Serum 25-hydroxyvitamin D concentrations are associated with erythrocyte levels of <i>n</i>-3 PUFA but not risk of CVD

Park, Yongsoon,Kim, Minkyung Cambridge University Press 2011 The British journal of nutrition Vol.106 No.10

<P>Increasing evidence suggests that the status of vitamin D and <I>n</I>-3 PUFA is associated with the risk of CVD. Major dietary sources of vitamin D include fish and fish products, which are also rich in <I>n</I>-3 PUFA; however, the relationship between serum 25-hydroxyvitamin D levels and tissue contents of <I>n</I>-3 PUFA remains unknown. The present study investigates the hypothesis that serum 25-hydroxyvitamin D and erythrocyte <I>n</I>-3 PUFA levels are positively correlated in patients with CVD. We recruited sixty CVD cases and matched them with sixty healthy controls based on age, sex and season during which blood was drawn for the study. As serum 25-hydroxyvitamin D levels increased, erythrocyte levels of docosapentaenoic acid, DHA, omega-3 index and total <I>n</I>-3 PUFA increased significantly, while erythrocyte levels of stearic acid and total SFA decreased significantly, after adjusting for age, sex, BMI and smoking. Partial correlation analysis also showed that erythrocyte <I>n</I>-3 PUFA levels were positively correlated (<I>r</I> 0·215; <I>P</I> = 0·021) and total SFA content was negatively correlated (<I>r</I> − 0·263; <I>P</I> = 0·004) with serum 25-hydroxyvitamin D levels. However, multiple logistic regression analysis showed that serum 25-hydroxyvitamin D levels were not significantly associated with the risk of CVD, after adjusting or not adjusting for age, sex, BMI and smoking. In conclusion, the results of our case-control study suggest that serum 25-hydroxyvitamin D levels are positively related to erythrocyte <I>n</I>-3 PUFA levels, but are not associated with the risk of CVD in this population.</P>

Dietary Reference Intake of n-3 polyunsaturated fatty acids for Koreans

Yongsoon Park 한국영양학회 2022 Nutrition Research and Practice Vol.16 No.no.sup1

This paper examines the process and evidence used to create the Dietary Reference Intake (DRI) of alpha-linolenic acid (ALA) and eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) for Koreans. ALA (18:3n3) is an essential fatty acid, and EPA and DHA are known to have beneficial effects on cardiovascular disease risk and reduction of triglyceride levels. Various international organizations have suggested dietary recommendations for n-3 polyunsaturated fatty acids (PUFAs), including ALA, EPA, and DHA. A DRI for Koreans was established for the first time in 2020, specifically for the adequate intake (AI) of ALA and EPA + DHA. This recommendation was based on the average intake of ALA and EPA + DHA from the Korea National Health and Nutrition Examination Survey 2013-2017. For Korean infants, the AI of ALA and DHA was based on the fatty acid composition of maternal milk. Estimated average requirement and a tolerable upper intake level have not been set for n-3 PUFA due to insufficient evidence. In addition, the intake level of n-3 PUFA for prevention of chronic disease has also not been determined. Future studies and randomized controlled trials are required to establish the UL and to define the level for disease prevention.

Erythrocyte n–3 Polyunsaturated Fatty Acid and Seafood Intake Decrease the Risk of Depression: Case-Control Study in Korea

Park, Yongsoon,Kim, Malgeunsinae,Baek, Dawon,Kim, Seok-Hyeon Karger 2012 Annals of nutrition & metabolism Vol.61 No.1

<P>Abstract</P><P><B><I>Background/Aims:</I></B> Low intake or tissue levels of n–3 polyunsaturated fatty acids (PUFA) have been associated with an increased risk of depression, but some studies do not support the association. The purpose of the present study was to evaluate the hypothesis that erythrocyte levels of n–3 PUFA and intake of seafood are negatively associated with the risk of depression in Koreans. <B><I>Methods:</I></B> We investigated 80 patients diagnosed with a score ≥25 on the Center for Epidemiological Studies Depression Scale, Korean version, and confirmed by a psychiatrist. Eighty-eight controls without a chronic disease were matched to the cases for age and sex. <B><I>Results:</I></B> Multivariate-adjusted regression analysis showed that the risk of depression was significantly and negatively associated with erythrocyte levels of 20:5 n–3, 22:6 n–3, 16:0 and 18:0, but positively associated with erythrocyte levels of 18:2t and 16:1 after adjusting for confounding factors. In addition, the risk of depression was negatively associated with the intake of energy, carbohydrate, seafood and grains, but positively with the intake of fat and meat after adjustment for confounding factors. <B><I>Conclusions:</I></B> The risk of depression could be decreased with increased erythrocyte levels of n–3 PUFA and saturated fatty acids, as well as seafood intake, but decreased erythrocyte levels of trans fatty acids in Koreans.</P><P>Copyright © 2012 S. Karger AG, Basel</P>

A Study on Community Integration in Rural Tourism Development

Park, YongSoon(박용순),William P. Stewart(윌리엄 P. 스튜어트) 한국관광레저학회 2019 관광레저연구 Vol.31 No.4

Implementation Schemes to Compensate for Inverter Nonlinearity Based on Trapezoidal Voltage

Yongsoon Park,Seung-Ki Sul IEEE 2014 IEEE transactions on industry applications Vol.50 No.2

<P>Trapezoidal voltages can be used to compensate for the inverter nonlinearity. In particular, the modulating shape of these voltages facilitates the adaptation of the compensation to various operating conditions. In this paper, practical implementation schemes are proposed to improve the performance of the compensation method based on the trapezoidal voltage. After the implementation schemes are detailed, their effectiveness is discussed with experimental results. It has been proved that the proposed schemes are useful for the robust compensation.</P>

Intakes of vegetables and related nutrients such as vitamin B complex, potassium, and calcium, are negatively correlated with risk of stroke in Korea

Yongsoon Park 한국영양학회 2010 Nutrition Research and Practice Vol.4 No.4

Consumption of vegetables and fruits is associated with a reduced risk of stroke, but it is unclear whether their protective effects are due to antioxidant vitamins or folate and metabolically related B vitamins. The purpose of the study was to test the hypothesis that intake of fruits and vegetables, which are major sources of antioxidant and vitamin B complex vitamins, reduces the risk of stroke. Cases consisted of patients diagnosed with first event of stroke (n = 69). Controls (n = 69) were age-, sex-, and body mass index-matched to cases. Multivariable-adjusted regression analysis showed that subjects who ate four to six servings of vegetable per day had a 32% reduction in the risk of stroke, and those with more than six servings per day had a reduction of 69% after adjusting for age, sex, BMI, and family history of stroke. Intakes of total fat, plant fat, calcium, potassium, vitamin B1, vitamin B2, vitamin B6, niacin, and folate were significantly and negatively associated with the risk of stroke. Although the trend was not significant, stroke risk was reduced in the second quartile (1.21-2.66 servings per week) of fish intake. However, intake of fruits (average daily intake of 1.0 serving) and antioxidant vitamins such as carotene, vitamin C, and vitamin E was not associated with the risk of stroke. In conclusion, our observational study suggests that intake of fat and vegetables, rich sources of vitamin B complex, calcium, and potassium may protect against stroke.

A Novel Method to Compensate Non-Linearity of Inverter in Sensorless Operation of PMSM

Yongsoon Park,Seung-Ki Sul 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

The non-linearity of an inverter can be modeled as the distorted voltages. A novel method utilizing the trapezoidal voltages is proposed to cancel out the distorted voltages by the non-linearity. By modulating the shape of the trapezoid, the harmonic distortions in the output currents and the voltage references can be reduced. An integral controller is employed to modulate the trapezoid with simple signal processing. To evaluate the effectiveness of the propose method, the conventional methods are compared through the experimental results.

Analysis of Estimation Errors in Rotor Position for a Sensorless Control System Using a PMSM

Yongsoon Park,Seung-Ki Sul,Jun-Keun Ji,Young-Jae Park 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.5

In a sensorless control system with a Permanent Magnet Synchronous Motor (PMSM), the angular position of the rotor flux can be estimated by a voltage equation. However, the estimated angle may be inaccurate due to various causes. In this paper, it was comprehensively analyzed how various causes affect the angle error. As a result of the analysis, an error equation intuitively describing these relationships was derived. The parameter errors of a PMSM and the non-ideal properties of the driving system were identified as error-causing factors. To demonstrate the validity of the error equation, PMSMs were tested at various operating points. The variations in angle errors could be well explained with the error equation.

A Resiliency Coordinator Against Malicious Attacks for Cyber-Physical Systems

Yongsoon Eun,Jaegeun Park,Yechan Jeong,Daehoon Kim,Kyung-Joon Park 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

Resiliency of cyber-physical systems (CPSs) against malicious attacks has been a topic of active research in the past decade due to widely recognized importance. Resilient CPS is capable of tolerating some attacks, operating at a reduced capacity with core functions maintained, and failing gracefully to avoid any catastrophic consequences. Existing work includes an architecture for hierarchical control systems, which is a subset of CPS with wide applicability, that is tailored for resiliency. Namely, the architecture consists of local, network and supervision layers and features such as simplex structure, resource isolation by hypervisors, redundant sensors/actuators, and software defined network capabilities. Existing work also includes methods of ensuring a level of resiliency at each one of the layers, respectively. However, for a holistic system level resiliency, individual methods at each layers must be coordinated in their deployment because all three layers interact for the operation of CPS. For this purpose, a resiliency coordinator for CPS is proposed in this work. The resiliency coordinator is the interconnection of central resiliency coordinator in the supervision layer, network resiliency coordinator in the network layer, and finally, local resiliency coordinators in multiple physical systems that compose the physical layer. We show, by examples, the operation of the resiliency coordinator and illustrate that RC accomplishes a level of attack resiliency greater than the sum of resiliency at each one of the layers separately.

Multi-Level Operation with Two-Level Converters through a Double-Delta Source Connected Transformer

Park, Yongsoon,Ohn, Sungjae,Sul, Seung-Ki The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.6

This paper proposes a power conversion topology involving a multi-winding transformer and converters. The fundamental idea is described with circuit diagrams, and the voltage output of the proposed topology is analyzed mathematically. The effectiveness of the topology is discussed with test results from a small-scale power conversion system. When conventional hardware consisting of two-level converters and a transformer is employed, multi-level voltage outputs can be applied to the transformer windings by the proposed method.