• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.11 s.353
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• pp.58-68
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• 2006

This work proposes a 10b 250MS/s $1.8mm^2$ 85mW 0.13um CMOS A/D Converter (ADC) for high-performance integrated systems such as next-generation DTV and WLAN simultaneously requiring low voltage, low power, and small area at high speed. The proposed 3-stage pipeline ADC minimizes chip area and power dissipation at the target resolution and sampling rate. The input SHA maintains 10b resolution with either gate-bootstrapped sampling switches or nominal CMOS sampling switches. The SHA and two MDACs based on a conventional 2-stage amplifier employ optimized trans-conductance ratios of two amplifier stages to achieve the required DC gain, bandwidth, and phase margin. The proposed signal insensitive 3-D fully symmetric capacitor layout reduces the device mismatch of two MDACs. The low-noise on-chip current and voltage references can choose optional off-chip voltage references. The prototype ADC is implemented in a 0.13um 1P8M CMOS process. The measured DNL and INL are within 0.24LSB and 0.35LSB while the ADC shows a maximum SNDR of 54dB and 48dB and a maximum SFDR of 67dB and 61dB at 200MS/s and 250MS/s, respectively. The ADC with an active die area of $1.8mm^2$ consumes 85mW at 250MS/s at a 1.2V supply.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.347-358
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• 2009

Recently, it is getting into a good situation for the flat-plate slab system to be applied. The flat-plate slab without beam, however, is often too weak to control deflection properly compared to other typical slab-beam structures, for which the post-tension method is generally regarded as one of best solutions. The post-tension (PT) method can effectively control deflection without increase of slab thickness. Despite this good advantage, however, the application of PT method has been very limited due to cost increase, technical problems, and lack of experiences. Therefore, in order to reduce difficulties on applying full PT method under the current domestic circumstances and to enhance constructability of PT system, this research proposed the partial PT method with top jacking anchorage applied in a part of span as need. For the top jacking anchorage system, the efficiency of deflection control shall be considered in detail because it can vary widely depending on the location of anchorage that can be placed anywhere as need, and tensile stresses induced at back of the anchorage zone also shall be examined. Therefore, in this study, analysis were performed on the efficiency of deflection control depending on the location of anchorage and on tensile stresses or forces using finite element method and strut and tie model in the proposed top jacking anchorage system. The proposed jacking system were also applied to the floor slabs at a construction site to investigate its applicability and the analysis results of slab behavior were compared to the measured values obtained from the PT slab constructed by the partial PT method. The result of this study indicates that the partial PT method can be very efficiently applied with little cost increase to control deflection and tensile stresses in the region as a need basis where problem exists.

• Journal of Dairy Science and Biotechnology
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• v.32 no.1
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• pp.47-53
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• 2014

In this study, our aim was to investigate the changes in ginsenosides and polyphenols in red ginseng extract fermented by Lactobacillus acidophilus and to manufacture fresh cheese using fermented red ginseng extract. Red ginseng extract (3%, w/v) was fermented by L. acidophilus for 24 h. On performing lactic acid bacteria counts, we determined that L. acidophilus reached its maximum growth phase after 16 h; this was followed by decrease in growth. During fermentation, the levels of ginsenosides Rg3 (20S) and Rg3 (20R) as well as protopanaxadiol (20R), F1, and compound K increased, while those of s Rb2, Rd, Rf, and Rg1 decreased. The pH, titratable acidity, and viable cell counts in fresh cheese prepared using fermented red ginseng extract were measured during the storage period. The pH decreased over time, while titratable acidity and viable cell counts increased with increase in the duration of the storage period. Sensory tests showed that the overall sensory properties of fresh cheese prepared using 1% fermented red ginseng extract were similar to those of the control groups. This result suggests that L. acidophilus-fermented red ginseng has potential for development as a new bioactive material.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.188-204
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• 1977

The studies on the saponins of Korean ginseng, Panax ginseng C.A. Meyer, were performed according to the cultivating locations, sampling seasons, plant parts, and growing stages. The changes in saponin content in the course of manufacturing Red ginseng and Ginseng extract were observed. In this paper, a new method for the determination of the total and the individual saponin glucosides was proposed and applied to the samples under study. The method employing Digital Densitorol DMU-33C (Toyo electric Co., Japan) followed the separation of the saponins by means of a preparative thin layer chromatography. The saponin contents and their fractional distribution were summarized as follows: 1. The average concentrations(% plant dry weight) of semi-purified saponins in the roots of Korean ginseng planted in the various locations were 5.0%(Keumsan), 6.0% (Kimpo), and 5.4% (Pocheon), respectively. 2. There were 3.3% saponins in White ginseng(Rhizome) and 12.7% saponins in Ginseng tail (Fibrous root). 3. Regarding the year of growth, the contents of saponins were 90.3mg (2-year-old ginseng), 254.4mg (3-year-old ginseng), 404.2mg (4-year-old ginseng). 999.6mg (5-year-old ginseng), and 1377.1mg (6-year-old ginseng) respectively, and the saponin factions containing panaxatriol as an aglycone increased. 4. Thin layer chromatography revealed that Red ginseng yielded many saponins which Shibata et al. designated as $ginsenoside-Rb_1$ (22.1%), $-Rb_2(15.4%)$, -Rc(12.6%), -Re (15.7%), and $-Rg_1$, (9.3%). 5. 29.9% of crude saponins were isolated from ethanolic extract of Panax ginseng fibrous root and their extraction yield was 94.2% of fibrous root saponin.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.43-53
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• 2004

The current Korean Concrete Design Code(KCI Code) requires the minimum and maximum content of shear s in order to prevent brittle and noneconomic design. However, the required content of the steel reinforcement In KCI Code is quite different to those of the other design codes such as fib-code, Canadian Code, and Japanese Code. Furthermore, since the evaluation equations of the minimum and maximum shear reinforcement for the current KCI Code were based on the experimental results, the equations can not be used for the RC members beyond the experimental application limits. The concrete tensile strength, shear stress, crack inclination, strain perpendicular to the crack, and shear span ratio are strongly related to the lower and upper limits of shear reinforcement. In this research, an evaluation equation for the minimum content of shear reinforcement is theoretical proposed from the Wavier's three principals of the mechanics of materials.

• Korean Journal of Head & Neck Oncology
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• v.14 no.2
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• pp.236-243
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• 1998

Objectives: Local invasion of the thyroid cancer that is invasion of the upper aerodigestive tract, neurovascular structures of the neck and superior mediastinum, is infrequent and comprises of 1-16% of well-differentiated thyroid cancer. However the proximity of the thyroid gland to these structures provides the means for an invasive cancer to gain ready access into theses structures and when invasion occurs, it is the source of significant morbidity and mortality. So locally invasive thyroid cancer should be removed as much as possible, but still much debates have been exist whether the surgical method should be radical or conservative. This study was desinged to evaluate the clinical characteristics and the surgical treatment of the locally invasive thyroid cancer. Material and Methods: At the department of otorhinolaryngology of Hallym university, 10 patients diagnosed as locally invasive thyroid cancer among the 81 patients treated for thyroid cancer between 1991 to 1997 were retrospectively evaluated. Results: Of the 10 patients, 3 patients had histories of previous surgical treatment with or without radiation or radioactive iodine therapy. The site of invasion of thyroid cancer were trachea(7 cases), recurrent laryngeal nerve(5 cases), mediastinal node(5 cases), esophagus(3cases), larynx(3cases), carotid artery(3 cases), pharynx(l case), and other sites(4 cases). The operation techniques included 1 partial laryngectomy and 1 partial cricoid resection, 2 shavings and 3 window resections of the trachea, 1 sleeve resection of the trachea with end-to-end anastomosis and 1 cricotracheoplasty for tracheal invasion, 2 shavings and 1 partial esophagectomies for esophageal invasion, and 1 wall shaving and 2 partial resections with $Gortex^{\circledR}$ tube reconstruction for carotid artery invasion, and so on. Conclusions: These data and review of literature suggest that the surgical method should be perfomed on the basis of individual condition and complete removal of all gross tumor with preservation of vital structures whenever possible will offer a good result.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.233-240
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• 2005

To discover new functional materials using edible plants, antioxidant activities of methanol extracts from various parts of seven wild vegetables were investigated in vitro. Total polyphenol contents, determined by Folin-Denis method, varied from 16.74 to $130.22{\mu}g/mg$. Radical-scavenging activities of methanol extracts were examined using ${\alpha},\;{\alpha}-diphenyl-{\beta}-pirrylhydrazyl$ (DPPH) radicals and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) assay. Inhibition effects on peroxidation of linoleic acid determined by ferric thiocyanate (FTC) method and on oxidative degradation of 2-deoxy-D-ribose in Fenton-type reaction system were dose-dependent. Athyrium acutipinulum Kodama (leaf and rood), Achyranthes japonica (Miq.) Nakai (seed), and Solidago virga-aurea var. gigantea Nakai (root) showed relatively high antioxidant activities in various systems.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.480-485
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• 2019

The present study was conducted to compare antioxidant capacities of protein hydrolysates from four different edible insects (Protaetia brevitarsis larvae, Allomyrina dichotoma larvae, Gryllus bimaculatus imago, and Tenebrio molitor larvae) which have recently been registered as food varieties in Korea. Protein hydrolysates were prepared from each insect using enzymatic hydrolysis using alcalase, and were then separated into a fraction containing ${\leq}3kDa$. According to $RC_{50}$ values and trolox equivalent antioxidant capacity results obtained from five different antioxidant analyses, the Gryllus bimaculatus (GB) hydrolysate showed relatively high levels of antioxidant capacity and, in particular, the GB hydrolysate showed considerably strong antioxidant activities in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and in ferric reducing antioxidant power (FRAP) assays. The GB hydrolysate also showed the strongest inhibitory effect on peroxidation of linoleic acid, and its rate of inhibition at $100{\mu}g/mL$ on day 3 of treatment was 60.26%. These results suggest that protein hydrolysates from edible insects including GB represent potential sources of natural antioxidants.

• Food Science and Preservation
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• v.14 no.2
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• pp.220-225
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• 2007

This study was performed to measure the antioxidative, antimutagenic, and cytotoxic properties of Prunus armeniaca using the DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical donating method, the Ames test, and cytotoxicity measurements, respectively. Electron-donating abilities were 48.3, 43.9, 14.8 and 12.9 per g dry matter of P. armeniaca seed (PAS), P. armeniaca flesh(PAF), butylated hydroxytoluene, and ${\alpha}-tocopherol$, respectively. The direct antimutagenic effects of an ethanol extract of P. armeniaca were examined in Ames tests using Salmonella typhimurium TA98 and TA100 as reporter organisms. In the Ames test, the ethanol extract of P. armenicaca alone did not exhibit any mutagenicity but the extract did show substantial inhibitory effects against mutations induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and 4-nitroquinoline-1-oxide(4NQO). The ethanol extract of PAS(200g dry matter/plate) inhibited strain TA98 mutagenesis induced by 4NQO by ca. 37.9%, and mutation inhibition values of 42.1% and 69.4%, respectively, were observed when 4NQO and MNNG acted on the TA100 strain. The cytotoxic effects of ethanol extracts of P. armeniaca against cell lines of human lung carcinoma(A549), human breast adenocarcinoma(MCF-7), human hepatocellular carcinoma(Hep3B), human cervical adenocarcinoma(HeLa), and human gastric carcinoma(AGS) rose with increases in extract concentration. An ethanol extract(4mg/mL dry matter) of PAF showed strong cytotoxicities of 88.2%, 58%, 72.8%, 89.4%, and 91.9% against A549, AGS, MCF-7, HeLa, and Hep3B cells, respectively. In contrast, the same extract showed only 13 37% cytotoxicity for a nomal human kiney cell line(293). It is suggested that P. armeniaca possesses useful antioxidative, antimutagenic, and anticancer properties.

• Food Engineering Progress
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• v.21 no.4
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• pp.351-359
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• 2017

This study investigates the quality characteristics of dough and bread added with 6% chestnut shell powder and extruded chestnut shell powder at various conditions. As extrusion process variables, melt temperature ($110^{\circ}C$, $130^{\circ}C$, $150^{\circ}C$) and moisture (25% and 30%) were controlled. Total dietary fiber content was slightly increased in extruded chestnut shell powder group. In the farinogram, absorption was significantly increased in the group of 25% moisture content and 30% moisture content (p<0.05). After 2 hours and 3 hours, the leavening heights of dough for control showed a similar tendency to that of dough with extruded chestnut shell at a melt temperature $150^{\circ}C$ and with moisture content of 25% and 30%. Specific volume was the highest at a control of $3.74{\pm}0.08cc/g$ and extruded chestnut shell powder group was slightly higher than the chestnut shell powder group. Firmness after 1 day on control of $107.42{\pm}14.52g$ was similar to that of the bread with extruded chestnut shell at a temperature of $150^{\circ}C$ and moisture content of 25% for $113.33{\pm}6.17g$. In conclusion, the extrusion-cooking of chestnut shell powder improved the quality characteristics of dough and bread. The optimum combinations of conditions in tested range were melt temperature at $150^{\circ}C$ and moisture content at 25%, and melt temperature at $130^{\circ}C$ and moisture content at 30%.