• Journal of the Korea Society for Simulation
• /
• v.12 no.3
• /
• pp.31-40
• /
• 2003

This paper studies an optimal policy for a certain class of (s, S) inventory control systems, where the demands are characterized by the renewal arrival process. To minimize the average cost over a simulation period, we apply a stochastic optimization algorithm which uses the gradients of parameters, s and S. We obtain the gradients of objective function with respect to ordering amount S and reorder point s via a combined perturbation method. This method uses the infinitesimal perturbation analysis and the smoothed perturbation analysis alternatively according to occurrences of ordering event changes. The optimal estimates of s and S from our simulation results are quite accurate. We consider that this may be due to the estimated gradients of little noise from the regenerative system simulation, and their effect on search procedure when we apply the stochastic optimization algorithm. The directions for future study stemming from this research pertain to extension to the more general inventory system with regard to demand distribution, backlogging policy, lead time, and inter-arrival times of demands. Another direction involves the efficiency of stochastic optimization algorithm related to searching procedure for an improving point of (s, S).

• Journal of the Korea Safety Management & Science
• /
• v.4 no.1
• /
• pp.105-114
• /
• 2002

Nowadays, most companies seek after the greatest profit by means of offering the goods which consumers want timely and efficiently and minimizing the cost of inventory and distribution channel which amounts to the great portion of total cost. And according as EC(Electronic Commerce) market has increased rapidly, SCM(Supply Chain Management) for EC become one of the most important facts for companies, therefore this paper suggest SCM scheme which EC, especially B to C, is added to the existing commerce system. This paper uses internet for information integration of distribution channel which is away from one another and applies TOC(Theory of Constraint)'s DBR(Drum-Buffer-Rope) Scheduling for synchronization through the whole supply chain. It is possible to synchronize the whole supply chain by means of making the speed of manufacturing and distribution to be controlled by consumer's order which is received in distribution center, and inventory and loss of sales opportunities are minimized by constant. Buffer Management. If inventories in distribution center is short, then it needs to search CCR(Capacity Constraint Resource) in supply chain and to control the speed of manufacturing and distribution according to the ability of CCR. This paper applies PT(Partial Transshipment) strategy for Delivery from distribution center to store or cyber consumer. the strategy this paper suggests chooses neighbour area from area which each distribution center takes charge, and then makes product ordered by cyber consumer which lives in the chosen area to be delivered according to inventory of distribution center.

• The Journal of Korean Physical Therapy
• /
• v.28 no.6
• /
• pp.385-392
• /
• 2016

Purpose: This study aimed to evaluate the relationships among quality of life, caregiver depression levels, and disease severity, especially motor function, in children with cerebral palsy. Methods: Data were collected through questionnaires using survey and interview from 80 caregivers of children with cerebral palsy. The caregivers' quality of life was measured using medical outcomes study 36-item short form health survey, and level of depression was scored using the beck depression inventory. In addition, children's motor function was evaluated using gross motor function measure-88 and functional independence measure scores. Results: Among 8 domains of medical outcomes study 36-item short form health survey, "physical functioning," "physical role functioning," "mental health," and "bodily pain" domains were significantly correlated to "total" percentage scores of gross motor function measure-88. In addition, "mental health" and "bodily pain" domains were correlated to each sub-dimension, including "lying and rolling," "sitting," "crawling and kneeling," "standing," and "walking, running, and jumping." Similarly, the "running" and "jumping" dimensions including motor function measures correlated with "transfer," "locomotion," and "motor subtotal" of functional independence measure scores. The beck depression inventory scores were negatively correlated to "lying and rolling," "sitting," "crawling and kneeling," and the "total" percentage scores of gross motor function measure-88. The beck depression inventory scores were negatively correlated to "sphincter control," "communication," "social cognition," "cognitive subtotal," and "total" functional independence measure scores. Conclusion: It is necessary to consider the quality of life and emotional problems of caregivers of CP children and support them both physically and psychologically with comprehensive rehabilitation.

• Korean Journal of Psychosomatic Medicine
• /
• v.5 no.2
• /
• pp.158-167
• /
• 1997

Objectives: This study was aimed to investigate the emotional state and personality characteristics of alopecia aerata patient and to determine whether these characteristics are similar with those of neurotic patient. Methods : 20 alopecia aerata patients, 20 neurotic patients, and 20 normal healthy controls were studied. Beck Depression Inventory(BDI), State and Trait Anxiety Inventory(STAI) and Korean standardized edition of Catell's 16 Personality factors Questionnaire(16PF) were used for assessment. Results: 1) Total score of BDI was higher in neurosis group than alopecia aerata group and normal control group(p<0.05). Inspire of statistical non-significance, total score of in alopecia aerata group was higher than normal control group. 2) Total scores of state anxiety and trait anxiety in alopecia aerata and neurosis group were significantly higher than normal control group(p<0.001). 3) In first-stratum source traits of 16PF, normal control group was significantly higher than alopecia aerata group and neurosis group in B-factor(intelligence) and C-factor(ego-strength)(p<0.05). Alopecia aerata group and neurosis group were significantly higher than normal control group in O-factor(guilt-proneness) and $Q_4-factor(tension,\;anxiety)$(p<0.001). 4) In second-stratum source traits of 16PF, alopecia aerata group and neurosis group were significantly higher than normal control group in ANX-factor(anxiety)(p<0.05). Conclusions : These results suggest that emotional state and personality characterstics of patients with alopecia aerata are a distinguishable different to compare with normal control, and are very similar with those of neurotic patients. The authors propose that psychiatric management in patient with alopecia aerata will be more benificial.

• Journal of Korean Academy of Nursing
• /
• v.13 no.2
• /
• pp.70-86
• /
• 1983

The purpose of study carried out to determine the effect of informativeness influeucing the state-Anxiety of Hysterectomy patient, the relationship between Hysterectomy patient's general characteristics on State-Anxiety. and to investigation the cause of hysterectomy patient's Anxiety, the relationship between the cause of Anxiety and State-Anxiety. This stuad carried out between April 14. to May 24. 1983. This study sample consisted of 104 Hysterectomy patient who admitted to department of obstetrics of Seoul National University Hospital, Korea University Hospital, Han Yang University Hospital and Seung Nam Hospital. The Sample were divided into two groups; fifty two of experimental and fifty two of control group. The method used for the collection of data were set of information prepared by reseacher and state-Anxiety Inventory, The Questionnaire of state-Anxiety Inventory was made up 20 items. The data was analyzed by computer program. The results of the study were as follows. 1. There was shown state Anxiety to be alleviated by experimental group and control group. 2. There was significant relation between experimental group and control group. (p<0.01) 3. There was relation of state-Anxiety by education Level: Experimental group (p＜0.05) control group (p<0.05) religion : only control group (p＜0.05)economic state : only control group (p<0.05) The people who encouraged hysterectomy: Experimental group (p<0.05) control group (p＜0.0001) 4. The cause of preoperative anxiety about hysterectomy were as follows: 1) destruction of body image(=loss of uterus) 2) husband's attitude 3) Expactation that hysterectomy will adversely affect sexual relation 5. Among the cause of Anxiety, R²for state-Anxiety were as follows: 1) economic state 17.3% 2) deatch 21.6% 3) Expactation that hysterectomy will adversely affect sexual relation 24.5%.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.10
• /
• pp.867-873
• /
• 2001

The purpose of this study is to find analytic solution of determining the optimal capacity (lot-size) of multiproduct acyclic multistage production and inventory system to meet the finished product demand under the constraint of finite intermediate storage. Intermediate storage is a practical way to mitigate the material flow imbalance through the line of supply and demand chain. However, the cost of constructing and operating storage facilities is becoming substantial because of increasing land value, environmental and safety concern. Therefore, reasonable decision-making about the capacity of processes and storage units is an important subject for industries. The industrial solution for this subject is to use the classical economic lot sizing method, EOQ/EPQ(Economic Order Quantity/Economic Production Quantity) model, incorporated with practical experience. But EOQ/EPQ model is not suitable for the chemical plant design with highly interlinked processes and storage units because it is developed based on single product and single stage. This study overcomes the limitation of the classical lot sizing method. The superstructure of the plant consists of the network of serially and/or parallelly interlinked non-continuous processes and storage units. The processes transform a set of feedstock materials into another set of products with constant conversion factors. A novel production and inventory analysis method, PSW(Periodic Square Wave) model, is applied to describe the detail material flows among equipments. The objective function of this study is minimizing the total cost composed of setup and inventory holding cost. The advantage of PSW model comes from the fact that the model provides a set of simple analytic solutions in spite of realistic description of the material flows between processes and storage units. the resulting simple analytic solution can greatly enhance the proper and quick investment decision for the preliminary plant design problem confronted with economic situation.

• Journal of Institute of Control, Robotics and Systems
• /
• v.9 no.5
• /
• pp.407-412
• /
• 2003

An effective methodology is .reported for determining the optimal capacity (lot-size) of batch processing and storage networks which include material recycle or reprocessing streams. We assume that any given storage unit can store one material type which can be purchased from suppliers, be internally produced, internally consumed and/or sold to customers. We further assume that a storage unit is connected to all processing stages that use or produce the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. The objective for optimization is to minimize the total cost composed of raw material procurement, setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory hold-up. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two subproblems. The first yields analytical solutions for determining batch sizes while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks. For the special case in which the number of storage is equal to the number of process stages and raw materials storage units, a complete analytical solution for average flow rates can be derived. The analytical solution for the multistage, strictly sequential batch-storage network case can also be obtained via this approach. The principal contribution of this study is thus the generalization and the extension to non-sequential networks with recycle streams. An illustrative example is presented to demonstrate the results obtainable using this approach.

• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.6
• /
• pp.537-544
• /
• 2004

An effective methodology is reported for determining the optimal lot size of batch processing and storage networks which include uncertain demand forecasting. We assume that any given storage unit can store one material type which can be purchased from suppliers, internally produced, infernally consumed, transported to or from other sites and/or sold to customers. We further assume that a storage unit is connected to all processing and transportation stages that consume/produce or move the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. A batch transportation process can transfer one material or multiple materials at once between sites. The objective for optimization is to minimize the probability averaged total cost composed of raw material procurement, processing setup, transportation setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two sub-problems. The first yields analytical solutions for determining lot sires while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks for the given demand forecast scenario. The result of this study will contribute to the optimal design and operation of the global supply chain.

• Journal of Oriental Neuropsychiatry
• /
• v.31 no.3
• /
• pp.135-147
• /
• 2020

Objectives: Hwa-byung is a mental illness. It is also known as a Korean culture-related syndrome. In traditional Korean medicine, Sihogayonggolmoryeo-tang is used to treat Hwa-byung related neuropsychiatric symptoms. The purpose of this research was to examine the effect of Sihogayonggolmoryeo-tang on Hwa-byung. Methods: A multicenter, randomized, double-blinded, placebo-controlled study was performed for 160 patients with Hwa-byung. Patients were divided into a Sihogayonggolmoryeo-tang group and a placebo group. Treatment period was 8 weeks. Hamilton Rating Scale for Anxiety (HAM-A), Likert scale for major symptoms of Hwa-byung, Hwa-byung Scale (HBS), Korean Beck Depression Inventory (K-BDI), Korean State-Trait Anxiety Inventory (K-STAI), Korean State-Trait Anger Expression Inventory (K-STAXI), and Korean WHO Quality of Life Scale Abbreviated Version (WHOQOL-BREF) were used to evaluate the effect of Sihogayonggolmoryeo-tang on Hwa-byung. We also used an Instrument of Pattern Identification for Hwa-Byung to evaluate different responses for six patterns of patients. Results: Scores of all the measurements improved significantly for each group, showing no significant differences between the two groups. In the case of deficiency of both Qi and blood pattern, the Sihogayonggolmoryeo-tang group showed a significant decrease in the HAM-A score compared to the placebo group. Conclusions: The effect of Sihogayonggolmoryeo-tang on Hwa-byung did not exceed that of the placebo. Further studies involving more elaborate pattern identification are needed.

• Proceedings of the KIEE Conference
• /
• 1998.07a
• /
• pp.371-374
• /
• 1998

The construction of the transportation history database system is to serve the scheduling and seat inventory controling. Recently, lots of countries have been faced with the advance era because of the new railway transportation system, like the high speed railway and/or magnetic levitation vehicle system. This can be reasonably translated as those of operators are willing to provide the more various and high quality schedule to the customer. Those operators these ideas make possible to forecast that scheduling process is going to be complicated more and more. The seat inventory control, so to speak Yield Management System(YMS), goes a long way to improve the total passenger revenue at the railway business. The YMS forecasts the number of the last reservation value(DCP# END) and recommends the optimal values on the seat sales. The history database system contains infra-data(ie, train, seat, sales) that will be the foundation of scheduling and seat inventory control application programs. The development of the application programs are reserved to the next step. The database system is installed on the pc platform (IBM compatible), using the DB2(RDBMS). And at next step, the platform and DBMS will be considered whether they can meet the users' requirement or not.