• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1992.10a
• /
• pp.302-306
• /
• 1992

To improve the productivity of NC drilling machine the tool path should be minimized. This paper describes a new heuristic practical algorithm to produce tool path for PCB drilling processes with a large scale and its experimental results are shown.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.651-652
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.17-18
• /
• 2009

• Journal of the Korea Society for Simulation
• /
• v.8 no.1
• /
• pp.77-88
• /
• 1999

There are two approaches to handle the Causality Error in parallel and distributed simulation. One approach is based on the conservative time synchronization and the other is the optimistic time synchronization. In this paper an efficient null message reduction method for the conservative time synchronization approach is suggested with the experimental results, which could improve performance of simulation and avoid deadlock situations.

• The Journal of the Petrological Society of Korea
• /
• v.14 no.4 s.42
• /
• pp.226-236
• /
• 2005

Using the concept of granite suite/supersuite we hierarchically divided the Triassic granites in South Korea which have spatio-temporally close relationships each other. Among the Triassic granites in the Okcheon belt (western Yeongnam massif), the Baegrok granite and the Jeomchon granite can be grouped into one suite, the Baegrok suite, whereas the Cheongsan granite into the Cheongsan suite. These two suites can be grouped again into a larger supersuite, the Baegrok supersuite, on the basis of the similarity in the source rocks and the contrasts in the petrographic and geochemical characteristics. Three Triassic granites in the Gyeongsang basin - the Yeongdeok granite, the Yeonghae granite, and the Cheongsong granite - can be grouped into the Yeongdeok suite, Yeonghae suite and Cheongsong suite, respectively. These three suites can be grouped again into a larger supersuite, the Yeongdeok supersuite, on the basis of the similarity in the source rocks and the contrasts in the petrographic and geochemical characteristics. Nd-Sr isotopic signatures for the Baegrok supersuite are quite distinct from those for the Yeongdeok supersuite, indicating that the source materials of each granitic magma were not identical. The source rocks for the Baegrok supersuite are thought to be a mixture of two crustal components of the Yeongnam massif, whereas those for the Yeongdeok supersuite to be a mixture of the depleted mantle with the crustal components of the Yeongnam massif. The fact that the two contemporaneous granite supersuites were derived from the different sources can be explained by the difference of the tectonic environments where the granitic magmas were produced.

• Economic and Environmental Geology
• /
• v.53 no.6
• /
• pp.645-654
• /
• 2020

We present the K-Ar age dating results of <0.1㎛ fraction of the selected fault rocks from the Yangsan fault in the Yeonghae area. Based on the mineralogical characterization, the <0.1㎛ fractions were mostly composed of 1Md illite polytype, or I-S interstratified mineral, which should be formed by fault activation. Therefore, we determined the timings of fault activation events by analyzing K-Ar age-dating for the <0.1㎛ fractions. Accordingly, the activation timings of Yangsan Fault in the Yeonghae area were determined as 45.5±1.1 Ma, 50.9±1.2 Ma, 58.2±1.3 Ma, 60.8±1.4 Ma, 65.3±1.6 Ma, 66.8±1.5 Ma, 67.1±1.5 Ma, and 75.1±1.7 Ma. These results indicate that at least 5-times of major fault events occurred in the Yangsan fault from late Mesozoic to Cenozoic Era. In the outcrop, age dating results tend to be younger age from the location of the oldest sample(75.1±1.7 Ma) toward to the both sides. From the results, it suggests that the fault activation extends from the location of oldest age saple to both sides. This geochronological research of the multiple fault activation ages for the Yangsan Fault will provide crucial information for establishing the tectonic evolution model in the southeastern part of the Korean Peninsula.

• Journal of Korean Institute of Industrial Engineers
• /
• v.20 no.3
• /
• pp.79-92
• /
• 1994

Surface mount technology has been evolving in the electronics industries. Efficient operation of surface mounters is closely related with the productivity of the electronic products. In this study, modeling and optimal algorithm for allocating feeders and sequencing mounting jobs in the rotary type surface mounter, which consider all the constraints, in the hardware and are easy to be used in the field, are developed.

• The Journal of the Korean dental association
• /
• v.13 no.1
• /
• pp.33-36
• /
• 1975

To determine the dental arch length and width in Korean yaung adults, various points (shown on Fig 1) were measured by means of Boley gauge on the 124 plaster models which obtained from 2 young men. The measurements value were as follows: A : 36.10㎜ a : 25.53㎜ B : 33.35㎜ b : 28.20㎜ C : 39.80㎜ c : 33.07㎜ D : 43.36㎜ d : 36.36㎜ E : 44.80㎜ e : 39.12㎜ F : 49.11㎜ f : 42.48㎜ G : 59.98㎜ g : 44.92㎜ H : 62.22㎜ h : 57.85㎜ I : 52.66㎜ i : 49.91㎜

• The Journal of the Korean dental association
• /
• v.21 no.7 s.170
• /
• pp.525-528
• /
• 1983

치수가 어떤 병적상태에 있는지 정확히 구분해 내는 것은 매우 어려운 일이다. 한 병적상태에서 다른 질환으로 쉽게 이행되고 염증상태에 있는 치수는 위촉되어 질환을 분류하는데 중첩되고 또한 병리조직학적 관점에서 진단해 내야 하기 때문에 임상에서 정확한 진단을 내리는데는 난점이 많다. 그러나 환자가 호소하는 주증상과 기왕증은 진단에 매우 중용한 부분을 찾이 하고 술자가 관찰하는 여러 가지 시험들을 토대로 하여 종합관찰한 후에 진단을 내려야 할 것이다.

• Journal of the military operations research society of Korea
• /
• v.17 no.2
• /
• pp.90-99
• /
• 1991

In this paper a dispatching rule, $D^{*}$, for AGV operations in automated manufacturing system is proposed to improve the performance measures. And the algorithm is compared with existing heuristic rules via simulation to evaluate its capabilities. It is shown that the proposed rule enhances mean flow time, makespan and throughput, and avoids the locking phenominon which can be fatal to the operation of automated manufacturing systems.