• Journal of Life Science
• /
• v.16 no.6
• /
• pp.877-883
• /
• 2006

An alternative method to remove and recover heavy metals is biosorption based on metal-sequestering properties of natural or biological origin. In this study, the effects of factors such as temperature, pH, initial concentration of lead, and initial amount of biomass on biosorption of lead using Aureobasdium pullulans were investigated. A. pullulans has an excellent selectivity to remove lead than other heavy metals such as cadmium, chromium, nickel in pure and mixed solution. The optimum temperature of biosorption with A. pullulans was $40^{\circ}C$ and the amount of removal increased at high pH. The higher initial lead concentration or the lower cell dry weight, the higher amount of lead was adsorbed. The adsorption isotherm of lead was accorded with Freundlich model. The adsorption capacity and initial adsorption rate of living A. pullulans were about twice higher than that of dead one.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.285-290
• /
• 2001

There are some of the tools for measuring enterprise and group behavior on construction projects. Of these, performance is vital. But, because of imperfect factors, it came under attack. An enterprise can, however, improve it's problem with performance measurement. For this reason, it is essential tool for achieving objectives of an enterprise. Domestic construction industry must understand that what isn't measured, it not only can't manage it also can't improve. The objective of this study is to investigate the performance measurement tools and items in overseas construction projects(UK, Australia). Based on the data, the study suggests the considerable items, problems and restrictive factors as it is accepted on domestic construction industry.

• Journal of The Korean Association For Science Education
• /
• v.25 no.2
• /
• pp.111-121
• /
• 2005

The purpose of this study was to analyze characteristics of experimental design and evidence choice of the elementary school students in problem solving process related to controlling variable. For this study, 96 6th grade students were selected and tested with Science Reasoning Task. This study revealed that the types of experimental design were categorized as variance of control variable, controlling of causal variable, perfect controlling variable, imperfect controlling variable, variance of all variable. Prior belief had a strong influence on student's experimental design. The types of evidence choice were categorized as perfect controlling variable, controlling causal variable, variance of causal variable. The degree of controlling variable in evidence choice process was much lower than that in experimental design. Most students tended to choose evidence according to prior belief without controlling variable. The results of this study implied that student's prior belief and characteristic of science process skills should be considered to develop program for promoting controlling variable ability.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.4
• /
• pp.313-322
• /
• 2003

In this paper, the reverse link performance of imperfect power controlled cdma2000 cellular system that using array at a base station is analyzed, when MCGM beamforming algorithm and power control error is considered in shadowing. The blocking probability of the cdma2000 cellular system based on array parameters, E$\_$b//N$\_$0/ and interference statistics is calculated, and then the system capacity is calculated at a specific blocking probability. When the blocking probability is set 1 %, PCE(power control error) is 2 dB, M=2, 4, 8, 10, the capacity of cdma2000 is increased 2.3 ∼ 2.5 times higher than IS-95.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.8
• /
• pp.830-838
• /
• 2003

In this paper, TX/RX dual operation microstrip single antenna for satellite communication is designed, analyzed, fabricated and measured. TX/RX frequency ranges are 14.0∼l4.5 GHz, 11.7∼12.75 GHz in respectively and vertical and horizontal polarizations are used for TX and RX. This antenna uses microstrip direct feeding for RX and aperture coupled strip-line feeding for TX and accommodates stacked elements for a high directivity and wide impedance bandwidth. In an analysis of single element, FDTD and MOM was compared and FDTD analysis was more accurate because of the consideration of finite structure and imperfect two ground planes. The proposed structure facilitates generally to an extension of two dimensional array and lower an unwanted radiation by strip-line feed in TX. TX/RX 8${\times}$4 array has a return loss below -10 dB, -14 dB in TX, RX respectively and a gain ranging from 19.1∼20.7 dB in TX, 21.2∼21.8 dB in RX which has a radiation efficiency of 43∼5l %, 52∼57 %.

• Archives of Plastic Surgery
• /
• v.47 no.2
• /
• pp.187-193
• /
• 2020

Upper limb nerve damage is a common condition, and evidence suggests that functional recovery may be limited following peripheral nerve repair in cases of delayed reconstruction or reconstruction of long nerve defects. A 26-year-old man presented with traumatic injury from a wide, blunt wound of the right forearm caused by broken glass, with soft tissue loss, complete transection of the radial and ulnar arteries, and a large median nerve gap. The patient underwent debridement and subsequent surgery with a microsurgical free radial fasciocutaneous flap to provide a direct blood supply to the hand; the cephalic vein within the flap was employed as a venous vascularized chamber to wrap the sural nerve graft and to repair the wide gap (14 cm) in the median nerve. During the postoperative period, the patient followed an intensive rehabilitation program and was monitored for functional performance over 5 years of follow-up. Our assessment demonstrated skin tropism and sufficient muscle power to act against strong resistance (M5) in the muscles previously affected by paralysis, as well as a good localization of stimuli in the median nerve region and an imperfect recovery of two-point discrimination (S3+). We propose a novel and efficient procedure to repair >10-cm peripheral nerve gap injuries related to upper limb trauma.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.5
• /
• pp.65-72
• /
• 2020

To improve the performance of D2D power control algorithm proposed in the previous work, three modified D2D power control algorithms are proposed to compensate the channel estimation error. Then, we evaluate the performance of three modified D2D power control algorithms in the channel estimation error environment. In real channel environment, the channel estimation is not perfect. To that end, the impact of imperfect channel estimation on the D2D power control algorithm, which was developed with the assumption of perfect channel estimation, has been analyzed in the previous work. Three modified D2D power control algorithms are based on 1) Retransmission, 2) SIR Margin, and 3) Retransmission and SIR Margin. Simulation results show that the Retransmission and SIR Margin approach shows best performance in the sense of the transmit power consumption and the latency.

• Journal of Sasang Constitutional Medicine
• /
• v.10 no.1
• /
• pp.311-341
• /
• 1998

The objective of this article is to induce that the conception of 'Qi-jul(氣質) and Qi-pum(氣稟)' was introduced to the Sasang(四象) Constitutional Medicine from bibliographic study on the theory of 'Qi-pum(氣稟)'. The conclusions summerized as followings. 1. In the oriental medicine, qualitative difference of 'zheng-qi(正氣)' among the individuals, the opposing power against a disease, is regarded as constitution. Having been used as 'nature(素)', 'quality(質)' and 'character(氣質)' in the oriental medical book, the word of 'Che-Jil(體質)' was used in good earnest at the end of 'Qing(情)' dynasty. 2. The nature(性) is divided into two, original nature(本然之性) and charicteristic nature(氣質之性) in the 'New confucianism(新儒學)' and the former means a principle(理), is a pure and good thing and used as a conception of universality, the latter is a principle of character and a imperfect imitation of principle(理). 3. It was repeatedly confirmed that 'Qi-jil and Qi-pum' meant the difference among the individuals by the dispute of 'Li-Qi(理氣)' caused by Lee Hwang(李滉) and Lee Yi(李耳) and by that of 'Ho-Rak(湖洛)' in the Ch'o-son(朝鮮) dynasty. 4. Han Sok-Ji, based on Meng-Zi(孟子)'s doctrine that man's inborn nature is good, criticized the theory of 'Qi-pum' which was 'Zhu-Zi(朱子)'s opinion and his opinion about the life(命) was thought to clue to the classification of the 'Sasang(四象)' invented by Lee Je-Ma as Park Se-Dang's theory that everyone has common nature but has different life(命). 5. By introducing the theory of 'Qi-pum' and the conception of life(命) which was understood as a special character by Han Sok-Ji and Park Se-Dang to Sa-sang constitutional medicine, Lee Je-Ma explained the reason why each man who was classified four constitutions, 'Taiyang'(太陽), 'Taiyin'(太陰), 'Shaoyang'(少陽), 'Shaoyin'(少陰), had the different formation of the visceral department(臟局).

• Archives of Pharmacal Research
• /
• v.28 no.3
• /
• pp.351-357
• /
• 2005

Endosulfan is one of the organochlorine pesticides, which are well-known endocrine disruptors (EDs), and it acts as an estrogen agonist. Estrogen is a group of hormones that play an important role in mammary gland function and are implicated in mammary carcinogenesis. In the present study, we studied the effects of endosulfan on nodule like alveolar lesion (NLAL) formation in mouse mammary gland development using a mouse mammary gland organ culture (MMOC) system. Although endosulfan-treated mammary glands did not form NLALs, more alveolar buds were formed in this group than in the negative control (vehicle-treated) group. In addition, telomerase reverse transcriptase (TERT) mRNA expression levels were increased in endosulfan-treated mammary glands in a dose-dependent manner. Telomerase can be activated by estrogen, therefore, we examined the effects of endosulfan on telomerase activity, and found that the telomerase activity in estrogen receptor-positive MCF-7 cells was up-regulated by endosulfan treatment. Moreover, this activation was accompanied by the up­regulation of the TERT mRNA expression. Also, transient expression assays using CAT reporter plasm ids containing various fragments of the TERT promoter showed that this imperfect palindromic estrogen-responsive element is almost certainly responsible for the transcriptional activation by endosulfan. These results may help elucidate the endocrine disrupting mechanism of endosulfan.

• Journal of Veterinary Clinics
• /
• v.20 no.1
• /
• pp.7-11
• /
• 2003

The selection of a test as a reference with no perfect sensitivity and specificity may lead to bias, yielding distortion of the diagnostic performance. This means it is inappropriate to use imperfect diagnostic tests as a reference method to identify infected patients in clinical environments. In this study, diagnostic performance of rapid urease test, polymerase chain reaction (PCR), and histology of gastric biopsy specimens for diagnosing Helicobacter pylori infection separately and in combination was estimated by using non-linear regression. Based on this approach, the sensitivity, specificity and likelihood ration positive and negative values for each test were as follows: urease test 99.9%, 99.9%, 99.9%, 99.6%, respectively; PCR 88.6%, 99.9%, 99.9%, 70.5%, respectively; histology 78.3%, 97%, 78.3%, 97%, respectively. Predictive values for positive and negative changes with varying Combination of three diagnostic tests employed in the study gives no substantial benefit for practitioners to screen infected patients, and urease test or PCR represents an appropriate single test in clinical environments.