• Proceedings of the Korean Information Science Society Conference
• /
• 2002.04a
• /
• pp.466-468
• /
• 2002

본 논문에서는 가상의 HLR agent database를 이용해서 다양한 CM을 가지는 단말들에 대해 적용할 수 있는 위치관리 기법을 제안한다. 기존에 제안된 방법들은 단말의 CMR을 특정범위로 제한하고 있다. 표적으로 AS(Anchor Strategy)는 CMR이 낮을 경우 위치등록 용을, caching은 CMR이 높을 경우 호 설정 비용을 줄이는 기법이다. 그러나 현실적으로는 단말의 이동과 호 수신 패턴은 일정치 않다. 기존 기법과 본 논문에서 제안하는 기법간에 성능평가를 위해 다양한 CMR을 가지는 단말들에 대한 시뮬레이션을 수행한 결과, 제안기법은 데이터베이스 접근비용이 다소 증가하지만 전체적으로 15%~20%의 성능향상을 가져올 수 있었다.

• Journal of the Korean Magnetics Society
• /
• v.8 no.3
• /
• pp.111-117
• /
• 1998

Recent discovery of colossal magnetoresistance (CMR) phenomena in perovskite manganese oxides has evoked great interest for its physical peculiarity and the possible industrial application. Besides manganese oxides, CMR phenomena is also observed in $Tl_2Mn_2O_7$ with pyrochlore structure and in Cr-based chalcogenide with spinel structure. In this paper, we have studied electronic structures of Cr-based chalcogenide spindles $Fe_{1-x}Cu_xCr_2S_4$ at x=0.0, 0.5, 1.0 using the linearized muffin-tin orbital (LMTO) band method within the local density approximation (LDA). The characteristic resistivity for x=0.0, 0.5 could be explained qualitatively in terms of the half-metalic electronic structure and the Jahn-Teller effect. Especially, the half-metallic nature appearing in the metallic temperature regime is well descibed by the proposed conduction model for x=0.0, 0.5, 1.0. We have suggested, based on the conduction model, that the CMR phenomena observed in these compounds are closely correlated with the obtained half-metallic electronic structure.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2003.12a
• /
• pp.343-343
• /
• 2003

• Korean Journal of Poultry Science
• /
• v.26 no.3
• /
• pp.195-201
• /
• 1999

The present study was conducted to investigate the effects of dietary supplemental dry powder of chinese medicine refuse (CMR) on the growth performance and physiological status of broiler chicks. The treatments consisted of corn-soybean meal control diet, CMR 4 and 8% diets. A total of 120 Arbor Acre broiler chicks were randomly allotted to 12 pens ; four pens per treatment and 10 birds per pen. The body weight gain and feed intake did not show ant differences among the treatment groups, but feed conversion was significantly higher (P〈0.05) in CMR 8% group than that of the control group. Hunt L and b did not show ant differences among the treatment groups, but hunt a was darker (P〈0.05) in CMR 4 and 8% group than that of the control group. The blood concentrations of total protein, sugar, glutamic-oxaloacetic-transaminase (GOT), glutamic-pyruvic-transaminase (GPT) Hemogloben were not different among the treatment groups. The pH of thigh muscle were lower in CMR 4 and 8% groups than that of the control group, but crude fat, crude ash of thigh muscle and bone hardness in brolier chicks did not show ant differences among the treatment groups. The saturated fatty acid content of the thigh muscle tende to decrease dietary CMR increased.

• Environmental Engineering Research
• /
• v.24 no.1
• /
• pp.107-116
• /
• 2019

Nitrogen removal, nitrous oxide ($N_2O$) emission and microbial community in sequencing batch and continuous-flow intermittent aeration processes were investigated. Two sequencing batch reactors (SBRs) and two continuous-flow multiple anoxic and aerobic reactors (CMRs) were operated under high dissolved oxygen (DO) (SBR-H and CMR-H) and low DO (SBR-L and CMR-L) concentrations, respectively. Nitrogen removal was enhanced under CMR and low DO conditions (CMR-L). The highest total inorganic nitrogen removal efficiency of 91.5% was achieved. Higher nitrifying and denitrifying activities in SBRs were observed. CMRs possessed higher $N_2O$ emission factors during nitrification in the presence of organics, with the highest $N_2O$ emission factor of 60.7% in CMR-L. SBR and low DO conditions promoted $N_2O$ emission during denitrification. CMR systems had higher microbial diversity. Candidatus Accumulibacter, Nitrosomonadaceae and putative denitrifiers ($N_2O$ reducers and producers) were responsible for $N_2O$ emission.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.566-572
• /
• 2009

Turn-key and CMF(CM for Fee) have been selected as procurement paths of large public projects in Korea. However, recently, researches and discussions on CMR(CM at Risk) have been popular as the Korean government seeks for alternative procurement paths to enhance the performance. In the CMR projects, the part who is responsible for construction management should predict and control the potential risks for guaranteeing benefits. In this paper, CMR projects in which a general contractor plays the role as CMr is mainly analyzed. We give attentions to risk management during construction process given that subcontractors, main parts in this phase, work in various ways and thus more chances for faults exist. In this case, for the general contractor, to recognize potential risks in previous to start construction works of subcontractor by means of virtual design and construction (VDC) must be essential to this end. The case study of practices on VDC in U.S in which CMR has been introduced can provide considerable aspects to implement it in Korea.

• Journal of the Korean Magnetics Society
• /
• v.15 no.2
• /
• pp.137-141
• /
• 2005

The CMR properties and magnetic properties of sulphospinels $Zn_xFe_{1-x}Cr_2S_4$ have been explored by X-ray diffraction, magnetoresistance measurement, and $M\ddot{o}ssbauer$ spectroscopy. The crystal structures in the range of x=0.05, 0.1, 0.2 are cubic at room temperature. Magnetoresistance measurement indicates that these system is semiconducting below about 160 K. The temperature of maximum magnetoresistance is almost consistent with Curie temperature. The Zn substitutions for Fe occur to increase the Jahn-Teller relaxation and the electric quadrupole shift. CMR properties could be explained with Jahn-Teller effect, and half-metallic electronic structure, which is different from both the double exchange interactions of manganite La-Ca-Mn-O system and the triple exchange interactions of chalcogenide $Cu_xFe_{1-x}Cr_2S_4$.

• Investigative Magnetic Resonance Imaging
• /
• v.23 no.4
• /
• pp.296-315
• /
• 2019

Cardiac magnetic resonance (CMR) imaging is widely used in many areas of cardiovascular disease assessment. This is a practical, standard CMR protocol for beginners that is designed to be easy to follow and implement. This protocol guideline is based on previously reported CMR guidelines and includes sequence terminology used by vendors, essential MR physics, imaging planes, field strength considerations, MRI-conditional devices, drugs for stress tests, various CMR modules, and disease/symptom-based protocols based on a survey of cardiologists and various appropriate-use criteria. It will be of considerable help in planning and implementing tests. In addressing CMR usage and creating this protocol guideline, we particularly tried to include useful tips to overcome various practical issues and improve CMR imaging. We hope that this document will continue to standardize and simplify a patient-based approach to clinical CMR and contribute to the promotion of public health.

• Journal of Cardiovascular Imaging
• /
• v.31 no.1
• /
• pp.26-38
• /
• 2023

BACKGROUND: Dobutamine and adenosine stress cardiac magnetic resonance (CMR) imaging is relatively contraindicated in patients with moderate to severe aortic valve stenosis (AS). We aimed to determine the safety of dobutamine and adenosine stress CMR in patients with moderate to severe AS. METHODS: In this retrospective study patients with AS who underwent either dobutamine or adenosine stress CMR for exclusion of obstructive coronary artery disease were enrolled. We recorded clinical data, CMR and echocardiography findings, and complications as well as minor symptoms. Patients with AS were compared to matched individuals without AS. RESULTS: A total of 187 patients with AS were identified and compared to age-, gender- and body mass index-matched 187 patients without AS. No severe complications were reported in the study nor the control group. The reported frequency of non-severe complications and minor symptoms were similar between the study and the control groups. Nineteen patients with AS experienced non-severe complications or minor symptoms during dobutamine stress CMR compared to eighteen patients without AS (p = 0.855). One patient with AS and two patients without AS undergoing adenosine stress CMR experienced minor symptoms (p = 0.562). Four examinations were aborted because of chest pain, paroxysmal atrial fibrillation and third-degree atrioventricular block. Inducible ischaemia, prior coronary artery bypass grafting, prior stroke and age were associated with a higher incidence of complications and minor symptoms. CONCLUSIONS: Moderate to severe AS was not associated with complications during CMR stress test. The incidence of non-severe complications and minor symptoms was greater with dobutamine.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2000.05a
• /
• pp.171-180
• /
• 2000