• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2019.05a
• /
• pp.29-32
• /
• 2019

The development of Information and Communication Technology facilitates exchange of information and communication between system in ships or between ships and land facilities, thereby improving the efficiency of their work. However, these changes in the working environment of companies and ships increased the likelihood of cyber security incidents occurance like unauthorized access to company and ship systems or infection of malicious code, which results in significant safety, environmental and business damage to company and ships. Therefore, a cyber-risk-based approach was required to identify and respond to an increasing cyber threats. In this paper, the analysis of maritime cyber security status and guidelines for establishment of maritime cyber security system are provided.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.35 no.8
• /
• pp.131-138
• /
• 2019

Since concrete has a low tensile strength compared to the compressive strength, reinforced concrete flexural members represent easy crack occurance under a small load. In order to overcome this problem, steel fiber reinforced concrete has been developed to compensate the tensile strength and brittleness of members. However, in the design formula of the domestic building code, it is not specified in the design formula reflecting the material characteristics. Therefore, the field application of the steel fiber reinforced concrete have had many restrictions. In this study, a flexural tensile strength model of steel fiber reinforced concrete is proposed by collecting and analyzing the material properties of material test results conducted by various researchers, and verified by the test results of cracking and stiffness evaluation of flexural members based on the proposed model. As a result of this study, the flexural tensile strength model of steel fiber reinforced concrete which can reflect the mixing ratio and aspect ratio of the steel fiber was proposed and the validity of the proposed material model equation was evaluated from the load-deflection relationship in the flexural test of the slab member.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.1
• /
• pp.69-74
• /
• 2003

In this paper, we propose the synchronization recovery algorithm which is suitable to wireless Multimedia of wireless channel situation which is being used OFDM signaling method. The basic of the suggested clock synchronization. restoration Algorithm is to getting the shock response of channel or getting the multipath strength profile through IFTT after the getting the frequency, response of deducted channel from channel deducted of receiver and to trace the location in the channel energy concentrated area of timing area. And it also analysis the start point of 64-QAM and 16-QAM if the sampling clock offset has the sample of ${\pm}$ 1-3, and we identified the occurance of performance deterioration when occures more than 2 samples of offset to compare with star point and BER performance in optimum sampling point result of BER performance checking, and we know that the recovery algorithm proposed algorithm also provide excellent synchronization characteries under frequency, selecting fading channel as result of simulation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.14 no.2
• /
• pp.76-82
• /
• 1981

A water culture experiment was carried out to elucidate the relationship between the nutritional conditions emphasized on $SiO_2$ of rice plant with the growth stages and rice blast incidence. Two rice cultivars, Milyang 23 and Nakdongbyeo were tested under the two Nitrogen levels and $SiO_2$ applications at the different growth stages. The results obtained were as follows. 1. By silicate application, the incidence of rice blast disease was remarkably reduced possibly due to increase of silicate and decrease of nitrogen contents in rice plant. 2. Silicate application at the late growth stage also reduced infected ratio of neck blast. 3. The effect of silicate on reducing the incidence of rice blast disease was clearer in neck blast than in leaf blast.

• Korean Journal of Animal Reproduction
• /
• v.21 no.4
• /
• pp.411-421
• /
• 1997

A survey was carried out to investigate the symptoms and occurance of reproductive disorder in Hanwoo(Korean native cattle). Data of the reproductive disorder of 561 heads from 28 farm households have been collected from Dec. '95 to Nov. '96 and analyzed calving no, nutritional body condition and housing forms. The results obtained are summarized as follows: 1. The incidence of reproductive disorder was 20.1% and the major common symptoms were repeat breeding(39.8%), anestrous(31.0%), nymphomania(10.6%) and subestrous(8.9%). 2. The incidence of reproductive disorder according to the calving no., that of heifer, calved one to two calving no. and over three calving no. were 20.6%, 13.9% and 34.5%, respectively. 3. Reproductive disorder incidence according to the nutritional body condition was 18.3%, 14.6% and 48.7% at body condition score(BCS) less than 2.0, 2.5 to 3.0 and over than 3.5, respectively. At BCS over 3.0, the symptoms of common reproductive disorder were repeat breeding(17.6%), anestrous(12.2%), nymphomania(10.8%) and subestrous(2.7%). 4. The incidence of reproductive disorder according to the housing form 15.8% and 34.6% for group feeding in open house and individual stanchion feeding in stall, respectively. In group feeding, reproductive disorder incidence of cows raised in space of more than 9.9$m^2$ per head was 14.1%, while that of cows raised less than 9.9$m^2$ per head was 18.2%. And incidence of repeat breeding, aneestrous and subestrous was more frequent in individual stanchion feeding than group feeding.

• Journal of Periodontal and Implant Science
• /
• v.23 no.1
• /
• pp.127-134
• /
• 1993

The purpose of this study was to observe the control effect of hypersensitivity after periodontal treatment in the 19% microcrystalline hydroxyapatite containing toothpaste for the subject of 85 persons of both sexes, who complained hypersensitivity. At 2 weeks and 4 weeks after periodontal treatment, comparison of control effect was performed between the 19% microcrystalline hydroxyapatite containing toothpaste group and control group. The result were as follows, 1. The main causes of dentin hypersensitivity are the root exposure with gingival recession and cervical abrasion. 2. The occurance rate of hypersensitive tooth in the upper jaw was higher than that of the lower jaw, and more or less, the molar area showed more occlurance of hypersensitivity than the premolar and incisor area in both jaw. 3. Patients showed very sensitive response to the thermal stimulus, especially cold stimulus. 4. Exellent control effect of hypersensitivity in 19% microcrystalline hydroxyapatite containing toothpaste group showed 83.02% at 2weeks, 92.45% at 4weeks and these values were higher than the control group. In conclusion, we find that 19% microcrystalline hydroxyapatite containing toothpaste have the control effect of hypersensitivity and the proper toothbrushing method is the key in attaining more effectiveness of the toothpaste.

• Journal of Advanced Marine Engineering and Technology
• /
• v.15 no.4
• /
• pp.29-45
• /
• 1991

Lip type stern tube sealing systems have used in almost all the middle or large ships which are being constructed in these days. It seems that the pressure fluctuation of the seal ring interspace, the cross-section profile and the materials quality of the seal rings have great effects on the sealing fuction of this sealing system. In this paper, the mechanical movement of lip seal ring which plays the most important role in stern tube sealing system and the possibility of leakage caused by pressure fluctuation are studied by theory and experiment. Using the finite element method for the axi-symetric object which receives the torsional load, the displacement and stress analysis of the seal rings, and also the possibility of crack occurance is checked by theoretical analysis. If the force which seal ring lip periphery receives is too small, there will be the possibility of leakage caused by the pressure fluctuation of the seal ring interspace, and if this force is too large, the frictional force between the seal ring and the liner will become problematical. The possibility of leakage caused by hardening of seal ring materials and creep phenomena of tested seal rings are also examined. The trial seal rings were designed and manufactured using the program of displacement and stress analysis developed in this study and the experimental apparatus to test the trial seal rings was also designed and manufactured. This trial seal rings were fitted in the experimental apparatus which was made in the same form as an actual stern tube. The one side of this apparatus was filled with sea water and the other side of it was filled with the lubricating oil. The leakage of oil and sea water was checked and the temperature was measured, rotating the propeller shaft at the constant velocity by D.C. motor. It was proved that the trial seal rings made in Viton rubber functioned excellenty but the trial seal rings made in N.B.R. rubber had problem in its durability.

• The Korean Journal of Pain
• /
• v.11 no.1
• /
• pp.47-53
• /
• 1998

Background: Epidural coadministration of opioids and local anesthetics has provided excellent analgesia during postoperative period. However, it is usually associated with the occurance of many side effects which were induced by epidural morphine. Low dose of intravenous naloxone has been known to reduce morphine-induced side effects without reversing analgesia, but the effect of epidural naloxone has not been defined in human study. Therefore we evaluated side effects and analgesia when naloxone was administered via epidural route. Methods: Eighty patients having epiduro-general anesthesia for hysterectomy were randomly assigned to one of four study groups. As a mean of postoperative pain control, all received 2 mg of epidural morphine bolusly at 1 hr before the end of surgery and continuous epidural infusion was started by Two-day Infusor containing morphine 4 mg in 0.125% bupivacaine 100 ml with either none of naloxone(Group 1, n=20), 2 ug/kg/day of naloxone(Group 2, n=20), 3 ug/kg/day of naloxone(Group 3, n=20) or 4 ug/kg/day of naloxone(Group 4, n=20). Study endpoints included visual analog scales(VAS) for pain, severity of nausea, itching, somnolence and respiratory depression. They were assessed at 2, 4, 8, 16, 32, and 48 hr postoperatively. Results: VAS for pain showed significant difference in Group 4 compared with Group 1 at all of the evaluation time. Itching score decreased significantly in Group 3 and 4 after 8 hr postoperatively and nausea score decreased significantly in Group 3 after 4 hr postoperatively. Alertness score decreased significantly in Group 3 and 4 especially in early postoperative period. Conclusion: This study suggests that epidural naloxone reduce morphine-induced side effects in dose-dependent fashion without reversal of the analgesic effect of epidural morphine.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.5 no.2
• /
• pp.280-292
• /
• 1998

Pressure sores are a serious concerns in that respect to increasing risk of medical complications and medical costs. Prevention and care of pressure sores is an essential area of nursing practice. The nurse at ICU should be more careful of maintaining the skin integrity of patients especially than at any other place. This study was conducted to determine if the risk facotrs of pressure sores and nutritional status of the patients at risk for pressure sores is related the occurance of pressure sore. The risk group refers the patients having the below 14 scores of the braden scale. The 100 subjects were recruited from the ICU ward at an university hospital in Choongnam. The parameters for nutritional status are the blood chemistry including plasma protein, albumin, hemoglobin and the anthropometric measurements consisting of weight, BMI, LBM, the proportion of body fat, body fluid and triceps skin fold using bioimpedence analizer and caliper. The results are as follows : 1. The subjects were 55 years and stayed 8 days on average. Of the 100 subjects, males were 61%, neurologic/neurosurgical diseases were 68% and the incidence of pressure sores was 17% mainly occuring within 3days after the admission. 2. The present paralysis(or paraplegia) and edema(arm, leg, trunk) were showed more significantly the subjects with pressure sores than those without pressure sores. 3. Regarding with the nutritional status, the subjects with pressure sores had significantly lower the weight, BMI, LBM, body fluid, albumin than the ones without pressure sores. This results were supported the reports of previous studies that the decreased weight and albumin could be the important predictors of pressure sores. Thereafter we should encourage these factors to be utilized in predicting pressure sores for a comprehensive assessment. Nurse should identify patients at risk of the development of pressure sores, assess their nutritional status and dietary intake at regular intervals.

• Journal of Chest Surgery
• /
• v.26 no.2
• /
• pp.75-79
• /
• 1993

Myocardial protection against ischemic and reperfusion injuries is still in troublesome eventhough couples of the way of myocardial protection have been applied since 1970's. One of the possibility in myocardial protection is adding Fructose-l,6-diphosphate(FDP) in cardioplegic solution. It is assumed that FDP can promote ATP production under anaerobic condition as well as inhibiting the supressing effect of lactate on phosphofructokinase. We compared the myocardial protecting effects of FDP in crystalloid cardioplegic solution (St. Thomas formula, 10$^{\circ}C$, pH = 7.4) and reperfusate using isolated rat hearts in modified Langendorf apparatus by the parameters of preischemic and post reperfusing heart rate, time to first beat, occurance of arrhythmia, time to stabilization, and the rate of left ventricular pressure developing. Group A (n = 10), containing no FDP in cardioplegic and reperfusing solutions was control. Group B (n = 5), containing FDP in cardioplegic solution, showed statistically significant superiority of postischemic left ventricular pressure development than the control group. Group C (n = 5), containing FDP in reperfusate, showed statistically significant myocardial depressing effect than the controls. Other parameters were unremarkable. The cause is uncertain, but it is assumed that the negative feedback inhibition of FDP in energy metabolism or unknown blocking effect of FDP on certain transmembrane ionic currents is present. In conclusion, 1) FDP in cardioplegic solution has beneficial effect on postischemic left ventricular preservation. 2) FDP is strong acid when is hydrolyzed, so precise acid titration is neccessary. 3) FDP in reperfusate has negative left ventricular preservation, otherwise the mechanism is still uncertain.