• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.146-170
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• 2017

Joint channel assignment and routing is a well-known problem in multi-radio wireless mesh networks for which optimal configurations is required to optimize the overall throughput and fairness. However, other objectives need to be considered in order to provide a high quality service to network users when it deployed with high traffic dynamic. In this paper, we propose a re-configuration optimization model that optimizes the network throughput in addition to reducing the disruption to the mesh clients' traffic due to the re-configuration process. In this multi-objective optimization model, four objective functions are proposed to be minimized namely maximum link-channel utilization, network average contention, channel re-assignment cost, and re-routing cost. The latter two objectives focus on reducing the re-configuration overhead. This is to reduce the amount of disrupted traffic due to the channel switching and path re-routing resulted from applying the new configuration. In order to adapt to traffic dynamics in the network which might be caused by many factors i.e. users' mobility, a centralized heuristic re-configuration algorithm called State-Aware Joint Routing and Channel Assignment (SA-JRCA) is proposed in this research based on our re-configuration model. The proposed algorithm re-assigns channels to radios and re-configures flows' routes with aim of achieving a tradeoff between maximizing the network throughput and minimizing the re-configuration overhead. The ns-2 simulator is used as simulation tool and various metrics are evaluated. These metrics include channel-link utilization, channel re-assignment cost, re-routing cost, throughput, and delay. Simulation results show the good performance of SA-JRCA in term of packet delivery ratio, aggregated throughput and re-configuration overhead. It also shows higher stability to the traffic variation in comparison with other compared algorithms which suffer from performance degradation when high traffic dynamics is applied.

• 동의생리병리학회지
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• 제28권6호
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• pp.630-635
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• 2014

The purpose of this study was to investigate the effects of Naeso-san in interstitial cells of Cajal (ICCs) in murine small intestine. First, we isolated ICCs from murine small intestine. After that, we cultured these cells for 1 days. The patch-clamp technique was applied on ICCs that formed network-like structures in culture (1 days). Spontaneous rhythms were routinely recorded from cultured ICCs under current-clamp conditions, and the ICCs within networks displayed more robust electrical rhythms (pacemaker potentials). To understand the relationship between Naeso-san and pacemaker activity in ICCs, we examined the effects of Naeso-san on pacemaker potentials of ICCs. In current clamp mode (I = 0), the addition of Naeso-san (10 mg/ml - 50 mg/ml) decreased the amplitude and frequency of the pacemaker potentials of ICCs in a dose dependent manner. However, these effects were blocked by intracellular $GDP{\beta}S$, a G-protein inhibitor, and glibenclamide, a specific ATP-sensitive K+ channels blocker. Pretreatment with SQ-22536, an adenylate cyclase inhibitor, did not block the Naeso-san induced effects, whereas pretreatment with ODQ, a guanylate cyclase inhibitor, or L-NAME, an inhibitor of nitric oxide (NO) synthase blocked the Naeso-san induced effects. Our findings provide insight into unraveling the modulation of Naeso-san in pacemaker potentials of ICCs and developing therapeutic agents against gastrointestinal motility disorders.

• 멤브레인
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• 제30권3호
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• pp.181-189
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• 2020

본 연구에서는 생체모방형 비대칭 분리막 제조방법인 사각펄스양극산화법의 비대칭성 한계를 극복하기 위해 최근 보고된 셀렌산 전해액을 이용하고 표면개질에 따른 정류특성을 평가하였다. 분리막의 비대칭 원뿔형 채널은 최소직경이 10 nm이고 최대직경이 50 nm이며 길이가 5 ㎛이었다. 분리막의 정류특성은 기존 황산 전해액에서 제작된 것보다 높았으며 +1V에서의 전류가 -1 V일 때보다 최대 2.9배를 나타내었다. 또한, 실란화 반응을 이용한 표면개질을 통해 술폰산기를 도입한 분리막은 반대로 -1 V에서의 전류가 +1 V일 때보다 전류의 최대 4.2배인 정류특성을 나타냈다. 실험에 대한 이론적 증명은 2D 모델에 수치해석 결과를 제시함으로써 뒷받침되었다. 본 연구의 결과는 서로 다른 정류방향을 갖는 두 종류의 이온 정류 분리막을 손쉽게 제작할 수 있는 방법을 제시하며 이온의 이동을 제어하기 위한 다양한 연구 분야에 활용될 수 있을 것으로 기대된다.

• 대한디지털의료영상학회논문지
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• 제16권1호
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• pp.43-47
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• 2014

Sens of insecutity of the public and professionals about harmful effects of radiation is increasing in an accident at the Chernobyl and Fkushima nuclear power plant.Anxiety was amplified to lack of information about radiation majority of people. To target the middle and high school in the region of Daegu and Gyeongsangbuk-do, to investigate the radiation recognition of the next generation, it is intended to present a model of education for the safe use of radiation. The High School of the six metropolitan cities, city, town through the questionnaire and needs to be educational experience of radiation and use knowledge level of radiation, experience in daily life, understanding of man-made radiation and natural radiation, information channel on radiation, the radiation Distribute the total 800 parts of, to recover the 629 unit, was analyzed for 155 females 474 males. Many people 75.36% of the people, to 24.64% female subjects of this investigation, was constant, respectively from 13 to 18 years age. It is a large number and 30.37% of the respondents as "normal" level of knowledge of radiation, for the type of radiation, most knew. You have answer for risk experience of the medical radiation was higher, touching a lot of information via the broadcast medium in general, and the accuracy is low. I thought we wanted to be educated three or more twice a year, as an educator,about 71.37% and radiation-related understanding of knowledge and background in accordance with the diversification of information channels, the regional differences between urban and rural areas. But I considered the difference age (grade) for each is displayed, intended for junior high school students, the target surface and use the occurrence of radiation, high school students, the need for education about risk and application of radiation through this study.

• 동아시아식생활학회지
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• 제15권5
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• pp.516-523
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• 2005

This study was performed to investigate dietary behaviors and consumption of health food in cancer patients. The subjects were 163 cancer patients recruited from the general hospital in Seoul, Korea. The data were obtained by the structured self administered questionnaire. The mean age of subjects was 51 years. Most of subjects didn't eat the visual fat of meat and chicken skin. The mealtime of the subjects was generally regular and most of subjects had breakfast. The subjects of this survey liked to eat foods with sweet taste but disliked to eat hot, salty and sour taste ones. The preference for fish, marine products and vegetables was high but that for instant foods and frying foods was very low. Most of subjects consumed the foods that is generally known as anticancer foods such as vegetables and fruits. On the other hand, most of subjects didn't intake butter, margarine, and frying foods that is known as risk factors of cancer. The majority of subjects$(84.7\%)$ consumed the health food The main reasons for taking health foods by subjects were to cure disease$(58.0\%)$, to prevent disease$(45.3\%)$, to supply nutrients$(39.3\%)$, to maintain the mental state$(12.7\%)$ and to recover fatigue$(10.7\%)$. Majority of subjects$(66.0\%)$ spent money more than 200,000 won/month to buy health foods. The purchasing channels of health foods by subjects were recommendation by family or friend$(64.0\%)$, by physician/pharmacist$(18.0\%)$ and by nutritionist or dietician(6.0), and advertisement through TV or radio$(12.0\%)$. The types of taking health foods of the subjects were vegetable extracted food$(60.0\%)$, mushrooms$(51.3\%)$, Lactobacillus food$(25.3\%)$, enzyme food$(22.6\%)$ calcium containing food$(20.0\%)$ and so on. The results of the current study show that although many cancer patients already practice healthy dietary behaviors, there is a substantial proportion who do not and most of cancer patients consume health foods.' Further intervention is needed to explore the effect of health foods in cancer patients

• The Korean Journal of Physiology and Pharmacology
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• 제4권1호
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• pp.33-40
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• 2000

This study was designed to clarify the mechanism of the inhibitory action of a nitric oxide (NO) donor, 3-morpholino-sydnonimine (SIN-1), on contraction, cytosolic $Ca^{2+}$ level $([Ca^{2+}]_i)$ and ionic currents in guinea-pig ileum. SIN-1 $(0.01{\sim}100\;{\mu}M)$ inhibited 25 mM KCl- or histamine $(10\;{\mu}M)-induced$ contraction in a concentration-dependent manner. SIN-1 reduced both the 25 mM KCl- and the histamine-stimulated increases in muscle tension in parallel with decreased $[Ca^{2+}]_i.$ Using the patch clamp technique with a holding potential of -60 mV, SIN-1 $(10\;{\mu}M)$ decreased peak Ba currents $(I_{Ba})$ by $30.9{\pm}5.4%$ (n=6) when voltage was stepped from -60 mV to +10 mV and this effect was blocked by ODQ $(1\;{\mu}M),$ a soluble guanylyl cyclase inhibitor. Cu/Zn SOD (100 U/ml), the free radical scavenger, had little effect on basal $I_{Ba},$ and SIN-1 $(10\;{\mu}M)$ inhibited peak $I_{Ba}$ by $32.4{\pm}5.8%$ (n=5) in the presence of Cu/Zn SOD. In a cell clamped at a holding-potential of -40 mV, application of $10\;{\mu}M$ histamine induced an inward current. The histamine-induced inward current was markedly and reversibly inhibited by $10\;{\mu}M$ SIN-1, and this effect was abolished by ODQ $(1\;{\mu}M).$ In addition, SIN-1 markedly increased the depolarization-activated outward $K^+$ currents in the all potential ranges. We concluded that SIN-1 inhibits smooth muscle contraction mainly by decreasing $[Ca^{2+}]_i$ resulted from the inhibition of L-type $Ca^{2+}$ channels and the inhibition of nonselective cation currents and/or by the activation of $K^+$ currents via a cGMP-dependent pathway.

• 농촌계획
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• 제26권2호
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• pp.107-116
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• 2020

Up to date, the majority research on the major landscape elements in organic farming has been mainly focused on the practice of seeking efficiency. The problem is that this type of study contributes to polluting the agricultural environment and damaging the ecological circulation system. As an alternative, there is a growing body of research on organic farming, but it is not widely applied that research on how to manage the landscape considering the scenic characteristics of farming villages practicing organic farming. Therefore, this study was carried out in the conservative aspects of rural landscapes in order to effectively manage the landscape of organic agriculture and, intended to be used to maintain and preserve natural and ecologically harmonious landscapes by deriving management methods suitable for landscape elements targeting the major landscape elements of the organic farming complex. To carry out, this study performed the experts survey which is composed of 13 major landscape elements, including rice paddies and fields, monoculture and diverse crops, dirt roads, windbreak trees, accent planting, dum-bung(small pond), natural small river, natural waterways, plastic film houses, one-storied houses, and pavilion. As a result, Farm land was formed in a square shape, concentrated in an independent space, planted companion plants around the crop, and covered with plants to manage the borders. As for the surrounding environment, it was analyzed that the aspart road system circulating through the village, the evergreen broad-leaved windbreak forest around the cultivated land, and the accent plant located at the entrance of the village were suitable. The hydrological environment consists of Round small pond made of stone in an open space, natural rivers around the village, and natural channels around the farmland, and The Major facilities are suitable for greenhouses that are shielded by plants in independent regions, and wooden duck houses located inside the cultivation area are suitable and The settlement facilities were analyzed to be suitable for single-story brick houses located in independent residential areas, pavilion located with greenery in the center of the village, and educational spaces shielded with wood from arable land. If supplementary evaluation criteria suitable for the management of organic farming landscape are additionally supplemented based on the results derived from this study, It is expected to enhance the landscape value of ecologically superior organic farming.

• Molecules and Cells
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• 제43권1호
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• pp.66-75
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• 2020

Saturated fatty acids contribute to β-cell dysfunction in the onset of type 2 diabetes mellitus. Cellular responses to lipotoxicity include oxidative stress, endoplasmic reticulum (ER) stress, and blockage of autophagy. Palmitate induces ER Ca²⁺ depletion followed by notable store-operated Ca²⁺ entry. Subsequent elevation of cytosolic Ca²⁺ can activate undesirable signaling pathways culminating in cell death. Mitochondrial Ca²⁺ uniporter (MCU) is the major route for Ca²⁺ uptake into the matrix and couples metabolism with insulin secretion. However, it has been unclear whether mitochondrial Ca²⁺ uptake plays a protective role or contributes to lipotoxicity. Here, we observed palmitate upregulated MCU protein expression in a mouse clonal β-cell, MIN6, under normal glucose, but not high glucose medium. Palmitate elevated baseline cytosolic Ca²⁺ concentration ([Ca²⁺]_i) and reduced depolarization-triggered Ca²⁺ influx likely due to the inactivation of voltage-gated Ca²⁺ channels (VGCCs). Targeted reduction of MCU expression using RNA interference abolished mitochondrial superoxide production but exacerbated palmitate-induced [Ca²⁺]_i overload. Consequently, MCU knockdown aggravated blockage of autophagic degradation. In contrast, co-treatment with verapamil, a VGCC inhibitor, prevented palmitate-induced basal [Ca²⁺]_i elevation and defective [Ca²⁺]_i transients. Extracellular Ca²⁺ chelation as well as VGCC inhibitors effectively rescued autophagy defects and cytotoxicity. These observations suggest enhanced mitochondrial Ca²⁺ uptake via MCU upregulation is a mechanism by which pancreatic β-cells are able to alleviate cytosolic Ca²⁺ overload and its detrimental consequences.

• 생태와환경
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• 제47권spc호
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• pp.66-73
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• 2014

수달 서식지의 식생구조를 밝히고, 식생이 수달의 서식지 선택 요인 중의 하나인지를 구명하고자 연구하였다. 강원도 화천군의 북한강 본류와 지류 지천에서 수달흔적 발견지와 미발견지를 조사하였다. 수계의 식생형은 세 유형(단경초지형, 장경초지형, 관목지형)으로 구분되었다. 단경초지는 연수위변동이 큰 파로호와 북한강 상류에 분포하며, 명아자여뀌 (Persicaria nodosa), 하늘지기 (Fimbristylis dichotoma), 좀명아주 (Chenopodium ficifolium) 같은 일년생식물이 매우 우점한다. 관목지는 지촌천의 하류와 파로호 하부의 북한강 본류에 분포하며, 버드나무 (Salix koreensis)가 절대 우점하였다. 장경초지는 지류 하천에서 흔하며 거의 달뿌리풀 (Phragmites japonica) 순군락이다. 세 유형의 식생에서 수달의 흔적은 모두 발견되었으나 수달 미발견지는 모두 장경초지이었으며, 수달 발견지와 미발견지 간에 장경초지 식생의 상관이나 종조성은 유사하였다. 그러므로 수달이 서식지 선택 시 특정한 식생형을 선호한다고 보기는 어렵다. 다만, 수달 흔적이 발견되지 않은 장경초지는 지류의 상류로써 어류풍부도가 낮은 점이 공통적이다. 수달의 서식지 선택에 먹이인 어류의 풍부성이 가장 주요한 요인인 것으로 판단된다. 어류 풍부도가 높고 사람의 영향이 적은 평화의 댐 지역이 화천군의 수달분포에 최적지인 것으로 보인다.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.481-504
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• 2010

Wireless smart sensor networks (WSSNs) have been proposed by a number of researchers to evaluate the current condition of civil infrastructure, offering improved understanding of dynamic response through dense instrumentation. As focus moves from laboratory testing to full-scale implementation, the need for multi-hop communication to address issues associated with the large size of civil infrastructure and their limited radio power has become apparent. Multi-hop communication protocols allow sensors to cooperate to reliably deliver data between nodes outside of direct communication range. However, application specific requirements, such as high sampling rates, vast amounts of data to be collected, precise internodal synchronization, and reliable communication, are quite challenging to achieve with generic multi-hop communication protocols. This paper proposes two complementary reliable multi-hop communication solutions for monitoring of civil infrastructure. In the first approach, termed herein General Purpose Multi-hop (GPMH), the wide variety of communication patterns involved in structural health monitoring, particularly in decentralized implementations, are acknowledged to develop a flexible and adaptable any-to-any communication protocol. In the second approach, termed herein Single-Sink Multi-hop (SSMH), an efficient many-to-one protocol utilizing all available RF channels is designed to minimize the time required to collect the large amounts of data generated by dense arrays of sensor nodes. Both protocols adopt the Ad-hoc On-demand Distance Vector (AODV) routing protocol, which provides any-to-any routing and multi-cast capability, and supports a broad range of communication patterns. The proposed implementations refine the routing metric by considering the stability of links, exclude functionality unnecessary in mostly-static WSSNs, and integrate a reliable communication layer with the AODV protocol. These customizations have resulted in robust realizations of multi-hop reliable communication that meet the demands of structural health monitoring.