Shop floor programming performance was incorporated in the developed CAM module. In order to increase flexibility of the man-machine interface, graphic based programming tools have been developed. A NC turning machine equipped with an open architecture PCNC was used as a test bed of the system. Performance of the system was verified through case studies.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
• /
• pp.11-15
• /
• 1999

Monitoring of the cutting force signals in cutting process has been well emphasized in machine tool communities. Although the cutting force can be directly measured by a tool dynamometer, this method is not always feasible because of high cost and limitations in setup. In this paper an indirect cutting force monitoring system is developed so that the cutting force in turning process is estimated based on a AC spindle drive model. This monitoring system considers the cutting force as a disturbance input to the spindle drive and estimates the cutting force based on the inverse dynamic model. The inverse dynamic model represents the dynamic relation between the cutting force, the motor torque and the motor power. The proposed monitoring system is realized on a CNC lathe and its estimation performance is evaluated experimentally.

• 한국공작기계학회논문집
• /
• 제10권5호
• /
• pp.31-38
• /
• 2001

This paper deals with the micro turning property of setting angle using diamond tool. The bed of the system has used the granite which has the thermal and vibrational characteristics superior to the cast iron bed for the common machine tool. To minimize the inner and outer vibration of the fuming system, an air pad system was manufactured and tested. The aero-static spindle system which has the excellent rotation accuracy was designed and manufactured. As a result of the micro-cutting test on aluminum alloy, tool setting angel have effected on surface roughness. From the results, the micro-cutting conditions hope to provide the useful actual data using in industrial fields.

• 한국생산제조학회지
• /
• 제18권6호
• /
• pp.675-680
• /
• 2009

Because of high specific stiffness, the aluminum alloy has been used for various industry field. Specially, the heat-treated aluminum alloy is difficult-to-machine material and machining test is necessary to evaluate and improve the machinability. In order to manufacture the functional part, appropriate cutting condition is selected by considering surface quality, machining time, and workpiece deflection by cutting force. In this investigation, the machinability of A16061-T6 is estimated by changing cutting conditions. The variable cutting conditions are cutting speed, depth of cutting, and feed rate. The estimation is done by analysis of cutting force, surface roughness, and surface shape according to the change of cutting conditions.

• 한국안전학회지
• /
• 제25권2호
• /
• pp.89-94
• /
• 2010

This study deals with the traffic accident according to the improvement projects of frequent accident locations. The objective is to analyze the impact of improvements on the accident reduction. In pursuing the above, the study gives the particular attentions to developing the models based on the data of 70 intersections improved. The main results analyzed are as follows. First, 4 multiple linear regression accident models(total, side right-angle, rear end and side stripe accident) which were statistically significant were developed. Second, total accidents reduction by sight-distance and turning traffic flow improvements, side right-angle by sight-distance, over-speed and lane operation, rear end by turning traffic flow, signal and lane operation, and side stripe by traffic impedance improvements were analyzed. Finally, the above 4 models were evaluated to be statically significant through the correlation analysis and pair-sample t-test.

• Journal of Biosystems Engineering
• /
• 제17권3호
• /
• pp.213-222
• /
• 1992

To develop the wireless remote opreating system of walking rice transplanter, this study was carried out for manufacturing the wireless remote control system acting upon the transplanter. The first report of this study contained about the construction and operating method of a developed remote control system for 2-row walking type transplanter. It is the second report about the field test for an experimental transplanter being attached a wireless control system and for a conventional transplanter. The test was executed to investigate the characteristics of velocity, rectilinearity, turning time, interval of roots and of rows, and field capacity in accordance with various engine speeds for an experimental transplanter. The measurements of this test were compared with those of the conventional transplanter. The obtained results were as follows : 1. The operating velocity of the experimental transplanter was faster than the conventional one when the high speed range of the engine but the variances were very large. 2. The rectilinearity, interval of raws and of roots, and the turning time of the experimental transplanter was inferior to the conventional one at some speed ranges of the engine. 3. Field capacity of the experimental transplanter was superior to the conventional one at high speed of the engine. 4. There were some disadvantages for the experimental transplanter to operate, because it was constructed without any aid devices, such as float and hydraulic system for instance. But if the remote control system of this study equip at the modern walking transplanter, it will be improved and utilized without defects which was revealed from this test.

• 한국수산과학회지
• /
• 제12권4호
• /
• pp.209-215
• /
• 1979

부산수산대학실습선 '새바다'(GT: 2,275.7ton)에 관한 조종성능을 구명하기 위하여, 실선에 의한 Z 조종시험을 한 결과를 요약하면 다음과 같다. 1. '새바다'호의 $10^{\circ}Z$시험에서의 선회성지수 K'값은 1.052, 추종성지수 T' 값은 0.815, $20^{\circ}Z$ 시험에서의 K'값은 0.925, T'값은 0.502, $30^{\circ}Z$ 시험에서의 K' 값은 0.877, T' 값은 0.441로서, 소타각사용시의 조종성능과 대타각사용시의 조종성을 비교하여 보면, 대타각을 사용할 때 보다 추종성을 좋아지나 선회성을 낮아진다는 것을 알 수 있다. 2. '새바다'호의 $10^{\circ}Z$ 시험에서의 선회성지수 K' 값과 추종성지수 T' 값은 어선의 표준식에 가까움으로 어선으로서 양호한 조종성능을 가지고 있다고 볼 수 있었다. 다만 길이와 크기에 비하여 K'값이 약간 적은 수치이며, $10^{\circ}Z,\; 20^{\circ}Z,\;20^{\circ}Z$ 시험에서의 회두각곡선의 overshoot angle이 약간 크므로 추종성은 좋으나 선회성은 낮은 편임을 알 수 있었다. 3. '새바다'호의 조종성능은 추종성에 비하여 선회성이 낮으므로 선회경도 크게 되며, 또한 대각도전타시에 비하여 선회성이 낮아지므로, 충돌이나 좌초를 회피하기 위하여 대각도전타를 할 경우에는 안전한게 접근거리를 크게 두어 한기전타하는 등 조선상주의를 요한다. 4. '새바다'호의 $10^{\circ}$시험에서의 1조작간항주거리하는 배 길이의 약 8.6배로서 일반선박의 조종성표준거리 $5\~11$배의 이내가 되므로 '새바다'호의 조종성능은 총합적으로 양호하다는 것을 알 수 있었다.

• 대한조선학회논문집
• /
• 제49권4호
• /
• pp.296-303
• /
• 2012

The captive model test of submerged body using CPMC(Computerized Planar Motion Carriage) was carried out at the Ocean Basin of KORDI/MOERI. The target model is a submarine with general hullform. The forces and moments acting on the submerged body were measured by 6-axis waterproof gage. The oblique motion test and turning test were carried out in horizontal and vertical planes of the model. Maneuvering coefficients and derivatives were obtained from the test results. The stability indices in horizontal and vertical planes were obtained by using maneuvering derivatives. In this paper the introduction of test equipment and test results are presented.