• Journal of radiological science and technology
• /
• v.35 no.2
• /
• pp.151-156
• /
• 2012

$^{18}F$-fluorodeoxyglucose ($^{18}F$-FDG) causes a significant amount of radioactivity retention in kidneys and urinary tract and degrades image quality and diagnostic performance. Diuretics are used to perform tests and prevent the urinary tract retention of $^{18}F$-FDG. The purpose of the study is to investigate how the diuretics affect images and excretion rates of $^{18}F$-FDG. The study consists of a group using diuretics for patients with no primary tumors or transfer lesions in kidneys according to PET/CT images, a group using physiological saline and the control group injecting only $^{18}F$-FDG and SUVs are measured by configuring interested areas for each group. Also, SUVs are compared and evaluated depending on the lasix injection after basic inspection and injecting $^{18}F$-FDG for quantitative analysis. The study shows that images with decreased background radioactivity and increased urine excretion due to using diuretics. However, an opposite result that there is no change in the amount of radioactivity in urine appears. The study concludes that the diuretics may decrease background radioactivity in the images but may not affect the $^{18}F$-FDG excretion.

• Korean Journal of Head & Neck Oncology
• /
• v.19 no.1
• /
• pp.58-62
• /
• 2003

Purpose: To evaluate the efficacy of positron emission tomography with 2-[F-18] fluoro-2-deoxy-D-glucose in discrimination of response in the nasopharyngeal carcinoma patients who treated with radiotherapy. Methods and Materials: Twenty-four patients who underwent FDG-PET scan before and after radiotherapy for no disseminated head and neck carcinoma at the Asan Medical Center between August 2001 and September 2002 were evaluate by prospective analysis. First FDG-PET scan performed before radiotherapy within 1 month, and second FDG-PET scan performed 1 month after radiotherapy. FDG-PET images were analyzed by standard uptake value (SUV). Follow-up period was more than 6 months. Results: The pretreatment SUV was 3.4-14.0 (median: 6.0) and posttreatment SUV was ground level-7.7 (median: 2.0). The overall sensitivity and specicity of FDG-PET to evaluate residual tumors in the nasopharyngeal carcinoma patients were 94% and 94%. Conclusion: FDG-PET is effective in evaluation of radiation response in the nasopharyngeal carcinoma. We think that the timing of one month after finished radiotherapy FDG-PET scan was not too fast to evaluation of radiation response.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.27 no.2
• /
• pp.111-127
• /
• 2023

Purpose: Gallium-68 (⁶⁸Ga) is increasingly used in nuclear medicine imaging for various conditions such as lymphoma and neuroendocrine tumors by labeling tracers like Prostate Specific Membrane Antigen (PSMA) and DOTA-TOC. However, compared to Fluorine-18 (¹⁸F) used in conventional nuclear medicine imaging, ⁶⁸Ga has lower spatial resolution and relatively higher Signal to Background Ratio (SBR). Therefore, this study aimed to investigate the optimized parameters and reconstruction methods for PET/CT imaging using the ⁶⁸Ga radiotracer through model-based image evaluation. Materials and Methods: Based on clinical images of ⁶⁸Ga-PSMA PET/CT, a NEMA/IEC 2008 PET phantom model was prepared with a Hot vs Background (H/B) ratio of 10:1. Images were acquired for 9 minutes in list mode using DMIDR (GE, Milwaukee WI, USA). Subsequently, reconstructions were performed for 1 to 8 minutes using OS-EM (Ordered Subset Expectation Maximization) + TOF (Time of Flight) + Sharp IR (VPFX-S), and BSREM (Block Sequential Regularized Expectation Maximization) + TOF + Sharp IR (QCFX-S-400), followed by comparative evaluation. Based on the previous experimental results, images were reconstructed for BSREM + TOF + Sharp IR / 2 minutes (QCFX-S-2min) with varying β-strength values from 100 to 700. The image quality was evaluated using AMIDE (freeware, Ver.1.0.1) and Advanced Workstation (GE, USA). Results: Images reconstructed with QCFX-S-400 showed relatively higher values for SNR (Signal to Noise Ratio), CNR (Contrast to Noise Ratio), count, RC (Recovery Coefficient), and SUV (Standardized Uptake Value) compared to VPFX-S. SNR, CNR, and SUV exhibited the highest values at 2 minutes/bed acquisition time. RC showed the highest values for a 10 mm sphere at 2 minutes/bed acquisition time. For small spheres of 10 mm and 13 mm, an inverse relationship between β-strength increase and count was observed. SNR and CNR peaked at β-strength 400 and then decreased, while SUV and RC exhibited a normal distribution based on sphere size for β-strength values of 400 and above. Conclusion: Based on the experiments, PET/CT imaging using the ⁶⁸Ga radiotracer yielded the most favorable quantitative and qualitative results with a 2 minutes/bed acquisition time and BSREM reconstruction, particularly when applying β-strength 400. The application of BSREM can enhance accurate quantification and image quality in ⁶⁸Ga PET/CT imaging, and an optimization process tailored to each institution's imaging objectives appears necessary.

• 한국방재학회:학술대회논문집
• /
• 2007.02a
• /
• pp.462-467
• /
• 2007

Recently, in Korea vehicle market, the proportion of SUV is increasing. However Korea SINCAP(Side Impact New Car Assessment Program) doesn't reflect this circumstance. This paper focused on improvement of Korea SINCAP by comparing IIHS(Insurance Institute of Highway Safety) side impact test protocol with Korea SINCAP.

• 한국IT서비스학회:학술대회논문집
• /
• 2009.05a
• /
• pp.154-157
• /
• 2009

본 연구는 SCM의 전략적인 성공적인 운영을 위하여 선행연구를 통해 SCM의 성공요인을 도출하였다. 연구의 목적을 달성하기 위하여 국내 상장기업 중 공급망 관리를 추진하고 있는 기업을 대상으로 설문조사를 실시하였고, 수집된 데이터로 실증 분석을 하였다. 실증 분석 결과 SCM의 주요 성공요인은 "CEO의 리더십 SCM 의지", "SC간 정보공유", "상황변화에 신속공동 대응", "SCM 전담팀의 구성", "SC간 협업", "파트너 간 상호신뢰" 요인으로 함축 되었으며 SCM에 대한 주요 성공요인이 변화 관리적인 측면에서 지속적으로 추진되어야 함을 시사하고 있다.

• Asia Marketing Journal
• /
• v.4 no.3
• /
• pp.75-85
• /
• 2002

경쟁이 치열한 글로벌 시장에서 우리나라 기업이 국제적인 경쟁우위 확보가 필수적인 세계 경제환경이다. 고객의 요구를 선행적으로 파악하고 상품개발과 디자인에서 고객만족을 달성한 현대 자동차의 싼타페 사례를 분석한다. 퓨전 SUV 싼타페의 성공요인은 크게 두 가지로 볼 수 있다. 첫째, 소비자의 요구를 선행적으로 반영하여 안전성과 품질 면에서 뛰어난 성능을 가진 제품을 개발한 것이다. 둘째, 미국 현지주도의 디자인 개발로 세단을 능가할 수 있는 세련된 디자인과 알맞은 차체 사이즈로 글로벌 시장에서 소비자의 요구를 충족시킨 것이다. 아울러 향후 제품 포지셔닝에 관한 전략적 방향을 분석한다.

• Journal of Gastric Cancer
• /
• v.11 no.3
• /
• pp.173-179
• /
• 2011

Purpose: It is difficult to obtain biopsies from gastrointestinal stromal tumors (GISTs) prior to surgery because GISTs are submucoal tumors, despite being the most common nonepithelial neoplasms of the gastrointestinal tract. Unlike anatomic imaging techniques, PET-CT, which is a molecular imaging tool, can be a useful technique for assessing tumor activity and predicting the malignant potential of certain tumors. Thus, we aimed to evaluate the usefulness of PET-CT as a pre-operative prognostic factor for GISTs by analyzing the correlation between the existing post-operative prognostic factors and the maximum SUV uptake (SUVmax) of pre-operative 18F-fluoro-2-deoxyglucose (FDG) PET-CT. Materials and Methods: The study was conducted on 26 patients who were diagnosed with gastric GISTs and underwent surgery after being examined with pre-operative FDG PET-CT. An analysis of the correlation bewteen (i) NIH risk classification and the Ki-67 proliferation index, which are post-operative prognostic factors, and (ii) the SUVmax of PET-CT, which is a pre-operative prognostic factor, was performed. Results: There were significant correlations between (i) SUVmax and (ii) Ki-67 index, tumor size, mitotic count, and NIH risk group (r=0.854, 0.888, 0.791, and 0.756, respectively). The optimal cut-off value for SUVmax was 3.94 between "low-risk malignancy" and "high-risk malignancy" groups. The sensitivity and specificity of SUVmax for predicting the risk of malignancy were 85.7% and 94.7%, respectively. Conclusions: The SUVmax of PET-CT is associated with Ki-67 index, tumor size, mitotic count, and NIH classification. Therefore, it is believed that PET-CT is a relatively safe, non-invasive diagnostic tool for assessing malignant potential pre-operatively.

• The Journal of the Korea Contents Association
• /
• v.15 no.7
• /
• pp.106-116
• /
• 2015

Recently, growing up in social and economic development, the lifestyle of Koreans brought many changes in the form of leisure activity and influenced a lot in leisure. In particular, the establishment of the five-day work week increased the leisure time and became popular with family activities. Accordingly, the base of the leisure population expanding, people have an interest in the new way of leisure and the desire is increasing. Camping culture that increasingly take place in the tent camping now is changing into a cultural center to enjoy the camping SUV vehicle. The desire of consumers for the design of the unique exterior and interior caravan increasingly appearing as a major requirement. In this study, we propose a caravan design development strategies to meet the needs of such customers. First analyzes the hypothesis set and to identify the Overview of the caravan, and optimization of use and the problem of the user. Proceed with the design map analysis through classification of the caravan design registered in the KIPO, and proceed to the market research and patented technology to identify and to proceed with the caravan design development strategies for the various products.

• Journal of Hydrogen and New Energy
• /
• v.28 no.2
• /
• pp.220-224
• /
• 2017

Nitrogen dioxide ($NO_2$) is an important urban pollutant in Korea. Expecially, diesel vehicles are responsible for the most traffic rated nitrogen oxide ($NO_X$) emission, including nitric oxide (NO) and nitrogen dioxide ($NO_2$). Though nitrogen oxide ($NO_X$) emission from vehicle was applied a strict enforcement of emission standard, the specific $NO_2$ fraction in $NO_X$ ($NO_2/NO_X$) from various types of diesel vehicles was not understood. In order to investigate the fraction of $NO_2/NO_X$, the vehicle emission study was carried out at the facility of Transport Pollution Research Center (TPRC), National Institute of Environmental Research (NIER), Korea. Three different types of diesel vehicles(VAN, SUV, passenger) were tested on the NIER driving mode. The result of $NO_2/NO_X$ ratio was over 0.1 for all test vehicles and the highest $NO_2$ emission was observed at the van vehicle. The observation was showed that the emission trend of $NO_2/NO_X$ for passenger and SUV vehicles were inversely proportional. Also, as the emission standard has been strengthen, the emission rate of $NO_2$ has been decrease.

• Proceedings of the Korea Society of Design Studies Conference
• /
• 2004.10a
• /
• pp.234-235
• /
• 2004

현재 자동차의 변화를 이끄는 흐름에서 가장 핵심이 되고 있는 유형 Sport Utility Vehicle은 전천후 기동성 측면과 Sports성을 중심적인 특성으로 다루고 있다. 그러나 SUV로서 off road 중심의 공간 활용 보다는 실내 공간 중심의 활용이 더욱 중요한 특성으로 자리잡고 있다. 이러한 경향은 주 5일 근무 정착에 따른 여가 시간의 증가와 아울러 보다 다양한 직업과 생활 패턴 등에 따라 더욱 두드러질 것으로 보인다. 이러한 근 미래 변화에 대응하는 방법으로 기존의 SUV type에서 탈피하여 sports성을 반영하는 동시에 보다 utility적 활용 중심의 특성을 가지는 XUV (eXtreme Utility Vehicle)라는 새로운 유형을 2010년 시점의 근 미래 테크놀러지와 조형성의 동향 예측, 사용자 요구점 분석 포지셔닝 등을 통해 제안한다.