• The Korean Journal of Nuclear Medicine
• /
• v.37 no.6
• /
• pp.393-401
• /
• 2003

Objective: Pullulan derivatives (PD) can be used to make self-assembled hydrogel nanoparticles which are responsive to ionic strength. The aim of this study is to evaluate the potential of PD as a retaining carrier of radioisotope inside tumors. Materials and Methods: Four types of PD were evaluated which included pullulan acetate (PA), succinylated PA (SPA), PA-DTPA and SPA-DTPA conjugates. They were radiolabeled with Tc-99m. Labelling efficiencies were determined at 30 min, 1, 2, 4 and 12 hours after radiolabeling. CT-25 colon cancer cells were subcutaneously injected into Balb/c mice. After 2 weeks of subcutaneous injection, Tc-99m-labelled PD (Tc-99m-PD) were injected into the tumors. Whole body images of mice were obtained at 30 min, 1, 2, and 12 hr after intratumoral injection. All twenty mice were grouped into four groups by largest diameter; control A (largest diameter = 5 mm, n = 5), control B (largest diameter = 10 mm, n = 5), pullulan A (largest diameter = 5 mm, n = 5), pllulan B (largest diameter = 10 mm, n = 5). Dynamic images were obtained for 1 hour after intratumoral injection. Static images were obtained at 1 hr, 2 hr, 3 hr and 4 hr after intratumoral injection with Tc-99m pertechnetate and Tc-99m-PA. Target-to-background ratios and retention rates were calculated. Results: Labeling efficiencies of PA, SPA, PA-DTPA and SPA-DTPA were $94.5{\pm}5.9%,\;97.8{\pm}3.5%\;94.2{\pm}3.8%,\;and\;92.5{\pm}6.2%$, respectively (p>0.05). Percent retention rates (%RR) of PA and PA-DTPA were significantly higher than those of control, however, those of SP-DTPA and SPA became similar to control at 4 and 12 hr, respectively. %RR of pullulan A and pullulan B at 1, 4 and 8 hr is significantly higher than that of control (p < 0.05). However, %RR between pullulan A and pullulan B were similar. Conclusion: The lonic strength dependent PD-nanoparticles are retained in the tumor. No difference of %RR according to tumor size was noted. Therapeutic application of PD labelled with beta- or alpha- emitting radionuclides can be expected.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.12 no.1
• /
• pp.39-43
• /
• 2008

Purpose: There are various methods to diagnose hemangioma, such as ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine. However, by development of SPECT imaging, the blood-pool scan using $^{99m}Tc$-labeled red blood cell has been used, because it was non-invasive and the most economical method. Therefore, in this study, we proposed that the usefulness of $^{99m}Tc$-RBC scan and SPECT of the head and neck to diagnose unlocated hemangiomas. Materials and Methods: $^{99m}Tc$-RBC scan and SPECT was performed on 6 patients with doubtful hemangioma (4 person, head; 1 person, neck; 1 person, another). We labeled radiopharmaceutical using modified in vivo method and then, centrifuged it to remove plasma. After a bolus injection of tracer, dynamic perfusion flow images were acquired. Then, anterior, posterior, both lateral static blood-pool images were obtained as early and 4 hours delayed. SPECT was progressed 64 projections per 30 seconds. Each image was interpreted by physicians, Nuclear medicine specialist, and technologist blinded to patient's data. Results: In 5 patients of all the radioactivity of doubtful site didn't change in flow images, but, in blood-pool, delayed and SPECT images, it was increased. So, it was a typical hemangioma finding. The size of lesion was over 2 cm, and it could discriminate as comparing to the delayed and SPECT imaging. On the other hand, in 1 patient, the radioactivity was increased in blood-pool images, but, not in delayed and SPECT images, so, it was proved no hemangioma. Conclusion: Using $^{99m}Tc$-RBC Scan and SPECT, we could diagnose the hemangiomas in head and neck, as well as, liver, more non-invasive, economical, and easy. Therefore, it considered that $^{99m}Tc$-RBC scan and SPECT would offer more useful information for diagnosis of hemangioma, rather than otherimaging such as US, CT, MRI.

• Journal of Korean Ophthalmic Optics Society
• /
• v.19 no.2
• /
• pp.225-229
• /
• 2014

Purpose: The study was to analyze the correlation between kinetic visual acuity (KVA), visual acuity(static visual angle, SVA) and contrast sensitivity. Methods: Ninety-nine undergraduate students studying Ophthalmic Optics were fully corrected by the Topcon CV-3000 Phoropter. The contrast sensitivity was measured for the participants under the photopic condition ($100cd/m^2$) with Vector Vision CSV-1000E at 2.5 meter, while KVA was measured with KOWA AS-4A. The participants were classified into three groups L, M and H depending on the KVA (0.1~0.3, 0.31~0.6 and greater than 0.61, respectively) and were analyzed whether there was the correlation between the contrast sensitivity, visual acuity and refractive error. Results: The KVA was correlated with the contrast sensitivity for 3 cpd (r=0.26), for 6 cpd (r=0.48), for 12 cpd (r=0.38) and 18 cpd (r=0.47). Except for the low frequency of 3 cpd, they all were higher than the one of the SVA and the KVA (r = -0.37). The contrast sensitivity for 3, 6, 12 and 18 cpd was 59.41, 92.22, 38.41 and 14.39 in the group L, respectively. The contrast sensitivity in the group M was 66.03, 108.78, 53.51 and 19.20 and the one in the group H was 70.90, 146.10, 62.90 and 25.33 for 3, 6, 12 and 18 cpd, respectively. Conclusions: The correlation of the contrast sensitivity and the KVA was higher than the one of the contrast sensitivity and the SVA. It can be assumed that the contrast sensitivity will be high if the KVA is high, except for the case for low spatial frequency.

• Proceedings of the IEEK Conference
• /
• 2004.06a
• /
• pp.99-102
• /
• 2004

Caching is one of essential functions in a wireless internet proxy server cluster. To serve best quality of service and choose suitable a proxy server for user, load balancer have to consider cache cooperation between proxy servers. Usually hashing is a simple way to support cache cooperation. In this paper, we compare and analysis static hashing and MD 5 that can be used for cache cooperation.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.4 no.1
• /
• pp.99-110
• /
• 2002

This study is performed to investigate the effect of the mordant and chitosan on the colorfastness to laundering and physical properties of the mordanted, chitosan treated and natural - dyed cotton, silk and acrylics substrates. Natural dyes are extracted from Gromwell by boiled water. Three different compounds of Al, Cu, Sn and Chitosan are used as mordanting agents. The result of this study is summarized as follows: 1. Color of the fabrics dyed with Gromwell changes redder, bluer and darker after chitosan treated and mordanting. 2. After washing, the color of natural dyes changes more light and gray, Chitosan and Cu mordanting gives better colorfastness in washing than any others. 3. All chitosan treated fabrics improve air permeability. 4. In the chitosan treated fabrics, a half life of the static electricity is shown good result.

• IE interfaces
• /
• v.15 no.1
• /
• pp.99-106
• /
• 2002

A recently developed alternative to traditional production planning and control systems such as material requirement planning(MRP) and just-in-time(JIT) is the drum-buffer-rope(DBR). The DBR now being implemented in growing number of manufacturing organizations enables better scheduling and decision making on the shop floor. In implementing the DBR, however, an information system is usually needed to transmit the signal that runs from the constraint to material release. In this paper we propose a different mechanism to transmit the signal in the case that the demand of product is stable, which uses the well-known Kanban system. To improve the reality, this paper shows and example of the Kanban format, its operation, and calculation of the number of Kanbans.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.2
• /
• pp.99-105
• /
• 2008

Multi-leaf springs are widely used for a major suspension component in many commercial vehicles. The modeling technique of multi-leaf springs is one of the most difficult problems in suspension modeling as the elements have complicated nonlinear characteristics such as a hysteresis behavior due to the friction. In this paper, hysteretic characteristics with the static and dynamic test are modeled and are simulated with three links and joints in MSC.ADAMS. Simulation results showed good agreements with test results. Using this methodology, it is expected that dynamic characteristics of suspension system with multi-leaf spring can be more accurately evaluated in vehicle dynamics.

• 유체기계공업학회:학술대회논문집
• /
• 2001.11a
• /
• pp.99-105
• /
• 2001

In this study, the instability of a centrifugal compressor with vaned diffuser was investigated. During unstable operation of the test compressor, pressure fluctuations at different diffuser radius ratios were measured by using high frequency pressure transducers. Two different types of stall, mild and deep stall, were observed alternately and irregularly at some flow rate where the compressor performance was steeply deteriorated. In this transient zone, the size of rotating stall cell was estimated through the Wavelet transform analysis. It was about 45 percents of rotor circumferential space at 3000 rpm and not dependent on flow rate.

• Journal of Korean Association for Spatial Structures
• /
• v.5 no.1 s.15
• /
• pp.99-105
• /
• 2005

The pushover analysis is becoming a popular tool for seismic design of building structures. In this paper the state-of-art on static nonlinear analysis of building structures is presented with the emphasis on the effects of analysis parameters; i. e., lateral load patterns, modeling of members, and analysis computer programs. The analysed results may have variation even if a same structure is analysed. This paper is to investigate how large the variation is and what the main causes of the variation are. The difference of analysed results, the resultant variation of lateral story shear force and flexural strength of structural members are discussed. The pushover analysis procedure are routinely used in the seismic design of building structures, but some problems must yet be clarified, such as the effects to evaluate the parameters of analysis on the basis of a lateral load patterns and modeling of members.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.32B no.12
• /
• pp.1635-1643
• /
• 1995

This paper proposes an algorithm for machine recognition of phonemes in continuously spoken Korean. The proposed algorithm is a static strategy neural network. The algorithm uses, at the stage of training neurons, features such as the rate of zero crossing, short-term energy, and either PARCOR or auditory-like perceptual linear prediction(PLP) but not both, covering a time of 171ms long. Numerical results show that the algorithm with PLP achieves approximately the frame-based phoneme recognition rate of 99% for small vocabulary recognition experiments. Based on this it is concluded that the proposed algorithm with PLP analysis is effective in phoneme recognition.