• Review of KIISC
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• v.17 no.6
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• pp.30-40
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• 2007

최근의 국내 정보보호 인증체계는 암호검증제도의 시행과 CCRA 가입으로 큰 변화를 맞이하였다. 이런 변화는 국가기관의 정보보호제품 도입체계에도 많은 영향을 미치고 있다. 본 고에서는 정보보호제품 인증 체계 변화, 이 후의 개편된 보안적합성 검증제도에 대한 간략히 소개하고, 보안적합성 검증제도와 암호검증제도의 신청을 위한 제출 문서 작성법을 제시하여, 보안적합성 검증제도와 암호검증제도 신청 또는 연 도움을 주고자 한다.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.159.1-159.1
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• 2001

• Journal of the Korean Chemical Society
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• v.29 no.2
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• pp.178-182
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• 1985

The purpose of this study was to develop a separation method of Zn(II), Cu(II) and Mg(II), by ion exchange chromatography using cation exchange resion (Dowex 50w${\times}$8, 80-100 mesh) and anion exchange (Amberlite IRA-400). Ion exchange resions were packed into 25 ${\times}$ 2cm ID column and flow rate was controlled to 0.30 ml/min. Good eluents for separation of nonferrous metal ions such as Zn(II), Cu(II), Mg(II) were as follow: 0.5M $NaNO_3$ (pH 3.1), 0.2~0.5M HCl + 50~60% Acetone, and 1M HAc + 0.1M NaAcf(pH 3.7) aqueous solution. The mixed solution of 0.1M NaAc(pH 3.7), 0.5M HCl + 50% Acetone were found to be the best eluent for step elution. Analysis of metals were determined by atomic absorption spectrophotometer. In addition, separated Zn(II) fraction was obtained by eluted with 0.12N HCl and 1.5N $NH_4OH$ aqueous solution. This solution was titrated by the E. D. T. A.

• Journal of the Korean Chemical Society
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• v.29 no.2
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• pp.137-143
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• 1985

Construction of a liquid membrane type of cupric ion selective electrode and its application to the potentiometric titration have been studied. A liquid ion-exchange membrance was prepared by extracting Cu(II) in aqueous solution into 1-(2-pyridylazo)-2-naphthol/nitrobenzene. A Ag/AgCl internal reference electrode was dipped into the aqueous reference solution of $1.00 {\times} 10^{-3}M\;Cu(NO_3)_2$ buffered with HAc-NaAc buffer solution, which was in contact with the nitrobenzene extract. The electrode showed the nernstian response to Cu(II) in the concentration range from $1.00{\times} 10^{-6}$ to $1.00{\times} 10^{-3}$M. The most suitable ion-exchanger concentration in the liquid membrane was $1.00{\times} 10^{-4}$M. The selectivity coefficients of the electrode for the various metal cations were investigated. The electrode was applied to the potentiometric titration of Cu(II) with EDTA.

• Natural Product Sciences
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• v.22 no.4
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• pp.299-306
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• 2016

This study aimed to establish the quantitative method to analyze the content of peroxynitrite-scavengers belonging to polyphenols in six Korean Quercus species (Quercus mongolica, Q. dentata, Q. acutissima, Q. alienta, Q. serrata, and Q. variabilis) by HPLC. The twelve peroxynitrite-scavengers, flavanols (catechins: (+)-catechin, (-)-epicatechin, and (-)-epigallocatechin), flavonols (kaempferol and quercetin), flavonol glycosides (astragalin, quercitrin, and isoquercitrin), flavonol acylated glycosides (astragalin 6''-gallate and isoquercitrin 6''-gallate), gallic acid and its dimer (ellagic acid) were analyzed by HPLC. Further, anti-Alzheimer's activity was assayed in a passive avoidance testusing mice by measuring the retention latency (sec), the concentration of acetylcholine (ACh), and acetylcholinesterase (AChE) activity. Simultaneous analysis of the extracts of the six Quercus leaves was achieved on a Capcell C18 column ($5{\mu}m$, $250mm{\times}4.6mm\;i.d.$) with a gradient elution of 0.05% HAc and 0.05% HAc in $CH_3CN$. In the extract of Q. mongolica leaves, the content of gallic acid (32.53 mg/g), (+)-catechin (28.78 mg/g), (-)-epicatehin (22.03 mg/g), astragalin 6''-gallate (20.94 mg/g), and isoquercitrin 6''-gallate (44.11 mg/g) and peroxynitrite-scavenging activity ($IC_{50}$, $0.831{\mu}g/ml$) were high. This extract delayed the retention latency and inhibited acetylcholinesterase activity in scopolamine-induced memory impairment of mice, suggesting that it has anti-Alzheimer's activity.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.116-122
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• 1990

In order to improve the shelf life of Tofu, the effect of calcium chloride or acetic acid as coagulants were investigated for microbial and physicochemical changes during the storage in different kinds of soaking solution. The soaking water of Tofu prepared from calcium chloride was found to be spoiled after 15-17 hours of storage at $30^{\circ}C$, by reaching the bacteria count to 10million per ml. The shelf life of the Tofu prepared from acetic acid was better than those prepared by calcium chloride. For the effect of soaking solution on storage life, soaking Tofu in 0.1% acetic acid was found to be more effective than soaking in other solutions of 3% NaCl or 0.1% K-sorbate. The optical density of soaking solution of Tofu increased in proportion to spoilage, and in case of soaked Tofu in 3% sodium chloride and 0.1% K-sorbate solution, it greatly increased. Titratable acidity, and amino nitrogen contents in soaking solution increased as spoilage of Tofu progressed, but pH decreased the early period, one or two days, of stored Tofu and then increased.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.397-402
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• 2006

The treatment characteristics of leachate produced from pretreatment facilities like composting and feeding were investigated in a mesophilic anaerobic treatment. Experiments were performed in two phase which were acidification and methane fermentation. The acidification step was optimized for OLR from 1 to $4.5kg\;COD/kg\;VS{\cdot}day$ without adding NaOH. As experiment dates became longer, the solubilization ratio of particles increased up to 30% over 70 days. TVA was generated up to maximum 9,970mg HAc/L at OLR of $2kg\;COD/kg\;VS{\cdot}day$. But TVA was generated to minimum 6,519mg HAc/L at OLR of $4.5kg\;COD/kg\;VS{\cdot}day$. The acidification ratio was analyzed from 10.9% to 3.8% at OLR of $2kg\;COD/kg\;VS{\cdot}day$ and $4.5kg\;COD/kg\;VS{\cdot}day$ respectively. After 55 days, salt contents in the acid fermenter were accumulated and stabilized at the concentration of 3,150mg/L. Sodium ion($Na^+$) concentration was stabilized at 1,300mg/L. At methane fermentation step, biogas was generated up to 750ml and 937.5ml at the feeding volume of 20ml and 25ml respectively for acid fermented liquid during 25 days. About 80% of total biogas was generated during early 15 days and 95% were generated during 18 days respectively. After 25 days of the BMP test, acetic acid was removed approximately 97% and 98%, in case of those two experimental conditions.

• Journal of Welding and Joining
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• v.34 no.6
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• pp.42-46
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• 2016

Hydrogen assisted cracking (HAC) is one of the most complicated problem in welding. Huge amount of studies have been done for decades. Based on them, various standards have been established to avoid HAC. But it is still a chronic problem in industrial field. It is well known that the main causes of the hydrogen crack are residual stress, crack susceptible micro structures and a certain critical level of hydrogen concentration. Even though the exact generating mechanism is unclear till today, it has been reported that the hydrogen level in the weld metal should be managed less than a certain amount to prevent it. Matsuda studied that the residual hydrogen level in the weld metal can be varied even if the initial hydrogen content is same. It is also insisted in this report that the residual hydrogen concentration is in stronger correlation with hydrogen crack than the initial hydrogen content. But, in practical point of view, the residual hydrogen is still hard to consider because measuring hydrogen level is time and cost consuming process. In this regard, numerical analysis is the only solution for considering the residual hydrogen content. Meanwhile, Takahashi showed the possibility of predicting the residual hydrogen by a rigorous FE analysis. But, few commercial software suitable for solving the weld metal hydrogen has been reported yet. In this study, two dimensional thermal - hydrogen coupled analysis was developed by using the commercial FE software MARC. Since the governing equation of the hydrogen diffusion is similar to the heat transfer, it is shown that the heat transfer FE analysis in association with hydrogen diffusion property can be used for hydrogen diffusion analysis. A series of simulation was performed to verify the accuracy of the model. For BOP (Bead-On-Plate) and the multi-pass butt welding simulations, remaining hydrogen contents in the weld metal is well matched with measurements which are referred from Kim and Masamitsu.

• Journal of Korean Neurosurgical Society
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• v.64 no.4
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• pp.619-630
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• 2021

Objective : The skull base reconstruction step, which prevents cerebrospinal fluid (CSF) leakage, is one of the most challenging steps in endoscopic skull base surgery (ESS). The purpose of this study was to assess the outcomes and complications of a reconstruction technique for immediate CSF leakage repair using multiple onlay grafts following ESS. Methods : A total of 230 consecutive patients who underwent skull base reconstruction using multiple onlay grafts with fibrin sealant patch (FSP), hydroxyapatite cement (HAC), and pedicled nasoseptal flap (PNF) for high-flow CSF leakage following ESS at three institutions were enrolled. We retrospectively reviewed the medical and radiological records to analyze the preoperative features and postoperative results. Results : The diagnoses included craniopharyngioma (46.8%), meningioma (34.0%), pituitary adenoma (5.3%), chordoma (1.6%), Rathke's cleft cyst (1.1%) and others (n=21, 11.2%). The trans-planum/tuberculum approach (94.3%) was the most commonly adapted surgical method, followed by the trans-sellar and transclival approaches. The third ventricle was opened in 78 patients (41.5%). Lumbar CSF drainage was not performed postoperatively in any of the patients. Postoperative CSF leakage occurred in four patients (1.7%) due to technical mistakes and were repaired with the same technique. However, postoperative meningitis occurred in 13.5% (n=31) of the patients, but no microorganisms were identified. The median latency to the diagnosis of meningitis was 8 days (range, 2-38). CSF leakage was the unique risk factor for postoperative meningitis (p<0.001). Conclusion : The use of multiple onlay grafts with FSP, HAC, and PNF is a reliable reconstruction technique that provides immediate and complete CSF leakage repair and mucosal grafting on the skull base without the need to harvest autologous tissue or perform postoperative CSF diversion. However, postoperative meningitis should be monitored carefully.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.143-162
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• 2021

Research on consumers' perception and willingness to purchase Battery Electric Vehicles (BEVs) is necessary to simulate BEVs' deployment in South Korea because South Korea's BEVs market is still in the early stage. This paper derives a theoretical framework for consumer segmentation based on consumers' willingness to purchase before and after BEV usage experience. In particular, this study empirically evaluates consumers' willingness to purchase and concerns using the survey data from BEVs users in either Seoul or the Jeju region. The empirical results from logit models show that experienced consumers' concerns about the heater and air conditioning (HAC) in BEVs decreased the consumers' willingness to buy, while greater daily driving distances increased the consumers' willingness to buy. In addition, the empirical findings from ordered probit models show that experienced consumers' concerns about the short driving distance, the availability of maintenance service (i.e., A/S service) during unexpected events, and the difficulties of driving BEVs up-hill increased the degree of concern about HAC. This paper will provide insights related to consumer segmentation, R&D, marketing strategies, and policy design for policymakers and firms.