MIM 공법 적용 커넥터 금형 가공용 방전 전극 개발

신광호,전용준,허영무,Shin, Kwang-Ho,Jeon, Yong-Jun,Heo, Young-Moo 한국금형공학회 2014 한국금형공학회지 Vol.8 No.2

A discharge electrode plays a role of shaving off workpiece with spark generated by current in discharge machining. Accordingly, for the discharge electrode, an electrode with excellent wear resistance is necessary. Generally, Graphite and Cu are used as the materials of the electrode, and recently Cu-W is mainly used as an electrode with excellent wear resistance. However, the form of the electrode generally used is produced mostly using cutting work, so a lot of costs incur if several similar forms are needed. Thus, this study developed a Cu-W electrode using Metal Injection Molding (MIM) process to produce similar forms with excellent productivity and a great quantity of electrodes in a similar form in discharge machining and carried out a discharge machining test. In developing an electrode applying MIM, predicting contraction of a product in a sintering process, a mold expansion ratio of 1.29486 was given, but the actual product showed a percentage of contraction 24% to 32%, which showed a difference of 3% to 5%. In addition, to verify wear resistance of the discharge electrode, abrasion loss was measured after the discharge.

CT Scanner를 이용한 아스팔트 혼합물의 공극특성 평가

신광호,김성겸,이관호,Shin,Kwang-Ho,Kim,Seong-Kyum,Lee,Kwan-Ho 한국방재학회 2012 한국방재학회논문집 Vol.12 No.3

아스팔트 혼합물의 공극은 아스팔트 혼합물의 소성변형과 같은 공용성능에 큰 영향을 준다. 최근 다양한 기능성을 고려한 배수성 아스팔트, 저소음 아스팔트, 보습성 아스팔트, SMA 등 다양한 아스팔트 혼합물이 개발되어 이용되고 있다. 이러한 다양한 기능은 주로 아스팔트 혼합물의 공극특성과 밀접한 상관관계를 가진다. 이에 본 연구에서는 아스팔트 혼합물의 공극특성을 평가하기 위하여 Micro CT Scanner를 이용하였다. 배수성아스팔트 혼합물, SMA 10 mm 혼합물 및 일반밀입도 아스팔트를 이용하여 공극특성을 분석하였다. PA-13 배수성포장용 아스팔트 혼합물과 SMA 10 mm 혼합물의 경우 다짐횟수가 작을수록 투수특성에 영향을 주는 유효공극량, 총공극량 및 공극의 연결율이 크게 나타났다. 다짐횟수 50타 및 75타로 다짐 시편간의 유효공극량, 총공극량 및 공극의 연결율의 차이는 비교적 작게 나타났다. 밀입도 아스팔트 혼합물의 경우 아팔트 시편내부에 개별적인 공극이 존재하지만, 이러한 공극이 연결되어 투수에 영향을 주는 공극은 거의 없는 것으로 분석되었다. CT Scanner는 아스팔트 혼합물의 공극 특성을 수치적으로 검증할 수 있는 실험방법으로 활용할 수 있을 것으로 판단된다. The void of asphalt pavement effects very much on the performance of asphalt pavement, including permanent deformation. In recent, lots of multi-functional hot mix asphalt have been developed. The multi-functional properties depend on the void characteristic of hot mix asphalt. In this research, the Micro CT scanner is adopted to verify the void characteristic of hot mix asphalt. Couple of different mixtures, including permeable asphalt pavement, SMA and dense-graded asphalt mixture, were used for void analysis. In case of PA-13 permeable asphalt pavement and SMA 10mm, the effective void, total void and the ratio of connection between void increase as the level of compaction decreases. There is a little difference of the effective void, total void and the ratio of connection for 50 blows/side and 75 blows/side of compaction. In case of dense-graded asphalt mixture, there is a small amount of void, but most of void is isolated, which means little effect on the permeability of asphalt mixtures. Judging from the limited test results, a Micro CT scanner will be an alternative to analyze the void properties of asphalt mixtures. The correlation of unconfined compressive test and impact resonant test was relatively good.

Denta $Scan^R$을 이용한 즉시 임플랜트 시술시 최적의 식립 위치 대한 통계적 연구

신광호,이재봉,황병남,Shin, Kwang-Ho,Lee, Jai-Bong,Hwang, Byung-Nam 대한치과보철학회 2000 대한치과보철학회지 Vol.38 No.4

Purpose : The purpose of this study was to determine proper position and angulation of an implant for immediate implantation. Materials and Method : From the years 1997 to 2000. 52 Denta $scan^R$ views, 22 upper and 32 lower jaw with an average age of 43 and 40 respectively, were investigated, which comprise intact upper and lower 6 anterior teeth and premolars. On the Denta $scan^R$, the optimal placement for the immediated implantation was simulated. The measuring methods included 1) Angulation difference between tooth long axis and alveolar bone process. 2) Angulation difference of long axis between tooth and installing fixture 3) Distance between center of tooth at cervical area and center of fixture. 4) Distance from root apex to the bone limit of vital structure. One sample t-test was used for statistical analysis. Result : The results were as follows. 1) At the maxillary central incisor and lateral incisor, angulation difference of long axis between tooth and installing fixture was respectively 0.5 and 3.2 degrees with the fixture center's palatally positioned 2mm apart from tooth center. 2) At the lower anterior 6 teeth, that was about $-2.8^{\circ}\;to\;-4.6^{\circ}$ with the fixture center's lingually positioned 1mm apart from tooth center. 3) At the maxillary canine and premolar, that was respectively $11.8^{\circ}\;and \;7.2^{\circ}$ with the fixture center palatally positioned $2\sim2.4mm$ apart from tooth center. 4) At the lower premolar area, that was about $0^{\circ}\;to\;2^{\circ}$ with the fixture center's lingually positioned $0.5{\sim}1mm$ apart from tooth center. 5) Distance from root apex to the bone limit of vital structure, at the maxillary anterior and premolars. was the range of 10 to 12mm, and at the mandibular anterior teeth and the 1st premolar, that was the range of 18 to 20mm. Conclusion : The proper implant position of maxillary anterior and premolar teeth is as paralleled as or more buccally angulated than long axis of tooth with the fixture center's palatally positioned. In mandiblular anterior region, long axis of implants is lingully angulated compared with long axis of tooth and in premolar, almost parelleled with long axis of tooth and alveolar process.

Dexamethasone과 Naproxen 병용투여가 하악 제3대구치 발거 후 증상에 미치는 영향에 관한 임상적 연구

신광호,이정근,황병남,Shin, Kwang-Ho,Lee, Jeong-Keun,Hwang, Byung-Nam 대한구강악안면외과학회 2001 대한구강악안면외과학회지 Vol.27 No.1

PURPOSE : The Purpose of this study was to investigate the anti-inflammatory effect on combination dosage of dexamethasone and naproxen after removal of impacted 3rd molars. We evaluated postoperative pain, swelling, and mouth opening limitation quantitatively. PATIENTS AND METHODS : Removal of an impacted lower third molar was done under local anesthesia with 2% lidocaine to 239 healthy patients. We randomly gave experimental group 1.5mg dexamethasone and 200mg naproxen three times a day for postoperative 2days, and also gave control group 200mg naproxen alone three times a day for postoperative 2days. Swelling and pain were measured by visual analogue scale (VAS). Mouth opening limitation was measured by maximum interincisal opening length. We estimated these measurements in the first and second postoperative days. Differences between experimental and control group were investigated considering age, sex, BMI(body mass index), impacted type, surgical site(right or left), and operation time by independent student T-test. RESULTS : In general, swelling, pain, and mouth opening limitations were significantly reduced (p<0.01) by combination dose of dexamethasone and naproxen in postoperative one day. But there was no difference in pain on the second postoperative day. As variables being considered, in the postoperative pain, there was significant difference between experimental group and control group in only male, little bony removal group, left side extraction group. In case of postoperative swelling, there was no significant differences in male, adolescence, long operating time group (over 20 minutes), medium BMI group and right side extraction group. In case of postoperative mouth opening limitation, there was significant difference between only female and long operating time group (over 20 minutes). CONCLUSION : Variables being considered, postoperative swelling was more reduced by the combination dose of naproxen and dexamethasone than that of naproxen alone after removal of impacted 3rd molars. But there was varoius results in pain and mouth opening limitation.

모형챔버시험을 이용한 사질토 지반의 경량포장체용 기초의 하중전달 특성

신광호(Shin, Kwang-Ho),황철비(Hwang, Cheol-Bi),전상렬(Jeon, Sang-Ryeol),이관호(Lee, Kwan-Ho) 한국산학기술학회 2014 한국산학기술학회논문지 Vol.15 No.7

본 연구에서는 연약지반에서의 경량콘크리트포장을 적용할 때의 안전성 평가를 위해 실제 포장체 사이즈의 1/30으로 축소한 모형을 이용하여 모래지반에서 실험을 실시하였다. 모형토조를 이용하여 지반을 조성하였고, 표준 말뚝재하시험(완 속재하시험방법)을 이용하였다. 수직하중이 적용되는 말뚝기초의 슬래브의 중심에서 가까운 순으로 Case A, Case B, Case C로 구분하였고, 각각의 말뚝의 간격은 8cm로 하였다. 말뚝기초 모형시험결과 사질토지반에서 수직하중을 1.5kg에서 12kg로 증가시킬 때 포장체가 전체적으로 침하하였고, 최대 침하량은 0.4mm로 측정되었다. Case A의 경우 압축력을 받는 것으로 나타났으며, Case B는 수직하중이 증가함에 따라 말뚝에 압축력과 함께 인장력도 같이 받는 것으로 보이며, Case C는 하중단 계가 증가할수록 인장변형이 증가하는 경향을 나타내었다. In this study, small scaled (1/30) laboratory chamber tests of the pile foundation for a lightweight concrete pavement system were carried out to evaluate the safety of a pile foundation on sandy soil. The testing ground was simulated in the field and a standard pile-loading test was conducted. The test piles were divided into 3 types, Cases A, B and C, which is the location from the center of the slab by applying a vertical load. The interval between the piles was set to 8 cm. As a result of the pile foundation model test, the pavement settled when the vertical load was increased to 12kg from 1.5kg in sandy soil ground, particularly the maximum settlement of 0.04mm. Judging from the model chamber test, Case A showed compressive deformation, whereas Case B represented the compression and tensile forces with increasing vertical load. Case C showed an increase in tensile strain.

LC공진소자를 이용한 변위센서

신광호(Kwang-Ho Shin) 한국자기학회 2015 韓國磁氣學會誌 Vol.25 No.1

In this study, the LC resonators were fabricated with ferrite cores and external capacitors, and then their characteristics were investigated for the purpose of developing new displacement sensor. The frequency dependence of impedance of single resonator was estimated. There were two resonance peaks on the impedance spectrum; one by self inductance and the other by mutual inductance. The resonance frequency was shifted linearly in direct proportion to displacement of the resonator showing the proposed device, a pair of LC resonators, could be used a precision displacement sensor.

안전관제시스템 프로토콜 표준화를 위한 데이터 수집 방법

신광호(Kwang-Ho Shin),엄태화(Tae-Hwa Um),임담섭(Dam-Sub Lim),안진(Jin Ahn) 한국철도학회 2016 한국철도학회논문집 Vol.19 No.2

Cu-Zn 페라이트/고무 복합형 전파흡수체에 있어서 PZT첨가가 전파흡수특성에 미치는 영향

申光鎬(Kwang-Ho Shin),司空鍵(Geon Sa-Gong) 대한전기학회 1995 전기학회논문지 Vol.44 No.5

압전 유니몰프 진동자를 이용한 진동형 시료 자력계

신광호(Kwang-Ho Shin) 한국자기학회 2019 韓國磁氣學會誌 Vol.29 No.4

A vibrating sample magnetometer with a unimorph piezoelectric actuator as vibrating mechanism is proposed in this paper. By adopting a piezoelectric vibrating mechanism, we could achieve both high sensitivity and small-sizing of VSM. To enhance the sensitivity, the optimal vibrating frequency was investigated by a set of FEM structural analysis. When an alternating voltage was applied to the unimorph piezoelectric actuator, the acryl cantilever is vibrated transversely. At the end of the cantilever, on which a magnetic specimen was attached, the maximum vibration amplitude was ~1.6 mm at 160 Hz. The proposed VSM showed high resolution ~2 × 10<SUP>−5</SUP> emu due to an extremely large vibrating amplitude, even if it has an extremely small size (30 × 25 × 25 cm³) compare with conventional VSMs.

페라이트 코어와 칩캐패시터의 주기적 연결구조에서 발생하는 자기유도파

신광호(Kwang-Ho Shin) 한국자기학회 2015 韓國磁氣學會誌 Vol.25 No.1

In this paper, a magneto-inductive wave generated in a chain of LC resonators fabricated with Ni-Zn ferrite cores and chip capacitors is presented. RF signal propagates to neighbor resonator one by one as a consequence of the magnetical coupling between two resonators in the device. The magnetical coupling is due to the mutual inductances along the chain of resonators. So, the signal amplitude (? coupling intensity) is dependent of the mutual inductance which can be adjusted by applied magnetic field. In order to demonstrate the device, some experiments have been carried out systemically. The transmission characteristics of a magneto-inductive wave could be controlled by applied external magnetic field. The device composed of 5 resonators; the center frequencies were estimated to be 32 MHz and 38 MHz with the external magnetic flux density of 75 Oe and 222 Oe, respectively. We expect that the reported results could open a promising way to a high variety of applications in one- and two-dimensional functional devices, such as transducers, delay lines, power dividers and couplers.