Nonlinear System Identification of a Refrigeration System

Tarcísio Soares Siqueira Dantas,Ivan Carlos Franco,Ana Maria Frattini Fileti,Fl avio Vasconcelos da Silva 대한설비공학회 2016 International Journal Of Air-Conditioning and Refr Vol.24 No.4

Applications of advanced control algorithms are important in the refrigeration field to achieve low-energy costs and accurate set-point tracking. However, the designing and tuning of control systems depend on dynamic mathematical models. Approaches like analytical modeling can be time-consuming because they usually lead to a large number of differential equations with unknown parameters. In this work, the application of system identification with the fast recursive orthogonal least square (FROLS) algorithm is proposed as an alternative to analytical modeling to develop a process dynamic model. The evaporating temperature (EVT), condensing temperature (CDT) and useful superheat (USH) are the outputs of interest for this system; covariance analysis of the candidate inputs shows that the model should be single-input–single-output (SISO). Good simulation results are obtained with two different validation data, with average output errors of 0.0343 (EVT model), 0.0079 (CDT model) and 0.1578 (USH model) for one of the datasets, showing that this algorithm is a valid alternative for modeling refrigeration systems

Poster Session : PS 0767 ; Rheumatology ; Arthritis in Older Man: Don`t Forget Paraneoplastic Syndromes

( Helena Martins ),( Tomas Abrantes Da Fonseca ),( Teresa Sequeira ),( Isabel Almeida ),( Antonio Marinho ),( Carlos Vasconcelos ) 대한내과학회 2014 대한내과학회 추계학술발표논문집 Vol.2014 No.1

The association of rheumatic manifestations with cancer is now well established. There are various rheumatological diseases that can be manifested as paraneoplastic syndromes, i. e. precede or occur simultaneously with different types of tumors, without local evidence of malignancy and regress after effective treatment of the tumor. In fact, the recognition of rheumatic symptoms as the fi rst translation of malignancy is essential for early treatment of the underlying tumor. The authors present a case of a 66 year-old man with no history of relevant disease nor family history of psoriasisor rheumatic diseases, with initial manifestation of chronic oligoarticular frame of the knees with severe systemic infi ammatory component associated with B symptoms, which evolved into symmetric infiammatory polyarthritis and morning stiffness. Analytically, without anemia or lymphopenia, increased infiammatory parameters, hemosedimentation velocity and C-reactive protein; Negative immunological study, including RF and anti-CCP, interpreted as probable seronegative rheumatoid arthritis. Excluded tuberculosis. Initially treated with NSAIDs, corticosteroids and methotrexate (MTX) without much articular benefi t, subsequently conducted infi ltrations and began salazopyrin (SSZ), with some clinical improvement. Onset of oral ulcers, whose biopsy revealed epidermoid carcinoma. Tumor with lymph node metastasis, requiring dissection, radiotherapy and chemotherapy, with clear improvement of the arthritis afterwards. Assumed paraneoplastic arthritis. Disease currently in remission, sporadically medicated only with NSAIDs. The relationship between malignancy and rheumatic manifestations is not simple. It is often diffi cult to identify the underlying tumor if not thinking about it, since the rheumatic paraneoplastic syndromes mimic well the idiopathic situations. On the other hand, the exhaustive search for a neoplasm in the initial assessment of rheumatic diseases is not recommended unless it is a high risk patient. Additionally, paraneoplastic arthritis may have independent natural history of tumors, thus the diagnosis is always a challenge.

Poster Session : PS 0012 ; Immunology : Retroperitoneal Fibrosis Related to Periaortitis - When to Think of It?

( Helena Lobo Martns ),( Nadejda Potlog ),( Antonio Marinho ),( Isabel Almeida ),( Carlos Vasconcelos ) 대한내과학회 2014 대한내과학회 추계학술발표논문집 Vol.2014 No.1

Retroperitoneal fi brosis (RF) is a rare condition characterized by the presence of infl ammatory and fi brous retroperitoneal tissue that may be idiopathic or secondary to other causes. Idiopathic RF is part of the spectrum of chronic periaortitis, a condition characterized by infl ammation and fi brosis surrounding the aorta and iliac arteries. The pathogenesis of idiopathic retroperitoneal fi brosis is unclear. The authors report the case of a 66 year-old woman with RF diagnosis related to infrarenal infl ammatory aortitis in 2009, following the study of a hypochromic microcytic anemia and increased infl ammatory parameters, confi rmed by imaging. She has a history of stenosing ileal Crohn`s disease, underwent surgery in 2006, with recurrence of ileal disease two years ago, treated and currently stable. As other relevant pathological antecedents, she contacted patients with pulmonary tuberculosis. She starting anti-tuberculosis therapeutic in September 2009 for nine months, because she has positive Mantoux test. The patient began high-dose corticosteroids with clinical benefi t, however with reduction in dose to about 20mg/day clinical worsening was observed with marked increase in infl ammatory parameters. Azathioprine was added during a short period due to myelosuppression. Subsequently started methotrexate with good response at an early stage but with need to change to cyclosporine due to worsening of infl ammatory parameters. Although there was an initial response to this drug, a sustained analytical and clinical response could only be achieved through the introduction of anti-TNF-alpha (Infl iximab). It was systematically excluded neoplastic, infectious, autoimmune and other infl ammatory diseases. The authors argue the importance of knowing and diagnosing rare diseases such as retroperitoneal fi brosis. It presents insidiously, often making the diagnosis diffi cult, thus you need to think about these diseases for successful diagnose. We point out the importance of knowing the biological drugs as potential therapeutic weapons in these cases.

Poster Session : PS 0703 ; Rheumatology ; Remission of Sweet Syndrome Secondary to Rheumatoid Arthritis Treated with Etanercept

( Helena Lobo Martins ),( Tomas Abrantes Da Fonseca ),( Teresa Sequeira ),( Isabel Almeida ),( Antonio Marinho ),( Carlos Vasconcelos ) 대한내과학회 2014 대한내과학회 추계학술발표논문집 Vol.2014 No.1

Sweet`s syndrome (SS) is the most common acute neutrophilic dermatosis (ND), often idiopathic although it is associated with a wide range of diseases, especially neoplastic, infi ammatory and infectious. We report the case of SS occurring on a 43-year-old woman with a known seronegative rheumatoid arthritis (RA) since 20 year-old. After diagnosis, was treated by NSAIDs, methotrexate (MTX) and gold salts with complete remission. Medication was suspended. In 2002, develops disabling symmetric polyarthritis, unresponsive to corticosteroids, NSAIDs and sulfasalazine. MTX was avoided due to chronic cholestasis (autoantibodies to primary biliary cirrhosis were negative, IRM excluded primary sclerosing cholangitis and liver biopsy without cirrhosis or interface hepatitis). Initiated Anti-TNF alpha monotherapy (Adalimumab) in 2004 with complete remission. Suspended due to pregnancy in 2007 and stayed in remission without drugs until 2014. In 2012, she presented widespread painful mucocutaneous lesions involving the neck, trunk and upper limbs, with fever, arthralgia and deterioration of general condition, compatible with SS. Biopsy confi rmed diagnosis. Systematically excluded tuberculosis, lympho/myeloproliferative and other autoimmune diseases. Executed corticotherapy unsuccessfully, having developed iatrogenic diabetes. Improvement of lesions with dapsone, maintaining tolerable oral lesions. In 2014, worsening cutaneous lesions and initiates cyclosporine without any benefit. Under cyclosporine, progression to disabling oral lesions, and severe polyarthritis with DAS 28 5. 02 (high activity disease). The authors assumed SS secondary to RA and started anti-TNF alpha etanercept. Skin lesions improved within few days, with complete regression of all clinical and laboratory abnormalities. The authors argue the importance to consider SS in differential diagnosis of new mucocutaneus lesions in patients with known autoimmune diseases, including RA. The diagnosis should be based on clinical,laboratory and histological fi ndings of an acute febril neutrophilic dermatosis without vasculitis. In these cases, the treatment with anti-TNF alpha is an option.