• 한국잠사곤충학회지
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• 제16권2호
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• pp.119-125
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• 1974

정상잠이 3령의 성식기에 이르렀을때(춘잠기 소잠후약 9일 20시간 경과한 무렵) 불면잠으로 인정되는 것과 같은 잠박에서 정상잠을 재료로 하여 이를 고정하였고 또한 4령의 성식기에 1~2령기의 발육정도 밖에 되지 않은 왜소잠을 수집하여 고정하고 이와 동시에 이때의 정상잠도 고정하였다. 불면잠과 정상잠을 형태학적으로 비교하고 그 조직검사에서 얻은 조사내용을 요약하여 보면 다음과 같다. 1. 정상잠이 3령의 성식기에 이르렀음에도 불면잠으로 인정되는 누에는 마치 소잠후 2일이 경과한 정도의 누에의 크기에 불과하였으며 4령의 성식기에 관찰한 불면잠도 이와 대동소리라하였다. 2. 태피선은 타원형의 편평한 낭상체로서 그 크기는 흉부에 위치하는 것이 작고 복부의 것이 일반적으로 큰 경향을 나타냈다. 3. 흉부에 있는 태피선은 흉지의 기부에 있는 것이 배맥관을 끼고 있는 태피선보다 큰것으로 종내에는 보고되었지만 본실험결과에 었어서는 일정한 경향이 없었다. 4. 정상잠이 3령의 성식기에 이르렀을 때의 태피선의 크기는 전흉에 있는 것이 최소로서 151.3$\mu$(major axis)~94.5$\mu$(minor axis)였고 최대로서는 복부제7절의 것이 568.6$\mu$~495.$\mu$였으며 이때에 불면잠으로 인정되는 것은 최소로서 전흉에 있는 태피선이 57.5~51.3$\mu$이였으며 최대로서는 복부제5절의 것이 91.5~75.5$\mu$으였다(표 1. 참조) 5. 정상잠이 4령의 성식기에 이르렀을 때 정상잠과 왜소잠의 태피선의 크기를 비교해 본 바에 의하면 정상잠에 있어서는 전흉의 것이 최소로서 252.2~131.6$\mu$이였고 복부제7절의 것이 최대로서 691.5~493.4$\mu$이였으며 왜소잠에 있어서는 후흉의 것이 최소로서 71.4~61.5$\mu$이였고 복부제8절의 것이 최대로서 94.6~71.5$\mu$이였다(표 2. 참조) 6. 불면잠에 있어서의 태피선의 형태는 그 공포형태피선이 정상잠의 것과 크게 차이가 있어 공흉의 크기가 정상잠의 것에 비하여 몇배에 달하였다. 7. 불면잠과 정상잠과의 분필세포의 구조에는 큰 차이가 없지만 불면잠의 과립형태피선은 정상잠에 비하여 소형이 었다.

• 대한치과보철학회지
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• 제14권1호
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• pp.11-16
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• 1976

Casts are often transferred to the articulator by arbitrary means, because the method of locating the true hinge axis point thought to be a complicated and time consuming procedure, and because the importance and significance of the true hinge axis in the construction of dental prosthesis is not sufficiently understood. In this report, the author constructed the hinge axis locator and determined the variations in location of the true hinge axis points from the location of the hinge axis point determined by arbitrary means. For this report, the procedure was followed on 50 persons with normal occlusion and sound T.M.J. function, so 100 true hinge axis points were recorded and compared with the arbitrary hinge axis point. The results obtained were as follows. 1. The mean distance from the arbitrary hinge axis point to the true hinge axis point was as follows. Right; (O)5.17mm., (V)3.44mm., (H)3.55mm.. Left; (O)5.63mm., (V)3.95mm., (H)3.51mm.. 2. The percentage of true hinge axis points classified at intervals of 2mm was as follows. 0-2mm; 4%, 2-4mm; 21%, 4-6mm; 37%, 6-8mm; 26%, 8-10mm; 10%, Over 10mm; 2%. And only 50% of the 100 true hinge axis points were located within a 5mm. radius of the arbitrary hinge axis point. 3. Instead of transferring the casts to the articulator by arbitrary means, the careful location of the true hinge axis points is recommended to avoid potential sources of error in mounting casts.

• 한국CDE학회논문집
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• 제15권5호
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• pp.354-361
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• 2010

The paper presents an efficient computation of optimal tool length for 5-axis mold & die machining. The implemented procedure processes an NC file as an initial input, where the NC data is generated by another commercial CAM system. A commercial CAM system generates 5-axis machining NC data which, in its own way, is optimal based on pre-defined machining condition such as tool-path pattern, tool-axis control via inclination angles, etc. The proper tool-length should also be provided. The tool-length should be as small as possible in order to enhance machinability as well as surface finish. A feasible tool-length at each NC block can be obtained by checking interference between workpiece and tool components, usually when the tool-axis is not modified at this stage for most CAM systems. Then the minimum feasible tool-length for an NC file consisting of N blocks is the maximum of N tool-length values. However, it can be noted that slight modification of tool-axis at each block may reduce the minimum feasible tool-length in mold & die machining. This approach can effectively be applied in machining feature regions such as steep wall or deep cavity. It has been implemented and is used at a molding die manufacturing company in Korea.

• 대한치과보철학회지
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• 제22권1호
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• pp.72-78
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• 1984

The notion that the axis of the shaft of the articulator must coincide the patient's mandibular transverse axis tells us the importance of locating the axis precisely. When using kinematic axis to transfer a cast to an articulator, the anatomic asymmetry of the contralateral points will result in certain distortion when the axis transferred to an articulator where the mechanical axis produces symmetry. In this study, after locating the true hinge axis point with Denar hinge axis locator, the discrepancies between true hinge axis point and arbitrary hinge axis point that was 13mm anterior from the posterior margin of center of trangus to the outer canthus of eye were measured. And the discrepancies between left and right true hinge axis point in the superoinferior and anteroposterior directions were measured. For this study, 20 dental students who have no missing teeth and no difficulties of mandibular movement were selected. Upper and lower cast of subjects were mounted on Denar Mark II articulator uisng Denar Slidematic face-bow and centric relation record for the measurement of discrepancies between left and right true hinge axis points. The results obtained as follows. 1. The mean distance from the arbitrary hinge axis point to the true hinge axis point was as follows. Right: horizontal distance; 1.99mm, vertical distance; 2.12mm, linear distance; 3.36 mm. Left: horizontal distance; 1.39mm, vertical distance; 2.06mm, linear distance; 2.09mm. Total: horizontal distance; 1.69mm, vertical distance; 2.09mm linear distance; 3.06 mm. 2. The 87.5% of true hinge axis points were within 5mm of the arbitrary hinge axis point. 3. The mean discrepancies between the right and left hinge axis point were 2.92mm in superoinferior direction and 4.74mm in anteroposterior direction. 4. When transferring the axis to the articulator, anatomic asymmetry between right: and left axis point produces in dislocation of cast on the articulator, and undesirable shift in esthetic tooth position will be resulted.

• 한국정밀공학회지
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• 제31권5호
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• pp.431-439
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• 2014

Recently, a demand for precision 5-axis machine tools is significantly increasing, and the maintenance of machine tool accuracy becomes more important. it is very difficult to evaluate to accuracy of 5-axis M/C in the production site since it needs expensive measuring equipment and skilled engineer. On the other hand, evaluation items of 5-axis M/C are not systematically organized in the existing KS and ISO standards. In this study, the evaluation items for 5-axis M/C were derived systematically and a test workpiece was developed to evaluate the machine tool accuracy more easily. The error sources of machine tool can be estimated by machining and measuring of the test workpiece. The correlation between the machine tool accuracy and the accuracy of machined test workpiece was analyzed. As a result, the accuracy of machined test workpiece represented the accuracy of machine tool and the error sources very effectively.

• 한국기계가공학회지
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• 제20권11호
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• pp.30-35
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• 2021

In this study, a machine simulation system was built using the actual scale of an AC-type 5-axis machine tool for mold surface machining that can be used in applications, such as, modeling and machine building, stroke, and collision detection. The validity of the 5-axis machine simulation system was verified by performing tool path generation, post-processing, machine simulation, prototype motion simulation, and an actual cutting experiment. This entire process was intended to activate the 5-axis machining in mold surface machining.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.179-180
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• 2012

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.461-462
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• 2010

• 한국생산제조학회지
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• 제19권5호
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• pp.678-683
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• 2010

The drum cam with rotational follower is used to apply the ATC and index table of machine tools and it has the merit of minimizing the backlash. In general, to machine the drum cam with rotational follower, 5-axis CNC machine must be used and its kinematic principle must be included in modeling on CAM. So, the commercialized CAM software can't be applied to this machining of drum cam. Though some special software for machining drum cam was developed, it could be applied to special 5-axis CNC machine tools and the finish machining module was not applied. To solve this problem, this study includes the induction of the post processing algorithm for the rough machining of drum cam on several 5-axis CNC machine tools, type AC, AB and Be. The finish machining software will be treated in next study. A sample drum cam was machined on 5-axis CNC machine tool of AC type. The designed geometric profile of drum cam consist to the measured profile after machining well. This post processing algorithm for rough machining of the drum cam was clearly verified.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.175-180
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• 2000

This paper describes the method and the process for impeller machining on 5-axis CNC machining center. Also, The CAD/CAM software for the impeller post processing is developed. The software can be interfaced with Solid-works software for confirmation of the impeller shapes. In this study, blades on impeller is described from Ruled-surfaces between two Ferguson curves. In this study, using 5-axis NC part program obtained from the developed software, a sample impeller was machined on 5-axis CNC machining center. The machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades with Ruled-surfaces.