• Journal of the Korean Society of Radiology
• /
• v.1 no.3
• /
• pp.5-10
• /
• 2007

This study was performed to measure about exposure dose during simple abdmon radiation radiography. The exposure dose was measured by PDD, surface dose, respectively. The result was as followed: 1. When tube voltage were increased with 60-85kv, surface dose were increased. When FFD(focus film distance) at the 50-150cm and mAs were increased, surface dose were decreased. 2. The percentage depth dose(PDD) were appeared 50% below depth dose at 4cm with 60-75kv, and 6cm depth with 80-85kv, 5% below depth dose at 12cm with 60kv, and depth with 65-85kv. 3. The percentage forward scatter increased from 10% to 11.78% at the 60-85kv. The back scatter dose were increase from 25% to 37% at the 60-85kv. The side scatter dose were affected to heel effect.

• Elastomers and Composites
• /
• v.40 no.1
• /
• pp.45-52
• /
• 2005

Synthesis or fullerene oxides[$C_{60}(O)_n$] ($n=1{\sim}4$ or n=1) by fullerene[$C_{60}$] and several oxidants such as 3-chloroperoxy benzoic acid, benzoyl peroxide, trichloroisocyanuric acid, and chromium(VI) oxide took place under microwave irradiation. The reactivity in solid state of fullerene[$C_{60}$] with various oxidants under same microwave rendition increased in order or 3- chloroperoxy benzoic acid > benzoyl peroxide > trichloroisocyanuric acid $\simeq$chromium(VI) oxide. The MALDI-TOF-MS, UV-visible spectra and HPLC analysis confirmed that the products of fullerene oxidation were [$C_{60}(O)_n$] ($n=1{\sim}4$ or n=1).

• The Transactions of the Korean Institute of Power Electronics
• /
• v.10 no.5
• /
• pp.450-456
• /
• 2005

In this paper new 60-step inverter system for medium-to-large scale STATCOM is proposed and operating principle along with control method is detailed. A simple auxiliary circuit is employed to Improve output voltage waveform of 12-step into 60-step. The proposed scheme could be a cost effective approach in high power application such as 10Mvar to 30Mvar STATCOM. Experimental results from a 2KVA laboratory prototype show validity of the proposed method.

• Electronics and Telecommunications Trends
• /
• v.27 no.1
• /
• pp.93-100
• /
• 2012

디지털 영상 미디어 기술의 발전과 초고속 무선 전송에 대한 요구가 증가함에 따라 수 Gbps급 무선 전송을 현실화한 연구 결과가 국내외에서 많이 발표되고 있다. 이 가운데 가장 주목을 받고 있는 기술이 바로 60GHz 대역 통신이다. 이는 60GHz 대역이 ISM 대역임에도 불구하고 최대 9GHz까지의 엄청난 대역폭을 활용할 수 있어서 Gbps급 무선 전송에 가장 적합하기 때문이다. 하지만 60GHz 전파는 대기 중 감쇄가 심하기 때문에 무선 네트워크 구성을 위해서는 고성능의 무선 송수신 단말을 필요로 한다. 따라서 단말에서 사용하게 될 안테나 및 송수신 칩은 60GHz 대역의 광대역 신호를 처리하고 고출력, 고이득이 구현되어야 할 뿐만 아니라, 크기, 소모 전력, 그리고 가격적인 측면을 고려해야 하는 고도의 설계 기술을 필요로 하고 있다. 본고에서는 60GHz 대역의 이용 현황, 표준화 동향과 함께 송수신 칩 기술동향에 대해 살펴보고자 한다.

• Elastomers and Composites
• /
• v.41 no.1
• /
• pp.57-62
• /
• 2006

The reaction of fullerene$[C_{60}]$ and 3-chloroperoxy benzoic acid in 1,2-dichlorobenzene was monitored by high resolution ultrasonic spectroscopy and the product of reaction by fullerene $[C_{60}]$ and 3-chloroperoxy benzoic acid in 1,2-dichlorobenzene was characterized using MALDI-TOF-MS spectra.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.16 no.1
• /
• pp.34-37
• /
• 2012

Purpose: To verify the optimal scan time per bed for clinical application, we evaluated the quality of $^{18}F$-FDG images with varying scan times in a phantom and 20 patients with 38 lesions using a Philips (TOF) PET/CT scanner. Materials and Methods: The PET/CT images of a NEMA IEC body phantom and 20 patients (16 males, 4 females) were acquired for 5 different scan times of 20-100 sec per bed with intervals of 20 sec. The activity ratio of hot spheres (diameter of 17 [H1], 22 [H2] and 28 [H3] mm) to the background region in the IEC body phantom was 8-to-1. The contrast recovery coefficient (CRC) and standard uptake value (SUV) based on ROIs of hot spheres and background region were calculated. The noise in each background region was estimated as the ratio of SD of counts to the mean counts in the background region. On the patient image, the injected dose of $^{18}F$-FDG was $444{\pm}74$ MBq and the SUVs in the 38 hot lesions were measured. Results: The two scan time groups (LT-60 [<60 sec] and GT-60 [${\geq}60$ sec]) were compared. In the phantom study, the coefficient of deviations (CVs, %) of CRC and SUV in LT-60 (H1: 14.2 and 7.3, H2: 11.4 and 7.8, H3: 4.9 and 3.2) were higher than GT-60 (H1: 8.9 and 2.8, H1: 8.2 and 5.0, H3: 2.0 and 1.6). In the patient study, the mean CV of CRC and SUV in LT-60 (4.0) was higher than GT-60 (1.2). Conclusion: This study showed that noise increased as the scan time decreased. High noise for the scan time <60 sec per bed yielded high variation of SUV and CRC. Therefore, considering PET/CT image quality, the scan time per bed in the TOF PET/CT scanner should be at least ${\geq}60$ sec.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.4
• /
• pp.336-341
• /
• 2002

This experiment was conducted to evaluate the lysine cell mass (LCM) as a dietary fish meal (EM) protein replacer in juvenile Israeli carp, Cyprinus carpio. Fishmeal, a major animal protein source in the control diet, was replaced by tCM on the protein equivalent base, Fish averaging 1,7 $\pm$ 0.1 g (Mean $\pm$ SD) fed one of nine diets containing isonitrogenous and isocaloric basis of $38\%$ crude protein and 15.2 kJ available energy/g diet: control, $100\%$ $FM; LCM_20$, $80\%$ $FM+20\%$ $LCM; LCM_40$, $60\%$ $FM+40\%$ $LCM; LCM_60$, $40\%$ $FM+60\%$ $LCM; LCM_100$, $100\%$ $LCM; LCM_20$l, $80\%$ $FM+20\%$ $LCM+0.07\%$ $Lysine; LCM_40$l, $60\%$ $FM+40\%$ $LCM+0.14\%$ $Lysine; LCM_60$l $40\%$ $FM+60\%$ $LCM+0.22\%$ Lysine; LCM_100l, $100\%$ LCM+$0.35\% Lysine. After 6 weeks of feeding trial there was no significant difference in weight gain (WG), feed efficiency (FE), protein efficiency ratio (PER) and specific growth rate (SGR) among fish fed control and $LCM_20$ (P>0.05), while fish fed $LCM_40,\;LCM_60,\;LCM_100,\;LCM_40l,\;LCM_60l\;and\;LCM_100l$ diets had a significantly lower WG, FE, PER and SGR than did fish fed control diet (P<0.05). There was no significant difference in WG, PER and SGR among fish fed control and $LCM_20$l diets (P>0.05), while fish fed $LCM_20$l S had a significantly lower FE than did fish fed control diet (P<0.05). No significant difference was observed in hematocrit and condition facto, among fish fed nine diets (P>0.05). Therefore, these results indicated that LCM could replace FM up to $20\%$ and dietary synthetic lysine supplementation did not show any positive growth effects in juvenile Israeli carp.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.8
• /
• pp.2703-2706
• /
• 2012

New C60 fullerenes derivatives [G1]-C60 (1) and [G2]-C60 (2) comprising of phenylenevinylene bridges and phenylquinoline peripheral surface groups were synthesized by 1,3-dipolar cycloaddition reaction of fullerene C60 with azomethine ylide in situ generated from [Gx]-CHO dendrons (x = 1 and 2) and sarcosine.

• Proceedings of the Korea Water Resources Association Conference
• /
• 1992.07a
• /
• pp.506-512
• /
• 1992

PET병에 넣어 시판되고 있는 일부 물중에서 일반세균과 대장균이 문제되고 있어 이러한 균을 멸균하기 위한 실험을 Cobalt-60과 X-ray를 이용하여 효과를 비교했다. 그 결과 Cobalt-60에 의해서 1.1KGY의 선량으로 물속의 모든 균은 멸균되었으나 X-ray에 의한 실험(56KVP 1mA 9초까지의 조사)에는 효과가 없었다. 앞으로 장기간 보관식품은 Cobalt-60에 의한 조사가 효과적이라고 생각되며 아울러 조사된 물은 인체에 하등의 영향을 주지 않는다.

• Proceedings of the Korea Contents Association Conference
• /
• 2011.05a
• /
• pp.335-336
• /
• 2011

하이브리드 자동차 기술 분야에서 한국의 현대자동차가 575건으로 가장 많은 등록특허를 보유한 것으로 나타났으며, 일본의 TOYOTA MOTOR가 565건의 특허를 보유하고 있는 것으로 나타났다. 주요 출원인별 IPC 분포를 통해 연구개발 역점분야를 살펴보면, 주요 상위 출원인은 하이브리드 관련 배치(B60K), 하이브리드 관련 제어(B60W), 전기장치(B60L)에 집중하여 연구개발이 진행되었다. TOYOTA MOTOR와 NISSAN MOTOR는 하이브리드 관련 제어(B60W), HONDA MOTOR는 하이브리드 관련 배치(B60K) 및 전동기(H02P)관련 연구에 역점을 두고 있었다.