• Title/Summary/Keyword: 방지방도

Search Result 184, Processing Time 0.026 seconds

The Medium Access Scheduling Scheme for Efficient Data Transmission in Wireless Body Area Network (WBAN 환경에서 효율적 데이터 전송을 위한 매체 접근 스케줄링 기법)

  • Jang, EunMee;Park, TaeShin;Kim, JinHyuk;Choi, SangBan
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.54 no.2
    • /
    • pp.16-27
    • /
    • 2017
  • IEEE 802.15.6 standard, a Wireless Body Area Network, aims to transfer not only medical data but also non-medical data, such as physical activity, streaming, multimedia game, living information, and entertainment. Services which transfer those data have very various data rates, intervals and frequencies of continuous access to a medium. Therefore, an efficient anti-collision operations and medium assigning operation have to be carried out when multiple nodes with different data rates are accessing shared medium. IEEE 802.15.6 standard for CSMA/CA medium access control method distributes access to the shared medium, transmits a control packet to avoid collision and checks status of the channel. This method is energy inefficient and causes overhead. These disadvantages conflict with the low power, low cost calculation requirement of wireless body area network, shall minimize such overhead for efficient wireless body area network operations. Therefore, in this paper, we propose a medium access scheduling scheme, which adjusts the time interval for accessing to the shared transmission medium according to the amount of data for generating respective sensor node, and a priority control algorithm, which temporarily adjusts the priority of the sensor node that causes transmission concession due to the data priority until next successful transmission to ensure fairness.

Porous Media Modelling and Verification of Thermal Analysis for Inlet and Outlet Ducts of Spent Fuel Storage Cask (사용후핵연료 저장용기 유로입출구의 다공성매질 모델링 및 열해석 검증평가)

  • Lee, Ju-Chan;Bang, Kyung-Sik;Choi, Woo-Seok;Seo, Ki-Seog;Ko, Sungho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.16 no.2
    • /
    • pp.223-232
    • /
    • 2018
  • Bird screen meshes are installed at the air inlet and outlet ducts of spent fuel storage casks to inhibit the intrusion of debris from the external environment. The presence of these screens introduces an additional resistance to air flow through the ducts. In this study, a porous media model was developed to simplify the bird screen meshes. CFD analyses were used to derive and verify the flow resistance factors for the porous media model. Thermal analyses were carried out for concrete storage cask using the porous media model. Thermal tests were performed for concrete casks with bird screen meshes. The measured temperatures were compared with the analysis results for the porous model. The analysis results agreed well with the test results. The analysis temperatures were slightly higher than the test temperatures. Therefore, the reliability and conservatism of the analysis results for the porous model have been verified.

Study for Sequential Application of Herbicide to Establish an Efficient Weed Control in Red Pepper Field (고추 밭 잡초 관리를 위한 제초제 체계 처리법 개발)

  • Min, Yi-Gi;So, Yoon-Sup
    • Weed & Turfgrass Science
    • /
    • v.5 no.4
    • /
    • pp.213-218
    • /
    • 2016
  • Timely application and the choice of herbicides are crucial for red pepper production since the yield is significantly reduced by weed occurrence. Experiments were conducted to provide efficient weed control methods in red-pepper fields. The results suggest the followings: 1) in the field of prevalent grass weeds, application of pendimethalin EC as pre-emergence herbicide after transplanting followed by tank-mix with pendimethalin and fluazipfop-P-butyl EC as post-emergence at 3-5 leaf stage of Digitalia species gave a good control for 80 days without crop injury, 2) as for grass and other weeds occurrence, sequential application of tank-mix with glufosinate-ammonium SL and pendimethalin at 30 days after transplanting (DAT) followed by glufosinate-ammonium. at < 20 cm of weed height with 30 days' interval provided better weed control than 2-time application of glufosinate-ammonium. single application for 80 days in this trial. 3) To prevent from drifting of non-selective herbicide spray mist into red-pepper at furrow application, glufosinate-ammonium. should be applied at 15 cm of spray nozzle height at 20 DAT (18 cm tall of red pepper), and the spray nozzle should be placed below 30 cm above ground to keep spray drift minimum to red pepper with > 40 cm plant height at 40 DAT.

The Effect of Antifat Diets with β-Cyclodextrin on the Weight Loss in Obese Korean Women (비만 여성에서 베타-사이클로덱스트린 함유 다이어트 식품의 체중 감소 효과)

  • 박병성
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.33 no.5
    • /
    • pp.832-838
    • /
    • 2004
  • This study investigated the effects of an antifat diet with $\beta$-cyclodextrin on the reduction of body weight, obesity index, body mass index, body fat mass, body circumferences and plasma lipid levels in obese Korean women. After maintaining an antifat diet for 45 days, there were significant reductions in body weight by 4 kg, obesity index by 5%, body mass index by 1 kg/$m^2$ and body fat mass by 7% as absolute values (p<0.05). When expressed as percentages of the decrease, these reductions remained significant at 4%, 13%, 4% and 20%, respectively (p<0.05). In addition, after maintaining this antifat diet for 45 days, there were also significant reductions in arm, waist, hip and thigh circumferences by 3 cm as absolute values when compared to before intake of antifat diet, and these reductions remained significant at 8%, 3.4%, 3% and 5%, respectively (p<0.05) as percentages of the decrease. Furthermore, this antifat diet significantly reduced triacylglyceride by 103 mg/dL, total cholesterol by 50 mg/dL and LDL-C by 50 mg/dL respectively (p<0.05). Thus, the present results demonstrate that $\beta$-cyclodextrin may have benefit as a novel food resource for diets to prevent obesity and control overweight in adult women.

The Clinical Characteristics of Elderly Suicide Attempters Visiting Emergency Room (응급실을 내원한 노인 자살시도자들의 임상적 특징)

  • Shin, Hyun Woo;Lee, Kang Joon;Kim, Hyun
    • Korean Journal of Psychosomatic Medicine
    • /
    • v.23 no.2
    • /
    • pp.100-106
    • /
    • 2015
  • Objectives : The purpose of this study was to find out the clinical and sociodemographic characteristics of elderly suicide attempters visiting emergency room, compared to non-elderly adult suicide attempters. Methods : We enrolled suicidal attempters who were treated in the emergency room of the Inje University Ilsan Paik Hospital between June 2013 and July 2015. We conducted a retrospective chart review of 336 suicidal attempters, and compared sociodemographic and clinical characteristics between elderly and non-elderly adult suicide attempters. Results : During the study period, 336 patients visited the emergency room of the medical center after suicide attempts. Among these, there were 71 elderly(21.2%) and 265 non-elderly adult(79.8%) suicide attempters. The suicidal methods among elderly were poisoning(73.3%), hanging(19.7%), cutting(5.6%), and jumping(1.4%). Those in non-elderly were poisoning(73.2%), cutting(17.0%), hanging(6.8%), and jumping(3.0%). The elderly suicide attempters had the tendency to choose more dangerous methods and showed higher lethality compared to adult suicide attempters(20.6% vs. 1.9%, ${\chi}^2=34.565$, p<0.05). On the other hand, premorbid psychiatric disorders had been more commonly diagnosed in non-elderly adults than elderly suicide attempters(49.8% vs. 26.8%, ${\chi}^2=12.024$, p<0.05). Conclusions : The results provide evidence of different sociodemographic and clinical characteristics of elderly suicide attempters compared to non-elderly ones visiting the emergency room. Through this study, it can be seen that the suicide attempt in the elderly tends to be severer than in the non-elderly, but only a small portion of them seek for help from psychiatric intervention. Further study is required to provide effective suicide prevention programs for elderly population.

Predictive model and quantitative microbial risk assessment of enterohemorrhagic Escherichia coli and Campylobacter jejuni in milk (우유에서 장출혈성 대장균과 캠필로박터균의 행동예측 모델 개발 및 정량적 미생물 위해성 평가 연구)

  • Dong, Jiaming;Min, Kyung Jin;Seo, Kun Ho;Yoon, Ki Sun
    • Korean Journal of Food Science and Technology
    • /
    • v.53 no.5
    • /
    • pp.657-668
    • /
    • 2021
  • We prepared the growth and survival models of enterohemorrhagic Escherichia coli (EHEC) and Campylobacter jejuni in milk as a function of temperature and assessed the microbiological risks associated with the consumption of whole milk. EHEC and C. jejuni were not detected in whole milk (n=195) in the retail market. The minimum growth temperature of EHEC in milk was 7℃. The lag time of EHEC in whole milk was longer than that in skim milk. The survival ability of C. jejuni in milk was better at 4℃ than at 10℃. Lower delta values were observed in whole milk than in skim milk, indicating that C. jejuni survived better in skim milk. The probability of foodborne illness from whole milk consumption was 5.70×10-5 for EHEC and 9.86×10-9 for C. jejuni. Sensitivity analysis results show that the market temperature of EHEC and the dose-response model of C. jejuni are correlated with the probability of foodborne illness.

Derivation of a 3D Arching Formula for Tunnel Excavation in Anisotropic Ground Conditions and Examination of Its Effects (비등방 지반에서 터널굴착을 위한 3차원 아칭식의 유도 및 그 영향 조사)

  • Son, Moorak
    • Journal of the Korean Geotechnical Society
    • /
    • v.34 no.12
    • /
    • pp.19-27
    • /
    • 2018
  • Terzaghi proposed a 2D formula for arching based on the assumption of a vertical sliding surface induced in the upper part due to the downward movement of a trapdoor. The formula was later expanded to consider 3D tunnel excavation conditions under inclined sliding surfaces. This study further extends the expanded formula to consider the effects of different ground properties and inclined sliding conditions in the transverse and longitudinal directions considering anisotropic ground conditions, as well as 3D tunnel excavation conditions. The 3D formula proposed in this study was examined of the induced vertical stress under various conditions (ground property, inclined sliding surface, excavation condition, surcharge pressure, earth pressure coefficient) and compared with the 2D Terzaghi formula. The examination indicated that the induced vertical stress increased as the excavation width and length increased, the inclination angle increased, the cohesion and friction angle decreased, the earth pressure coefficient decreased, and the surcharge pressure increased. Under the conditions examined, the stress was more affected at low excavation lengths and by the ground properties in the transverse direction. In addition, The comparison with the 2D Terzaghi formula showed that the induced vertical stress was lower and the difference was highly affected by the ground properties, inclined sliding conditions, and 3D tunnel excavation conditions. The proposed 3D arching formula could help to provide better understanding of complex arching phenomena in tunnel construction.

Grain Aging and Sensory Changes influenced by Milling and Packaging in Rice Storage (저장미 도정과 포장에 따른 고미화 및 식미 변화)

  • Lee, Ho-Jin;Kim, Tae-Hoon;Jeon, Woo-Bang
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.36 no.3
    • /
    • pp.266-270
    • /
    • 1991
  • Storage in the form of brown or milled rice saves space and cut cost rather than storage of rough rice, the common way of grain storage in Korea. But, brown or milled rice may be more susceptable to grain aging and sensory change than rough rice. Rice stored in government warehouse for 20 months after harvest was hulled into brown or milled rice and packaged with kraft paper bag (paper package), polyprophylen (PP package), and polyethylene (PE package). Then, after those rice packages were stored under room condition for one year, we investigated germinability, fat acidity, and sensory change to determine milling and packaging effects. Germinability of rough and brown rice was decreased significantly after long-term storge. In germination rate, Chucheong cultivar was lower than Milyang #23, brown rice was lower than rough rice, but there was no differences within packaging materials. TTC test which had a significant correlation with germinability can be used as a handy procedure for predicting grain germination. Fat acidity was increased as the order of rough < milled < brown rice in terms of milling, and PP < paper < PE package in terms of packaging materials. Especially, storage of brown rice increased fat acidity above 30 mg KOH, indicating one of characteristics of grain aging. To prevent from high fat acidity it was necessary to store in forms of rough grain with paper or PP packaging and milled rice with paper, or PP, or PE packaging. In sensory test of stored grain, eating quality in brown rice was the worst because of acidification of fatty acid. Also, eating quality of stored grain became worse as fat acidity increased.

  • PDF

Medvedev Administration's New Foreign Policy Line (메드베데프 정부의 새로운 대외정책노선 : 정책기조, 변화의 원인, 수행과정 분석을 중심으로)

  • Jeh, Sung-Hoon
    • Journal of International Area Studies (JIAS)
    • /
    • v.15 no.1
    • /
    • pp.31-60
    • /
    • 2011
  • Medvedev administration has adopted new foreign policy line because of Obama administration's 'Reset' policy and Global economic crisis. The objectives of Medvedev's new foreign policy are the creation of a favorable external environment and the efficient use of external resources for Russia's economic modernization. To achieve these goals, Medvedev's government fleshed out such specific action plans as the avoidance of conflicts with other powers, the prevention of conflicts around Russia's borders, the activation of capital investment, and the introduction of advanced technology from the outside. This foreign policy line takes shape in the building of a foundation for strategic cooperation with the United States, the preparation for 'Modernization Alliance' with Europe, the management of cooperation and conflict with China and Japan, and the introduction of a dual strategy of strategic stability and economic integration in relations with post-soviet states. In Russia's new foreign policy line the strengthening of relations with the United States and Europe acquires highest priority. However, this does not mean a return to a 'pro-Western liberal line' in the early 1990s. The ultimate goal of Russia's 'modernization' program still lies in the rebuilding of a powerful Russia in accordance with the multipolar world order that was Putin administration's foreign policy line. In this context, foreign policy change under Medvedev administration could be defined as a 'program change at international level' that signifies a change in the means to achieve goals without changing them.

A PHOTOELASTIC STUDY ON THE STRESS DISTRIBUTION OF THE UPPER ANTERIOR TEETH WHEN RETRACT WITH HIGH PULL J-HOOK HEADGEAR (상악전치의 후방견인시 J-hook headgear의 사용이 응력분포변화에 미치는 영향에 대한 광탄성학적 연구)

  • Lee, You-Jin;Park, Soo-Byung
    • The korean journal of orthodontics
    • /
    • v.27 no.5 s.64
    • /
    • pp.697-709
    • /
    • 1997
  • This study was designed to investigate the stress intensity and distribution produced by 1mm activation of retraction archwire with $0^{\circ},\;7^{\circ},\;14^{\circ}$ torque and application of high polk J-hook headgear during retraction of four maxillary incisors using the photoelastic stress analysis. The photoelastic model was made with a PL-3 type epoxy resin which was substituted by alveolar bone portion. Each retraction archwire was fabricated from .020' X .025' stainless steel wire which had vertical loops in 7mm height and hooks for high pull J-hook headgear between central and lateral incisors. The high pull J-hook headgear was applied 35 degree backward and upward to occlusal plane with 200gm pet each side The findings of this study were as follows: 1. In case of $0^{\circ}$ torque, the stress was distributed from cervical 1/8 to apex of roots of central and lateral incisors which were the forms of arc mode. When the high pull J-hook headgear was applied, the stress distributed by arc mode was presented from cervical 1/2 to apex of roots of central and lateral incisors. And the stress distributed by following the root surface was presented from alveolar crest to cervical 1/2 of roots of central and lateral incisors. The stress between apecies of central and Lateral incisors was presented also. 2. In case of $7^{\circ}$ torque, the stress distributed by arc mode was presented from cervical 1/2 to apex of roots of central and lateral incisors. And the stress distributed by following the root surface was presented from alveolar crest to cervical 1/2 of roots of central and lateral incisors. When the high pull J-hook headgear was applied, the stress distributed by following the root surface was presented mote apically than without headgear. The stress between apecies of central and lateral incisors was presented also. 3. In case of $14^{\circ}$ torque, the stress distributed by following the root surface was Presented from alveolar crest to apex of roots of central and lateral incisors. When the high pull J-hook headgear was applied, the stress distributed by following the root surface was presented stronger than without headgear The stress between apecies of central and lateral incisors was presented also.

  • PDF