• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.13 no.2
• /
• pp.41-47
• /
• 2003

Revocation scheme is a re-keying scheme for dynamically changing group in multicast environment. In this paper, we propose two variants of the previously proposed revocation scheme, on the purpose of reducing the amount of computations group members should perform. Also proposed is a method of allowing unlimited number of member revocations.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.11 no.5
• /
• pp.31-42
• /
• 2001

Two important requirements in broadcast encryption schemes are traitor traceability and revocability. In this paper, we propose a new type of a traitor tracing scheme that can revoke an unlimited number of traitors\` personal keys. Additionally, we propose an efficient and simple method to provide self-enforcement property. We also describe a variant of our scheme of which encryption algorithm is secure against adaptive chosen ciphertext attacks.

• Annual Conference of KIPS
• /
• 2020.11a
• /
• pp.75-77
• /
• 2020

코로나19로 사회적 거리두기가 지속되면서 코로나 블루를 적절히 해소하는 방안 또한 새로운 사회적 무제로 대두되었다. 이에 본 연구는 전자출입명부 시스템을 활용하여 안전하게 지역을 관광할 수 있는 방안을 제시하였다. 구체적으로 QR코드에 기록된 정보를 바탕으로 지역별로 방문한 관광객의 숫자를 공유하여 지역별 방문인구를 파악할 수 있도록 하였다. 이를 통해 관광객은 밀집된 공간을 피하며 방역지침을 준수하면서도, 다양한 지역을 방문하며 코로나 블루를 해소할 수 있을 것이다.

• Annual Conference of KIPS
• /
• 2008.05a
• /
• pp.1163-1166
• /
• 2008

소프트웨어 소스코드는 크게 오픈 소스와 상업용 비공개 소스로 구분될 수 있다. 소스코드는 자동차 조립라인과 같이 소프트웨어를 무제한 생산이 가능한 지식집약적인 부가가치 산업이다. 본 논문에서는 오픈-소스 코드에는 디지털라이센스를 이용한 저작권을 표현하고, 비공개-소스 코드는 보안 컨테이너 역할을 수행하는 크립텍스 모델을 제안한다.

• Korean Journal of Weed Science
• /
• v.2 no.1
• /
• pp.7-12
• /
• 1982

The experiment was studied to know the competitive ability of rice against weeds as affected by rice maturity and plant spacing. For both cultivars, Tongil (12 days later) and Yeongnamjosaeng, the least amount of weed was obtained from the 10 ${\times}$ 10cm plant spacing while no difference between 40 ${\times}$ (10 ${\times}$ 10cm) and 30 ${\times}$ 15cm plant spacings was observed. When weed was nor pulled out by hand, significant yield loss was resulted in 30 ${\times}$ 15cm and 40 ${\times}$ (10 ${\times}$ 10cm) plant spacings while no difference between weeding regime was observed at the 10 ${\times}$ 10cm plant spacing in both cultivars. Rice grain yield was unaffected by plant spacing for hand weeded plot in both rice cultivars. For noweeding plot, however, the highest grain yield was obtained from 10 ${\times}$10cm plant spacing and also this yield was not significantly different from the yield of hand weeded plot while significant yield loss was recognized at the 30 ${\times}$ 15cm and 40 ${\times}$ (10 ${\times}$ 10cm) plant spacings in noweeding plot. There was also a good relationship between weed weight and grain yield for both cultivars (Tongil; Y = 5.68 - 0.0127 X, r = -0.814$^*$; Yeongnamjosaengv Y = 5.04 - 0.0314 X, r =-0.9704$^{**}$). Based on these relationship, weed weight of 188.2g/sq.m for Yeongnamjosaeng and 223.6g/sq.m for Tongil was needed to reduce rice yield by 50%, respectively. This result implied that Tongil compete more efficiently against weed than Yeongnamjosaeng and hence, could be concluded that late maturing cultivar was more competitive against weed compared to early maturing cultivar.

• Journal of Animal Science and Technology
• /
• v.49 no.1
• /
• pp.41-50
• /
• 2007

Data from a comparative slaughter experiment with two hundreds of Korean native (Hanwoo) beef steers were utilized to determine net energy and protein requirements for growth (NEg and NPg). Eight randomly selected steers were used in the initial slaughter group of 6 month of age and the remaining steers allocated to treatments within two groups. The restricted groups were fed 1.2 to 1.5% concentrate per kg body weight (BW) in the growing period (6～12 month of age), 1.7 to 1.8% concentrate per kg BW in the early fattening period (13～18 month of age), and concentrate feed ad libitum in the late fattening period (19～30 month of age). Ad libitum groups were fed concentrate ad libitum through the whole period. Rice straw was offered ad libitum for 24 month of two feeding systems. The steers were slaughtered when animals reached every 2 month from 8 to 30 month of age. For all body composition determinations, whole empty body components were weighed, taken each proportional subsample was ground for chemical analysis. Equations developed with the pooled data to predicted NEg and NPg were similar to the equations of Japanese Feeding Standard for Beef Cattle (2000). First equations were developed to predicted NEg; NEg = 0.05332×LBW0.75×DG for restricted treatment and NEg = 0.04912×LBW0.75×DG for ad libitum treatment. Second equations were developed to predicted NPg; NPg = DG × (224.7－0.251×LBW) for restricted treatment and NPg=DG×(210.1－0.214×LBW) for ad libitum treatment.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.4
• /
• pp.539-549
• /
• 2012

In order to acquire basic data on the development of squid processing food, we investigated changes in the composition of boiled squid upon heat treatment ($100^{\circ}C$), acid treatment (acetic acid, 0~5%), and pre-boiling ($55^{\circ}C$, $80^{\circ}C$). The proximate composition of squid was 73~78% moisture and 19~24% crude protein, treatment with acid solution had a significant effect on the proximate composition of boiled squid (p<0.05). The major free sugars were ribose and glucose in all treatment samples. The $55^{\circ}C$ pre-boiled sample had lower levels of glucose than the other samples. The total free sugar content of the non-peeled sample was the highest, followed by the $80^{\circ}C$ pre-boiled sample, whereas the sugar content in the $55^{\circ}C$ pre-boiled sample was very low. With regards to amino acid content, proline was the highest in all samples, followed by taurine and histidine. Treatment with acid solution had a significant effect on the total free amino content of boiled squid (p<0.05). The total free amino acid content of the $55^{\circ}C$ pre-boiled sample was the highest, followed by the $80^{\circ}C$ pre-boiled sample and non-peeled sample. Inosine and related compounds were not detected in any of the samples, and the adenosine triphosphate (ATP) content was low. The hypoxanthine contents of the $55^{\circ}C$ and $80^{\circ}C$ pre-boiled samples were the highest, the adenosine monophosphate (AMP) and inosine monophosphate (IMP) contents were similar, and the IMP content of the non-peeled sample was higher than those of the peeled samples. The palmitic acid content was very high and constituted 40% of total saturated fatty acids. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents were also high and constituted 60% of total unsaturated fatty acids. Of these, DHA content was the highest, followed by palmitic acid and EPA, which accounted for about 85% of total fatty acids. No difference in fatty acid content was observed between acid treatment and pre-boiling. The mineral P content was the highest on average in all boiled squid samples, followed by K, Na, Mg, and Ca contents. In addition, the pre-boiling temperature and acid solution concentration had significant effects on the mineral content. Further, heavy metal, Cd, Pb, and As contents were detected only at trace amounts, and their levels were lower than standard and permissible amounts for food.

• Journal of Animal Science and Technology
• /
• v.48 no.1
• /
• pp.69-76
• /
• 2006

This study was conducted to evaluate the effects of feeding rye silage and feed restriction on both growth and reproductive performances in replacing gilts. Twenty four replacing gilts (Landrace×Yorkshire, 67.63±1.17kg initial BW) were used in 49 d growth assay. Dietary treatments were included 1) CON(basal diet), 2) S15(15% feed restriction + ad libitum rye silage) and 3) S30(30% feed restriction + ad libitum rye silage). In growth performance, average daily gain and average daily feed intake were the highest in CON among treatments(P<0.05). Average daily silage intake was not significantly different between S15 and S30 treatments(P>0.05). Feed conversion ratio was the lowest in CON among treatments(P<0.05). Average silage intake of S15 and S30 treatments was increased as time goes by(P<0.05). While all gilts of S15 and S30 treatments became pregnant, one gilt of CON became pregnant. Also, first estrus and mating were occured earlier in S15 and S30 than those of CON. In conclusion, 15% feed restriction and feeding rye silage reduced growth performance, reached earlier to first estrus and increased pregnancy rate in replacing gilts.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.11
• /
• pp.394-401
• /
• 2019

This study examined the effects of restricted feeding on the growth performance, carcass characteristics, and economic efficiency of finishing pigs for 27 days. A total of 24 finishing pigs (Landrace×Yorkshire×Duroc, average initial body weight of 81.52±1.11 kg) were allotted randomly to two treatments with 12 replicates (one pig per replicate). The experimental treatments were ad libitum feeding (AF), and restricted feeding (RF) with a 10% increase in offered feed than the day before if required. The results showed that the average daily feed intake (ADFI; p<0.001) of the pigs were improved in the RF treatment, but there were no changes in the average daily gain and weight gain to feed intake ratio (G:F). There were no significant differences in carcass weight and backfat thickness. In addition, the total pork price per pig was not affected by RF. Although total feed intake (TFI) and total feed intake cost (TFC) were significantly lower in the RF pigs (p<0.001), the feed cost per 1 kg weight gain (FCG) was similar regardless of the treatments. In conclusion, the RF method may decrease the feed cost due to a lower TFI and TFC.

• Tunnel and Underground Space
• /
• v.18 no.1
• /
• pp.44-57
• /
• 2008

In this study, a 2D finite-element analysis, using the SEEP/W program, was carried out to estimate the amount of groundwater flawing into a tunnel, as well as the groundwater tables around wetland areas during and after a tunnel excavation through rock mass. Four sites along the Wonhyo-tunnel in Cheonseong Mountain (Gyeongnam, Korea) were analysed, where the model damain of the tunnel included both wetland and fault zone. The anisotropy of the hydraulic conductivities of the rock mass was calculated using the DFN model, and then used as an input parameter for the cantinuum model. Parametric study on the influencing factors was perofrmed to minimize uncertainties in the hydraulic properties. Moreover, the volumetric water content and hydraulic conductivity functions were applied ta the model to reflect the ability of a medium ta store and transport water under both saturated and unsaturated conditions. The conductivity of fault zone was assumed ta be $10^{-5}m/sec\;or\;10^{-6}m/sec$ and the conductivity of grouting zone was assumed as 1/10, 1/50 or 1/100 of the conductivity of rock mass. Totally $6{\sim}8$ cases of transient flow simulation were peformed at each site. The hydraulic conductivities of fault zone showed a significant influence on groundwater inflow when the fault zone crossed the tunnel. Also, groundwater table around wetland maintained in case that the hydraulic conductivity of grouting zone was reduced ta be less than 1/50 of the hydraulic conductivity of rock mass.